CR1000 Measurement and Control System

CR1000 Measurement and Control System
OPERATOR'S MANUAL
Want to get going? Go to the Quickstart (p. 41) section. Want
to see notes pertaining to this preliminary manual release?
Go to Release Notes (p. 34).
CR1000 Measurement and
Control System
Preliminary for OS v.28: 4/13/15
C o p y r i g h t © 2 0 0 0 – 2 0 1 5
C a m p b e l l S c i e n t i f i c , I n c .
Assistance
Products may not be returned without prior authorization. The following
contact information is for Canadian and international clients residing in
countries served by Campbell Scientific (Canada) Corp. directly. Affiliate
companies handle repairs for clients within their territories. Please visit
www.campbellsci.ca to determine which Campbell Scientific company serves
your country.
To obtain a Returned Materials Authorization (RMA), contact CAMPBELL
SCIENTIFIC (CANADA) CORP., phone (780) 454-2505. After a
measurement consultant determines the nature of the problem, an RMA
number will be issued. Please write this number clearly on the outside of the
shipping container. Campbell Scientific’s shipping address is:
CAMPBELL SCIENTIFIC (CANADA) CORP.
RMA#_____
14532 131 Avenue NW
Edmonton, Alberta T5L 4X4
Canada
For all returns, the client must fill out a “Statement of Product Cleanliness and
Decontamination” form and comply with the requirements specified in it. The
form is available from our web site at www.campbellsci.ca/repair. A
completed form must be either emailed to [email protected] or faxed to
(780) 454-2655. Campbell Scientific (Canada) Corp. is unable to process any
returns until we receive this form. If the form is not received within three days
of product receipt or is incomplete, the product will be returned to the client at
the client’s expense. Campbell Scientific (Canada) Corp.f reserves the right to
refuse service on products that were exposed to contaminants that may cause
health or safety concerns for our employees.
Precautions
DANGER — MANY HAZARDS ARE ASSOCIATED WITH INSTALLING, USING, MAINTAINING, AND WORKING ON OR AROUND
TRIPODS, TOWERS, AND ANY ATTACHMENTS TO TRIPODS AND TOWERS SUCH AS SENSORS, CROSSARMS, ENCLOSURES,
ANTENNAS, ETC. FAILURE TO PROPERLY AND COMPLETELY ASSEMBLE, INSTALL, OPERATE, USE, AND MAINTAIN TRIPODS,
TOWERS, AND ATTACHMENTS, AND FAILURE TO HEED WARNINGS, INCREASES THE RISK OF DEATH, ACCIDENT, SERIOUS
INJURY, PROPERTY DAMAGE, AND PRODUCT FAILURE. TAKE ALL REASONABLE PRECAUTIONS TO AVOID THESE HAZARDS.
CHECK WITH YOUR ORGANIZATION'S SAFETY COORDINATOR (OR POLICY) FOR PROCEDURES AND REQUIRED PROTECTIVE
EQUIPMENT PRIOR TO PERFORMING ANY WORK.
Use tripods, towers, and attachments to tripods and towers only for purposes for which they are designed. Do not exceed design
limits. Be familiar and comply with all instructions provided in product manuals. Manuals are available at www.campbellsci.ca or by
telephoning (780) 454-2505 (Canada). You are responsible for conformance with governing codes and regulations, including safety
regulations, and the integrity and location of structures or land to which towers, tripods, and any attachments are attached. Installation
sites should be evaluated and approved by a qualified personnel (e.g. engineer). If questions or concerns arise regarding installation,
use, or maintenance of tripods, towers, attachments, or electrical connections, consult with a licensed and qualified engineer or
electrician.
General
x Prior to performing site or installation work, obtain required approvals and permits.
x Use only qualified personnel for installation, use, and maintenance of tripods and towers, and
any attachments to tripods and towers. The use of licensed and qualified contractors is
highly recommended.
x Read all applicable instructions carefully and understand procedures thoroughly before
beginning work.
x Wear a hardhat and eye protection, and take other appropriate safety precautions while
working on or around tripods and towers.
x Do not climb tripods or towers at any time, and prohibit climbing by other persons. Take
reasonable precautions to secure tripod and tower sites from trespassers.
x Use only manufacturer recommended parts, materials, and tools.
Utility and Electrical
x You can be killed or sustain serious bodily injury if the tripod, tower, or attachments you are
installing, constructing, using, or maintaining, or a tool, stake, or anchor, come in contact
with overhead or underground utility lines.
x Maintain a distance of at least one-and-one-half times structure height, 6 meters (20 feet), or
the distance required by applicable law, whichever is greater, between overhead utility lines
and the structure (tripod, tower, attachments, or tools).
x Prior to performing site or installation work, inform all utility companies and have all
underground utilities marked.
x Comply with all electrical codes. Electrical equipment and related grounding devices should
be installed by a licensed and qualified electrician.
Elevated Work and Weather
x Exercise extreme caution when performing elevated work.
x Use appropriate equipment and safety practices.
x During installation and maintenance, keep tower and tripod sites clear of un-trained or nonessential personnel. Take precautions to prevent elevated tools and objects from dropping.
x Do not perform any work in inclement weather, including wind, rain, snow, lightning, etc.
Maintenance
x Periodically (at least yearly) check for wear and damage, including corrosion, stress cracks,
frayed cables, loose cable clamps, cable tightness, etc. and take necessary corrective actions.
x Periodically (at least yearly) check electrical ground connections.
WHILE EVERY ATTEMPT IS MADE TO EMBODY THE HIGHEST DEGREE OF SAFETY IN ALL CAMPBELL SCIENTIFIC PRODUCTS,
THE CLIENT ASSUMES ALL RISK FROM ANY INJURY RESULTING FROM IMPROPER INSTALLATION, USE, OR MAINTENANCE OF
TRIPODS, TOWERS, OR ATTACHMENTS TO TRIPODS AND TOWERS SUCH AS SENSORS, CROSSARMS, ENCLOSURES, ANTENNAS,
ETC.
Table of Contents
1. Introduction ................................................................ 33
1.1 HELLO .................................................................................................. 33
1.2 Typography ............................................................................................ 33
1.3 Capturing CRBasic Code ....................................................................... 34
2. Cautionary Statements .............................................. 37
3. Initial Inspection ........................................................ 39
4. System Quickstart ..................................................... 41
4.1 Data-Acquisition Systems — Quickstart ............................................... 41
4.2 Sensors — Quickstart ............................................................................ 42
4.3 Datalogger — Quickstart ....................................................................... 43
4.3.1.1 Wiring Panel — Quickstart ................................................. 43
4.4 Power Supplies — Quickstart ................................................................ 44
4.4.1 Internal Battery — Quickstart ...................................................... 45
4.5 Data Retrieval and Telecommunications — Quickstart ........................ 45
4.6 Datalogger Support Software — Quickstart........................................... 46
4.7 Tutorial: Measuring a Thermocouple ..................................................... 46
4.7.1 What You Will Need .................................................................... 46
4.7.2 Hardware Setup ............................................................................ 47
4.7.2.1 External Power Supply........................................................ 47
4.7.3 PC200W Software Setup .............................................................. 48
4.7.4 Write CRBasic Program with Short Cut ....................................... 50
4.7.4.1 Procedure: (Short Cut Steps 1 to 5) ..................................... 50
4.7.4.2 Procedure: (Short Cut Steps 6 to 7)..................................... 51
4.7.4.3 Procedure: (Short Cut Step 8) ............................................. 52
4.7.4.4 Procedure: (Short Cut Steps 9 to 12) ................................... 53
4.7.4.5 Procedure: (Short Cut Steps 13 to 14) ................................. 54
4.7.5 Send Program and Collect Data .................................................... 55
4.7.5.1 Procedure: (PC200W Step 1) .............................................. 55
4.7.5.2 Procedure: (PC200W Steps 2 to 4) ..................................... 55
4.7.5.3 Procedure: (PC200W Step 5) .............................................. 56
4.7.5.4 Procedure: (PC200W Step 6) .............................................. 57
4.7.5.5 Procedure: (PC200W Steps 7 to 10) ................................... 58
4.7.5.6 Procedure: (PC200W Steps 11 to 12) ................................. 59
4.7.5.7 Procedure: (PC200W Steps 13 to 14) ................................. 59
5. System Overview ....................................................... 61
5.1 Measurements — Overview ................................................................... 62
5.1.1 Time Keeping — Overview.......................................................... 63
5.1.2 Analog Measurements — Overview............................................. 63
5.1.2.1 Voltage Measurements — Overview .................................. 63
5.1.2.1.1 Single-Ended Measurements — Overview................ 65
5.1.2.1.2 Differential Measurements — Overview................... 66
5.1.2.2 Current Measurements — Overview................................... 66
5.1.2.3 Resistance Measurements — Overview .............................. 67
5.1.2.3.1 Voltage Excitation ..................................................... 67
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Table of Contents
5.1.2.4 Strain Measurements — Overview ..................................... 68
5.1.3 Pulse Measurements — Overview ................................................ 68
5.1.3.1 Pulses Measured .................................................................. 69
5.1.3.2 Pulse-Input Channels .......................................................... 69
5.1.3.3 Pulse Sensor Wiring ............................................................ 70
5.1.4 Period Averaging — Overview .................................................... 70
5.1.5 Vibrating-Wire Measurements — Overview ................................ 71
5.1.6 Reading Smart Sensors — Overview ........................................... 71
5.1.6.1 SDI-12 Sensor Support — Overview .................................. 72
5.1.6.2 RS-232 — Overview ........................................................... 72
5.1.7 Field Calibration — Overview ..................................................... 73
5.1.8 Cabling Effects — Overview ........................................................ 74
5.1.9 Synchronizing Measurements — Overview ................................. 74
5.2 PLC Control — Overview...................................................................... 74
5.3 Datalogger — Overview ........................................................................ 75
5.3.1 Time Keeping — Overview .......................................................... 75
5.3.2 Wiring Panel — Overview ........................................................... 76
5.3.2.1 Switched Voltage Output — Overview............................... 78
5.3.2.2 Voltage Excitation — Overview ....................................... 79
5.3.2.3 Grounding Terminals .......................................................... 80
5.3.2.4 Power Terminals ................................................................. 80
5.3.2.4.1 Power In..................................................................... 80
5.3.2.4.2 Power Out Terminals ................................................. 80
5.3.2.5 Communication Ports .......................................................... 81
5.3.2.5.1 CS I/O Port ................................................................ 81
5.3.2.5.2 RS-232 Ports .............................................................. 82
5.3.2.5.3 Peripheral Port ........................................................... 82
5.3.2.5.4 SDI-12 Ports .............................................................. 82
5.3.2.5.5 SDM Port ................................................................... 82
5.3.2.5.6 CPI Port ..................................................................... 82
5.3.2.5.7 Ethernet Port .............................................................. 83
5.3.3 Keyboard Display — Overview ................................................... 83
5.3.3.1 Character Set ....................................................................... 83
5.3.3.2 Custom Menus — Overview ............................................... 84
5.3.4 Measurement and Control Peripherals — Overview .................... 85
5.3.5 Power Supplies — Overview ........................................................ 85
5.3.6 CR1000 Configuration — Overview ............................................ 86
5.3.7 CRBasic Programming — Overview............................................ 86
5.3.8 Memory — Overview ................................................................... 87
5.3.9 Data Retrieval and Telecommunications — Overview ................ 88
5.3.9.1 PakBus® Communications — Overview ............................ 88
5.3.9.2 Telecommunications ........................................................... 89
5.3.9.3 Mass-Storage Device .......................................................... 89
5.3.9.4 Memory Card (CRD: Drive) — Overview.......................... 89
5.3.9.5 Data-File Formats in CR1000 Memory............................... 90
5.3.9.6 Data Format on Computer ................................................... 90
5.3.10 Alternate Telecommunications — Overview ............................. 90
5.3.10.1 Modbus.............................................................................. 91
5.3.10.2 DNP3 — Overview ........................................................... 91
5.3.10.3 TCP/IP — Overview ......................................................... 91
5.3.11 Security — Overview ................................................................. 92
5.3.12 Maintenance — Overview .......................................................... 93
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Table of Contents
5.3.12.1 Protection from Moisture — Overview ............................ 93
5.3.12.2 Protection from Voltage Transients .................................. 94
5.3.12.3 Factory Calibration ........................................................... 94
5.3.12.4 Internal Battery — Details ................................................ 94
5.4 Datalogger Support Software — Overview ........................................... 95
6. Specifications ............................................................ 97
7. Installation .................................................................. 99
7.1
7.2
7.3
7.4
7.5
7.6
7.7
7.8
Protection from Moisture — Details ...................................................... 99
Temperature Range ................................................................................ 99
Enclosures .............................................................................................. 99
Power Supplies — Details ................................................................... 100
7.4.1 CR1000 Power Requirement ...................................................... 101
7.4.2 Calculating Power Consumption ................................................ 101
7.4.3 Power Sources ............................................................................ 101
7.4.3.1 Vehicle Power Connections .............................................. 102
7.4.4 Uninterruptable Power Supply (UPS)......................................... 102
7.4.5 External Power Supply Installation ............................................ 103
Switched Voltage Output — Details .................................................... 103
7.5.1 Switched-Voltage Excitation ...................................................... 104
7.5.2 Continuous Regulated (5V Terminal)......................................... 104
7.5.3 Continuous Unregulated Voltage (12V Terminal) ..................... 104
7.5.4 Switched Unregulated Voltage (SW12 Terminal) ...................... 105
Grounding ............................................................................................ 105
7.6.1 ESD Protection ........................................................................... 105
7.6.1.1 Lightning Protection ......................................................... 107
7.6.2 Single-Ended Measurement Reference ....................................... 108
7.6.3 Ground-Potential Differences ..................................................... 109
7.6.3.1 Soil Temperature Thermocouple....................................... 109
7.6.3.2 External Signal Conditioner .............................................. 109
7.6.4 Ground Looping in Ionic Measurements .................................... 109
CR1000 Configuration — Details ........................................................ 111
7.7.1 Configuration Tools .................................................................... 111
7.7.1.1 Configuration with DevConfig ......................................... 111
7.7.1.2 Network Planner ............................................................... 112
7.7.1.2.1 Overview ................................................................. 113
7.7.1.2.2 Basics ...................................................................... 114
7.7.1.3 Configuration with Status/Settings/DTI ............................ 114
7.7.1.4 Configuration with Executable CPU: Files ....................... 115
7.7.1.4.1 Default.cr1 File ........................................................ 116
7.7.1.4.2 Executable File Run Priorities ................................. 116
7.7.2 CR1000 Configuration — Details .............................................. 117
7.7.2.1 Updating the Operating System (OS)................................ 117
7.7.2.1.1 OS Update with DevConfig Send OS Tab............... 118
7.7.2.1.2 OS Update with DevConfig ..................................... 119
7.7.2.1.3 OS Update with DevConfig ..................................... 119
7.7.2.1.4 OS Update with DevConfig ..................................... 121
7.7.2.2 Restoring Factory Defaults ............................................... 122
7.7.2.3 Saving and Restoring Configurations ............................... 122
CRBasic Programming — Details ....................................................... 122
7.8.1 Program Structure ....................................................................... 123
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Table of Contents
7.8.2 Writing and Editing Programs .................................................... 125
7.8.2.1 Short Cut Programming Wizard ........................................ 125
7.8.2.2 CRBasic Editor ................................................................. 125
7.8.2.2.1 Inserting Comments into Program ........................... 126
7.8.2.2.2 Conserving Program Memory ................................. 126
7.8.3 Sending CRBasic Programs ........................................................ 126
7.8.3.1 Preserving Data at Program Send ...................................... 127
7.8.4 Programming Syntax .................................................................. 128
7.8.4.1 Program Statements .......................................................... 128
7.8.4.1.1 Multiple Statements on One Line ............................ 128
7.8.4.1.2 One Statement on Multiple Lines ............................ 128
7.8.4.2 Single-Statement Declarations .......................................... 129
7.8.4.3 Declaring Variables ........................................................... 129
7.8.4.3.1 Declaring Data Types .............................................. 130
7.8.4.3.2 Dimensioning Numeric Variables ........................... 134
7.8.4.3.3 Dimensioning String Variables................................ 134
7.8.4.3.4 Declaring Flag Variables ......................................... 135
7.8.4.4 Declaring Arrays ............................................................... 135
7.8.4.5 Declaring Local and Global Variables .............................. 136
7.8.4.6 Initializing Variables ......................................................... 137
7.8.4.7 Declaring Constants .......................................................... 137
7.8.4.7.1 Predefined Constants ............................................... 138
7.8.4.8 Declaring Aliases and Units .............................................. 138
7.8.4.9 Numerical Formats ............................................................ 139
7.8.4.10 Multi-Statement Declarations ......................................... 140
7.8.4.10.1 Declaring Data Tables ........................................... 140
7.8.4.10.2 Declaring Subroutines ........................................... 147
7.8.4.10.3 'Include' File .......................................................... 147
7.8.4.10.4 Declaring Subroutines ........................................... 150
7.8.4.10.5 Declaring Incidental Sequences ............................. 150
7.8.4.11 Execution and Task Priority ............................................ 151
7.8.4.11.1 Pipeline Mode ........................................................ 152
7.8.4.11.2 Sequential Mode .................................................... 153
7.8.4.12 Execution Timing ............................................................ 154
7.8.4.12.1 Scan() / NextScan .................................................. 154
7.8.4.12.2 SlowSequence / EndSequence ............................... 155
7.8.4.12.3 SubScan() / NextSubScan ...................................... 156
7.8.4.12.4 Scan Priorities in Sequential Mode........................ 156
7.8.4.13 Programming Instructions ............................................... 158
7.8.4.13.1 Measurement and Data-Storage Processing........... 158
7.8.4.13.2 Argument Types .................................................... 159
7.8.4.13.3 Names in Arguments ............................................. 159
7.8.4.14 Expressions in Arguments ............................................... 160
7.8.4.15 Programming Expression Types ..................................... 160
7.8.4.15.1 Floating-Point Arithmetic ...................................... 161
7.8.4.15.2 Mathematical Operations ....................................... 161
7.8.4.15.3 Expressions with Numeric Data Types .................. 162
7.8.4.15.4 Logical Expressions ............................................... 164
7.8.4.15.5 String Expressions ................................................. 166
7.8.4.16 Programming Access to Data Tables .............................. 167
7.8.4.17 Programming to Use Signatures ...................................... 169
7.9 Programming Resource Library ........................................................... 169
12
Table of Contents
7.9.1 Advanced Programming Techniques .......................................... 169
7.9.1.1 Capturing Events ............................................................... 169
7.9.1.2 Conditional Output............................................................ 170
7.9.1.3 Groundwater Pump Test ................................................... 171
7.9.1.4 Miscellaneous Features ..................................................... 174
7.9.1.5 PulseCountReset Instruction ............................................. 177
7.9.1.6 Scaling Array .................................................................... 177
7.9.1.7 Signatures: Example Programs ......................................... 178
7.9.1.7.1 Text Signature ......................................................... 178
7.9.1.7.2 Binary Runtime Signature ....................................... 178
7.9.1.7.3 Executable Code Signatures .................................... 178
7.9.1.8 Use of Multiple Scans ....................................................... 179
7.9.2 Compiling: Conditional Code ..................................................... 180
7.9.3 Displaying Data: Custom Menus — Details ............................... 182
7.9.4 Data Input: Loading Large Data Sets ......................................... 188
7.9.5 Data Input: Array-Assigned Expression ..................................... 188
7.9.6 Data Output: Calculating Running Average ............................... 192
7.9.7 Data Output: Triggers and Omitting Samples ............................ 195
7.9.8 Data Output: Two Intervals in One Data Table .......................... 197
7.9.9 Data Output: Using Data Type Bool8......................................... 198
7.9.10 Data Output: Using Data Type NSEC ...................................... 202
7.9.10.1 NSEC Options ................................................................. 202
7.9.11 Data Output: Writing High-Frequency Data to Memory
Cards ............................................................................................. 205
7.9.11.1 TableFile() with Option 64.............................................. 206
7.9.11.2 TableFile() with Option 64 Replaces CardOut() ............. 206
7.9.11.3 TableFile() with Option 64 Programming ....................... 207
7.9.11.4 Converting TOB3 Files with CardConvert ..................... 207
7.9.11.5 TableFile() with Option 64 Q & A .................................. 208
7.9.12 Field Calibration — Details ...................................................... 210
7.9.12.1 Field Calibration CAL Files ............................................ 210
7.9.12.2 Field Calibration Programming....................................... 211
7.9.12.3 Field Calibration Wizard Overview ................................ 211
7.9.12.4 Field Calibration Numeric Monitor Procedures .............. 211
7.9.12.4.1 One-Point Calibrations (Zero or Offset) ................ 212
7.9.12.4.2 Two-Point Calibrations (gain and offset) .............. 213
7.9.12.4.3 Zero Basis Point Calibration.................................. 213
7.9.12.5 Field Calibration Examples ............................................. 213
7.9.12.5.1 FieldCal() Zero or Tare (Opt 0) Example .............. 214
7.9.12.5.2 FieldCal() Offset (Opt 1) Example ........................ 216
7.9.12.5.3 FieldCal() Slope and Offset (Opt 2) Example ....... 218
7.9.12.5.4 FieldCal() Slope (Opt 3) Example ......................... 220
7.9.12.5.5 FieldCal() Zero Basis (Opt 4) Example -- 8 10
30 223
7.9.12.6 Field Calibration Strain Examples .................................. 223
7.9.12.6.1 Field Calibration Strain Examples ......................... 223
7.9.12.6.2 Field Calibration Strain Examples ......................... 224
7.9.12.6.3 FieldCalStrain() Quarter-Bridge Shunt Example... 226
7.9.12.6.4 FieldCalStrain() Quarter-Bridge Zero ................... 227
7.9.13 Measurement: Excite, Delay, Measure ..................................... 228
7.9.14 Measurement: Faster Analog Rates .......................................... 229
7.9.14.1 Measurements from 1 to 100 Hz ..................................... 230
7.9.14.2 Measurement Rate: 101 to 600 Hz .................................. 231
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Table of Contents
7.9.14.2.1 Measurements from 101 to 600 Hz 2..................... 232
7.9.14.3 Measurement Rate: 601 to 2000 Hz ................................ 233
7.9.15 Measurement: PRT ................................................................... 234
7.9.15.1 0HDVXULQJ37Vȍ357V ................................... 235
7.9.15.1.1 Self-Heating and Resolution .................................. 235
7.9.15.1.2 PRT Calculation Standards .................................... 235
7.9.15.2 PT100 in Four-Wire Half-Bridge .................................... 238
7.9.15.2.1 Calculating the Excitation Voltage ........................ 239
7.9.15.2.2 Calculating the BrHalf4W() Multiplier ................. 239
7.9.15.2.3 Choosing Rf ........................................................... 240
7.9.15.3 PT100 in Three-Wire Half Bridge................................... 241
7.9.15.4 PT100 in Four-Wire Full-Bridge..................................... 242
7.9.16 PLC Control — Details............................................................. 244
7.9.17 Serial I/O: Capturing Serial Data .............................................. 245
7.9.17.1 Introduction ..................................................................... 245
7.9.17.2 I/O Ports .......................................................................... 246
7.9.17.3 Protocols.......................................................................... 247
7.9.17.4 Glossary of Serial I/O Terms .......................................... 247
7.9.17.5 Serial I/O CRBasic Programming ................................... 249
7.9.17.5.1 Serial I/O Programming Basics ............................. 250
7.9.17.5.2 Serial I/O Input Programming Basics .................... 251
7.9.17.5.3 Serial I/O Output Programming Basics ................. 252
7.9.17.5.4 Serial I/O Translating Bytes .................................. 253
7.9.17.5.5 Serial I/O Memory Considerations ........................ 253
7.9.17.5.6 Demonstration Program ......................................... 254
7.9.17.6 Serial I/O Application Testing ........................................ 256
7.9.17.6.1 Configure HyperTerminal ..................................... 256
7.9.17.6.2 Create Send-Text File ............................................ 258
7.9.17.6.3 Create Text-Capture File ....................................... 258
7.9.17.6.4 Serial I/O Example II ............................................. 259
7.9.17.7 Serial I/O Q & A ............................................................. 264
7.9.18 Serial I/O: SDI-12 Sensor Support — Programming
Resource ........................................................................................ 267
7.9.18.1 SDI-12 Transparent Mode ............................................... 267
7.9.18.1.1 SDI-12 Transparent Mode Commands .................. 268
7.9.18.2 SDI-12 Recorder Mode ................................................... 272
7.9.18.3 SDI-12 Sensor Mode ....................................................... 279
7.9.18.4 SDI-12 Power Considerations ......................................... 281
7.9.19 String Operations ...................................................................... 282
7.9.19.1 String Operators .............................................................. 282
7.9.19.2 String Concatenation ....................................................... 283
7.9.19.3 String NULL Character ................................................... 285
7.9.19.4 Inserting String Characters .............................................. 286
7.9.19.5 Extracting String Characters ........................................... 286
7.9.19.6 String Use of ASCII / ANSII Codes ............................... 287
7.9.19.7 Formatting Strings ........................................................... 287
7.9.19.8 Formatting String Hexadecimal Variables ...................... 288
7.9.20 Subroutines ............................................................................... 288
7.9.21 TCP/IP — Details ..................................................................... 289
7.9.21.1 PakBus Over TCP/IP and Callback ................................. 290
7.9.21.2 Default HTTP Web Server .............................................. 291
7.9.21.3 Custom HTTP Web Server ............................................. 291
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Table of Contents
7.9.21.4 FTP Server ...................................................................... 294
7.9.21.5 FTP Client ....................................................................... 294
7.9.21.6 Telnet .............................................................................. 295
7.9.21.7 SNMP.............................................................................. 295
7.9.21.8 Ping (IP) .......................................................................... 295
7.9.21.9 Micro-Serial Server ......................................................... 295
7.9.21.10 Modbus TCP/IP............................................................. 295
7.9.21.11 DHCP ............................................................................ 295
7.9.21.12 DNS .............................................................................. 296
7.9.21.13 SMTP ............................................................................ 296
7.9.22 Wind Vector ............................................................................. 296
7.9.22.1 OutputOpt Parameters ..................................................... 296
7.9.22.2 Wind Vector Processing .................................................. 297
7.9.22.2.1 Measured Raw Data .............................................. 298
7.9.22.2.2 Calculations ........................................................... 298
8. Operation .................................................................. 303
8.1 Measurements — Details ..................................................................... 303
8.1.1 Time Keeping — Details ............................................................ 303
8.1.1.1 Time Stamps ..................................................................... 303
8.1.2 Analog Measurements — Details ............................................... 305
8.1.2.1 Voltage Measurements — Details..................................... 305
8.1.2.1.1 Voltage Measurement Mechanics............................ 305
8.1.2.1.2 Voltage Measurement Limitations .......................... 308
8.1.2.1.3 Voltage Measurement Quality ................................. 311
8.1.2.2 Thermocouple Measurements —- Details......................... 327
8.1.2.2.1 Thermocouple Error Analysis ................................. 327
8.1.2.2.2 Use of External Reference Junction ........................ 336
8.1.2.3 Current Measurements — Details ..................................... 337
8.1.2.4 Resistance Measurements — Details ................................ 337
8.1.2.4.1 Ac Excitation ........................................................... 341
8.1.2.4.2 Resistance Measurements — Accuracy................... 341
8.1.2.5 Strain Measurements — Details........................................ 342
8.1.2.6 Auto-Calibration — Details .............................................. 344
8.1.2.6.1 Auto Calibration Process ......................................... 344
8.1.3 Pulse Measurements — Details .................................................. 349
8.1.3.1 Pulse Measurement Terminals .......................................... 352
8.1.3.2 Low-Level Ac Measurements — Details .......................... 352
8.1.3.3 High-Frequency Measurements ........................................ 353
8.1.3.3.1 Frequency Resolution .............................................. 353
8.1.3.3.2 Frequency Measurement Q & A .............................. 354
8.1.3.4 Switch-Closure and Open-Collector Measurements ......... 355
8.1.3.5 Edge Timing...................................................................... 355
8.1.3.6 Edge Counting .................................................................. 356
8.1.3.7 Pulse Measurement Tips ................................................... 356
8.1.3.7.1 TimerIO() NAN Conditions .................................... 359
8.1.3.7.2 Input Filters and Signal Attenuation ........................ 359
8.1.4 Period Averaging — Details ....................................................... 360
8.1.5 Vibrating-Wire Measurements — Details .................................. 361
8.1.5.1 Time-Domain Measurement ............................................. 362
8.1.6 Reading Smart Sensors — Details .............................................. 362
8.1.6.1 RS-232 and TTL ............................................................... 362
15
Table of Contents
8.2
8.3
8.4
8.5
16
8.1.6.2 SDI-12 Sensor Support — Details .................................... 363
8.1.7 Field Calibration — Overview ................................................... 363
8.1.8 Cabling Effects ........................................................................... 364
8.1.8.1 Analog-Sensor Cables ....................................................... 364
8.1.8.2 Pulse Sensors..................................................................... 364
8.1.8.3 RS-232 Sensors ................................................................. 364
8.1.8.4 SDI-12 Sensors ................................................................. 364
8.1.9 Synchronizing Measurements ..................................................... 365
Measurement and Control Peripherals — Details ................................ 366
8.2.1 Analog-Input Modules ................................................................ 366
8.2.2 Pulse-Input Modules ................................................................... 367
8.2.2.1 Low-Level Ac Input Modules — Overview ..................... 367
8.2.3 Serial I/O Modules — Details .................................................... 367
8.2.4 Terminal-Input Modules ............................................................. 367
8.2.5 Vibrating-Wire Modules ............................................................. 367
8.2.6 Analog-Output Modules ............................................................. 367
8.2.7 PLC Control Modules — Overview ........................................... 368
8.2.7.1 Terminals Configured for Control..................................... 368
8.2.7.2 Relays and Relay Drivers .................................................. 369
8.2.7.3 Component-Built Relays ................................................... 369
Memory ................................................................................................ 370
8.3.1 Storage Media ............................................................................. 370
8.3.1.1 Memory Drives — On-Board ........................................... 374
8.3.1.1.1 Data Table SRAM ................................................... 374
8.3.1.1.2 CPU: Drive .............................................................. 374
8.3.1.1.3 USR: Drive .............................................................. 375
8.3.1.1.4 USB: Drive .............................................................. 375
8.3.1.2 Memory Card (CRD: Drive) — Details ............................ 376
8.3.2 Data-File Formats ....................................................................... 377
8.3.3 Resetting the CR1000 ................................................................. 381
8.3.3.1 Full Memory Reset ............................................................ 381
8.3.3.2 Program Send Reset .......................................................... 381
8.3.3.3 Manual Data-Table Reset .................................................. 382
8.3.3.4 Formatting Drives ............................................................. 382
8.3.4 File Management ........................................................................ 382
8.3.4.1 File Attributes ................................................................... 383
8.3.4.2 Files Manager .................................................................... 384
8.3.4.3 Data Preservation .............................................................. 385
8.3.4.4 Powerup.ini File — Details ............................................... 386
8.3.4.4.1 Creating and Editing Powerup.ini............................ 387
8.3.4.5 File Management Q & A ................................................... 389
8.3.5 File Names .................................................................................. 389
8.3.6 File-System Errors ...................................................................... 389
8.3.7 Memory Q & A........................................................................... 391
Data Retrieval and Telecommunications — Details ............................ 391
8.4.1 Protocols ..................................................................................... 392
8.4.2 Conserving Bandwidth ............................................................... 392
8.4.3 Initiating Telecommunications (Callback).................................. 392
PakBus® Communications — Details ................................................. 393
8.5.1 PakBus Addresses....................................................................... 393
8.5.2 Nodes: Leaf Nodes and Routers ................................................. 394
8.5.2.1 Router and Leaf-Node Configuration................................ 394
Table of Contents
8.5.3 Linking PakBus Nodes: Neighbor Discovery ............................. 395
8.5.3.1 Hello-Message .................................................................. 396
8.5.3.2 Beacon............................................................................... 396
8.5.3.3 Hello-Request ................................................................... 396
8.5.3.4 Neighbor Lists ................................................................... 396
8.5.3.5 Adjusting Links ................................................................. 396
8.5.3.6 Maintaining Links ............................................................. 397
8.5.4 PakBus Troubleshooting............................................................. 397
8.5.4.1 Link Integrity .................................................................... 397
8.5.4.1.1 Automatic Packet-Size Adjustment ......................... 397
8.5.4.2 Ping (PakBus) ................................................................... 398
8.5.4.3 Traffic Flow ...................................................................... 398
8.5.5 LoggerNet Network-Map Configuration .................................... 398
8.5.6 PakBus LAN Example................................................................ 400
8.5.6.1 LAN Wiring ...................................................................... 400
8.5.6.2 LAN Setup ........................................................................ 401
8.5.6.3 LoggerNet Setup ............................................................... 403
8.5.7 Route Filters ............................................................................... 405
8.5.8 PakBusRoutes ............................................................................. 405
8.5.9 Neighbors ................................................................................... 406
8.5.10 PakBus Encryption ................................................................... 406
8.6 Alternate Telecommunications — Details ........................................... 407
8.6.1 DNP3 — Details ......................................................................... 408
8.6.1.1 DNP3 Introduction ............................................................ 408
8.6.1.2 Programming for DNP3 .................................................... 408
8.6.1.2.1 Declarations (DNP3 Programming) ........................ 408
8.6.1.2.2 CRBasic Instructions (DNP3) ................................. 409
8.6.1.2.3 Programming for DNP3 Data Acquisition............... 410
8.6.2 Modbus — Details ...................................................................... 411
8.6.2.1 Modbus Terminology ........................................................ 412
8.6.2.1.1 Glossary of Modbus Terms ..................................... 412
8.6.2.2 Programming for Modbus ................................................. 413
8.6.2.2.1 Declarations (Modbus Programming) ..................... 413
8.6.2.2.2 CRBasic Instructions (Modbus) .............................. 414
8.6.2.2.3 Addressing (ModbusAddr) ...................................... 414
8.6.2.2.4 Supported Modbus Function Codes......................... 415
8.6.2.2.5 Reading Inverse-Format Modbus Registers ............ 415
8.6.2.3 Troubleshooting (Modbus)................................................ 415
8.6.2.4 Modbus over IP ................................................................. 416
8.6.2.5 Modbus Q and A ............................................................... 416
8.6.2.6 Converting Modbus 16-Bit to 32-Bit Longs ..................... 416
8.6.3 TCP/IP — Details ....................................................................... 417
8.6.3.1 PakBus Over TCP/IP and Callback ................................... 418
8.6.3.2 Default HTTP Web Server ................................................ 418
8.6.3.3 Custom HTTP Web Server ............................................... 419
8.6.3.4 FTP Server ........................................................................ 422
8.6.3.5 FTP Client ......................................................................... 422
8.6.3.6 Telnet ................................................................................ 422
8.6.3.7 SNMP................................................................................ 422
8.6.3.8 Ping (IP) ............................................................................ 423
8.6.3.9 Micro-Serial Server ........................................................... 423
8.6.3.10 Modbus TCP/IP............................................................... 423
8.6.3.11 DHCP .............................................................................. 423
17
Table of Contents
8.6.3.12 DNS................................................................................. 423
8.6.3.13 SMTP .............................................................................. 423
8.6.3.14 Web API .......................................................................... 423
8.6.3.14.1 Authentication ....................................................... 424
8.6.3.14.2 Command Syntax .................................................. 425
8.6.3.14.3 Time Syntax........................................................... 427
8.6.3.14.4 Data Management — BrowseSymbols
Command ......................................................................... 427
8.6.3.14.5 Data Management — DataQuery Command ......... 431
8.6.3.14.6 Control — SetValueEx Command ........................ 436
8.6.3.14.7 Clock Functions — ClockSet Command ............... 439
8.6.3.14.8 Clock Functions — ClockCheck Command .......... 440
8.6.3.14.9 File Management — Sending a File to a
Datalogger ........................................................................ 442
8.6.3.14.10 File Management — FileControl Command ....... 444
8.6.3.14.11 File Management — ListFiles Command ............ 445
8.6.3.14.12 File Management — NewestFile Command........ 449
8.7 Datalogger Support Software — Details .............................................. 450
8.8 Keyboard Display — Details ............................................................... 451
8.8.1 Data Display ............................................................................... 454
8.8.1.1 Real-Time Tables and Graphs ........................................... 455
8.8.1.2 Real-Time Custom ............................................................ 455
8.8.1.3 Final-Memory Tables ........................................................ 457
8.8.2 Run/Stop Program ...................................................................... 458
8.8.3 File Display................................................................................. 459
8.8.3.1 File: Edit ............................................................................ 459
8.8.4 PCCard (Memory Card) Display ................................................ 461
8.8.5 Ports and Status........................................................................... 462
8.8.6 Settings ....................................................................................... 462
8.8.6.1 Set Time / Date.................................................................. 463
8.8.6.2 PakBus Settings................................................................. 463
8.8.7 Configure Display ....................................................................... 463
8.9 Program and OS File Compression Q and A........................................ 463
8.10 Memory Cards and Record Numbers ................................................. 466
8.11 Security — Details ............................................................................. 467
8.11.1 Vulnerabilities .......................................................................... 468
8.11.2 Pass-Code Lockout ................................................................... 469
8.11.2.1 Pass-Code Lockout By-Pass............................................ 470
8.11.3 Passwords ................................................................................. 470
8.11.3.1 .csipasswd ....................................................................... 470
8.11.3.2 PakBus Instructions ......................................................... 470
8.11.3.3 TCP/IP Instructions ......................................................... 471
8.11.3.4 Settings — Passwords ..................................................... 471
8.11.4 File Encryption ......................................................................... 471
8.11.5 Communication Encryption ...................................................... 471
8.11.6 Hiding Files .............................................................................. 471
8.11.7 Signatures ................................................................................. 472
9. Maintenance — Details ............................................ 473
9.1 Protection from Moisture — Details .................................................... 473
9.2 Replacing the Internal Battery .............................................................. 473
18
Table of Contents
9.3 Factory Calibration or Repair Procedure.............................................. 476
10. Troubleshooting .................................................... 479
10.1 Troubleshooting — Essential Tools ................................................... 479
10.2 Troubleshooting — Basic Procedure ................................................. 479
10.3 Troubleshooting — Error Sources ..................................................... 479
10.4 Troubleshooting — Status Table........................................................ 481
10.5 Programming ...................................................................................... 481
10.5.1 Program Does Not Compile...................................................... 481
10.5.2 Program Compiles / Does Not Run Correctly .......................... 481
10.5.3 NAN and ±INF ......................................................................... 482
10.5.3.1 Measurements and NAN ................................................. 482
10.5.3.1.1 Voltage Measurements .......................................... 482
10.5.3.1.2 SDI-12 Measurements ........................................... 482
10.5.3.2 Floating-Point Math, NAN, and ±INF ............................ 482
10.5.3.3 Data Types, NAN, and ±INF .......................................... 483
10.5.3.4 Output Processing and NAN ........................................... 484
10.5.4 Status Table as Debug Resource............................................... 485
10.5.4.1 CompileResults ............................................................... 485
10.5.4.2 SkippedScan .................................................................... 487
10.5.4.3 SkippedSlowScan............................................................ 487
10.5.4.4 SkippedRecord ................................................................ 488
10.5.4.5 ProgErrors ....................................................................... 488
10.5.4.6 MemoryFree .................................................................... 488
10.5.4.7 VarOutOfBounds ............................................................ 488
10.5.4.8 Watchdog Errors ............................................................. 488
10.5.4.8.1 Status Table WatchdogErrors ................................ 489
10.5.4.8.2 Watchdoginfo.txt File ............................................ 489
10.6 Troubleshooting — Operating Systems ............................................. 490
10.7 Troubleshooting — Auto-Calibration Errors ..................................... 490
10.8 Communications ................................................................................ 490
10.8.1 RS-232 ...................................................................................... 490
10.8.2 Communicating with Multiple PCs .......................................... 491
10.8.3 Comms Memory Errors ............................................................ 491
10.8.3.1 CommsMemFree(1) ........................................................ 491
10.8.3.2 CommsMemFree(2) ........................................................ 492
10.8.3.3 CommsMemFree(3) ........................................................ 493
10.9 Troubleshooting — Power Supplies................................................... 494
10.9.1 Troubleshooting Power Supplies — Overview ........................ 494
10.9.2 Troubleshooting Power Supplies — Examples -- 8 10 30 ........ 494
10.9.3 Troubleshooting Power Supplies — Procedures ...................... 495
10.9.3.1 Battery Test ..................................................................... 495
10.9.3.2 Charging Regulator with Solar-Panel Test...................... 496
10.9.3.3 Charging Regulator with Transformer Test .................... 498
10.9.3.4 Adjusting Charging Voltage ........................................... 499
10.10 Terminal Mode ................................................................................. 501
10.10.1 Serial Talk Through and Comms Watch ................................ 503
10.11 Logs.................................................................................................. 504
10.12 Troubleshooting — Data Recovery .................................................. 504
11. Glossary ................................................................. 507
19
Table of Contents
11.1 Terms ................................................................................................. 507
11.2 Concepts ............................................................................................. 533
11.2.1 Accuracy, Precision, and Resolution ........................................ 533
12. Attributions............................................................. 535
Appendices
A. CRBasic Programming Instructions ...................... 537
A.1 Program Declarations .......................................................................... 537
A.1.1 Variable Declarations & Modifiers ............................................ 538
A.1.2 Constant Declarations ................................................................ 539
A.2 Data-Table Declarations ...................................................................... 540
A.2.1 Data-Table Modifiers ................................................................. 540
A.2.2 Data Destinations ....................................................................... 541
A.2.3 Processing for Output to Final-Data Memory ............................ 542
A.2.3.1 Single-Source ................................................................... 542
A.2.3.2 Multiple-Source................................................................ 544
A.3 Single Execution at Compile ............................................................... 544
A.4 Program Control Instructions .............................................................. 545
A.4.1 Common Program Controls ....................................................... 545
A.4.2 Advanced Program Controls ...................................................... 548
A.5 Measurement Instructions ................................................................... 550
A.5.1 Diagnostics ................................................................................ 550
A.5.2 Voltage....................................................................................... 551
A.5.3 Thermocouples........................................................................... 551
A.5.4 Resistive-Bridge Measurements ................................................ 551
A.5.5 Excitation ................................................................................... 552
A.5.6 Pulse and Frequency .................................................................. 553
A.5.7 Digital I/O .................................................................................. 554
A.5.7.1 Control.............................................................................. 554
A.5.7.2 Measurement .................................................................... 555
A.5.8 SDI-12 Sensor Suppport — Instructions ................................... 555
A.5.9 Specific Sensors ......................................................................... 556
A.5.9.1 Wireless Sensor Network ................................................. 558
A.5.10 Peripheral Device Support ....................................................... 559
A.6 PLC Control — Instructions................................................................ 562
A.7 Processing and Math Instructions ........................................................ 563
A.7.1 Mathematical Operators ............................................................. 563
A.7.2 Arithmetic Operators ................................................................. 563
A.7.3 Bitwise Operations ..................................................................... 564
A.7.4 Compound-Assignment Operators............................................. 565
A.7.5 Logical Operators ...................................................................... 565
A.7.6 Trigonometric Functions............................................................ 566
A.7.6.1 Intrinsic Trigonometric Functions .................................... 566
A.7.6.2 Derived Trigonometric Functions .................................... 568
A.7.7 Arithmetic Functions ................................................................. 568
A.7.8 Integrated Processing ................................................................. 570
A.7.9 Spatial Processing ...................................................................... 571
A.7.10 Other Functions........................................................................ 572
20
Table of Contents
A.7.10.1 Histograms ..................................................................... 573
A.8 String Functions .................................................................................. 574
A.8.1 String Operations ....................................................................... 574
A.8.2 String Commands ...................................................................... 575
A.9 Time Keeping — Instructions ............................................................. 578
A.10 Voice-Modem Instructions ................................................................ 580
A.11 Custom Menus — Instructions .......................................................... 581
A.12 Serial Input / Output .......................................................................... 583
A.13 Peer-to-Peer PakBus® Communications........................................... 584
A.14 Variable Management ....................................................................... 589
A.15 File Management ............................................................................... 589
A.16 Data-Table Access and Management ................................................ 592
A.17 TCP/IP — Instructions ...................................................................... 593
A.18 Modem Control ................................................................................. 597
A.19 SCADA ............................................................................................. 597
A.20 Calibration Functions ........................................................................ 598
A.21 Satellite Systems ............................................................................... 599
A.21.1 Argos ....................................................................................... 599
A.21.2 GOES ....................................................................................... 600
A.21.3 OMNISAT ............................................................................... 601
A.21.4 INMARSAT-C ........................................................................ 601
A.22 User-Defined Functions .................................................................... 602
B. Status, Settings, and Data Table Information
(Status/Settings/DTI) ................................................ 603
B.1 Status/Settings/DTI Directories ........................................................... 604
B.2 Status/Settings/DTI Descriptions (Alphabetical)................................. 611
C. Serial Port Pinouts .................................................. 633
C.1 CS I/O Communication Port................................................................ 633
C.2 RS-232 Communication Port............................................................... 633
C.2.1 Pin-Out ....................................................................................... 633
C.2.2 Power States ............................................................................... 634
D. ASCII / ANSI Table ................................................... 637
E. FP2 Data Format ...................................................... 641
F. Endianness .............................................................. 643
G. Supporting Products Lists ..................................... 645
G.1 Dataloggers — List ............................................................................. 645
G.2 Measurement and Control Peripherals — Lists ................................... 645
G.3 Sensor-Input Modules Lists................................................................. 646
G.3.1 Analog-Input Modules List ........................................................ 646
G.3.2 Pulse-Input Modules List ........................................................... 646
G.3.3 Serial I/O Modules List ............................................................. 646
G.3.4 Vibrating-Wire Input Modules List ........................................... 647
21
Table of Contents
G.3.5 Passive Signal Conditioners Lists .............................................. 647
G.3.5.1 Resistive-Bridge TIM Modules List ................................. 647
G.3.5.2 Voltage-Divider Modules List.......................................... 647
G.3.5.3 Current-Shunt Modules List ............................................. 647
G.3.5.4 Transient-Voltage Suppressors List ................................. 648
G.3.6 Terminal-Strip Covers List ........................................................ 648
G.4 PLC Control Modules — Lists ............................................................ 648
G.4.1 Digital-I/O Modules List............................................................ 648
G.4.2 Continuous-Analog-Output (CAO) Modules List ..................... 649
G.4.3 Relay-Drivers — List................................................................. 649
G.4.4 Current-Excitation Modules List ............................................... 649
G.5 Sensors — Lists ................................................................................... 649
G.5.1 Wired-Sensor Types List ........................................................... 650
G.5.2 Wireless-Network Sensors List.................................................. 650
G.6 Data Retrieval and Telecommunication Peripherals — Lists .............. 651
G.6.1 Keyboard Display — List .......................................................... 651
G.6.2 Hardwire, Single-Connection Comms Devices List .................. 652
G.6.3 Hardwire, Networking Devices List .......................................... 652
G.6.4 TCP/IP Links — List ................................................................. 652
G.6.5 Telephone Modems List ............................................................ 652
G.6.6 Private-Network Radios List...................................................... 653
G.6.7 Satellite Transceivers List .......................................................... 653
G.7 Data-Storage Devices — List .............................................................. 653
G.8 Datalogger Support Software — Lists................................................. 654
G.8.1 Starter Software List .................................................................. 654
G.8.2 Datalogger Support Software — List......................................... 654
G.8.2.1 LoggerNet Suite List ........................................................ 655
G.8.3 Software Tools List .................................................................... 656
G.8.4 Software Development Kits List ................................................ 656
G.9 Power Supplies — Products ................................................................ 657
G.9.1 Battery / Regulator Combinations List ...................................... 657
G.9.2 Batteries List .............................................................................. 658
G.9.3 Regulators List ........................................................................... 658
G.9.4 Primary Power Sources List....................................................... 658
G.9.5 24 Vdc Power Supply Kits List ................................................. 659
G.10 Enclosures — Products...................................................................... 659
G.11 Tripods, Towers, and Mounts Lists ................................................... 659
G.12 Enclosures List .................................................................................. 660
Index .............................................................................. 661
List of Figures
Figure 1. Data-Acquisition System Components .......................................... 42
Figure 2. Wiring Panel .................................................................................. 44
Figure 3. Power and Serial Communication Connections ............................. 48
Figure 4. PC200W Main Window ................................................................. 49
Figure 5. Short Cut Temperature Sensor Folder ........................................... 51
Figure 6. Short Cut Thermocouple Wiring -- needs new image for CR6:
1H = U1, 1L = U2 .................................................................................. 52
Figure 7. Short Cut Outputs Tab ................................................................... 53
Figure 8. Short Cut Outputs Tab ................................................................... 54
22
Table of Contents
Figure 9. Short Cut Compile Confirmation ................................................... 54
Figure 10. PC200W Main Window............................................................... 55
Figure 11. PC200W Monitor Data Tab – Public Table ................................. 56
Figure 12. PC200W Monitor Data Tab — Public and OneMin Tables ........ 57
Figure 13. PC200W Collect Data Tab .......................................................... 57
Figure 14. PC200W View Data Utility ......................................................... 58
Figure 15. PC200W View Data Table .......................................................... 59
Figure 16. PC200W View Line Graph .......................................................... 60
Figure 17. Data-Acquisition System — Overview........................................ 62
Figure 18. Analog Sensor Wired to Single-Ended Channel #1 ..................... 64
Figure 19. Analog Sensor Wired to Differential Channel #1 ........................ 64
Figure 20. Simplified Differential-Voltage Measurement Sequence ............ 66
Figure 21. Half-Bridge Wiring Example — Wind Vane Potentiometer ....... 67
Figure 22. Full-Bridge Wiring Example — Pressure Transducer ................. 68
Figure 23. Pulse-Sensor Output-Signal Types .............................................. 69
Figure 24. Pulse-Input Wiring Example — Anemometer ............................. 70
Figure 25. Terminals Configurable for RS-232 Input ................................... 73
Figure 26. Use of RS-232 and Digital I/O when Reading RS-232
Devices................................................................................................... 73
Figure 27. Wiring Panel ................................................................................ 76
Figure 28. Control and Monitoring with C Terminals .................................. 79
Figure 29. CR1000KD Keyboard Display .................................................... 83
Figure 30. Custom Menu Example ............................................................... 84
Figure 31. Enclosure ................................................................................... 100
Figure 32. Connecting to Vehicle Power Supply ........................................ 102
Figure 33. Schematic of Grounds................................................................ 107
Figure 34. Lightning-Protection Scheme .................................................... 108
Figure 35. Model of a Ground Loop with a Resistive Sensor ..................... 110
Figure 36. Device Configuration Utility (DevConfig) ................................ 112
Figure 37. Network Planner Setup .............................................................. 113
Figure 38. Summary of CR1000 Configuration .......................................... 122
Figure 39. CRBasic Editor Program Send File Control window ................ 127
Figure 40. "Include File" Settings Via DevConfig ...................................... 149
Figure 41. "Include File" Settings Via PakBusGraph ................................. 149
Figure 42. Sequential-Mode Scan Priority Flow Diagrams ........................ 158
Figure 43. Custom Menu Example — Home Screen .................................. 183
Figure 44. Custom Menu Example — View Data Window ........................ 183
Figure 45. Custom Menu Example — Make Notes Sub Menu ................... 184
Figure 46. Custom Menu Example — Predefined Notes Pick List ............. 184
Figure 47. Custom Menu Example — Free Entry Notes Window .............. 184
Figure 48. Custom Menu Example — Accept / Clear Notes Window ........ 184
Figure 49. Custom Menu Example — Control Sub Menu .......................... 185
Figure 50. Custom Menu Example — Control LED Pick List ................... 185
Figure 51. Custom Menu Example — Control LED Boolean Pick List ..... 185
Figure 52. Running-Average Frequency Response ..................................... 194
Figure 53. Running-Average Signal Attenuation ........................................ 195
Figure 54. Data from TrigVar Program....................................................... 196
Figure 55. Alarms Toggled in Bit-Shift Example ....................................... 199
Figure 56. Bool8 Data from Bit-Shift Example (Numeric Monitor) ........... 199
Figure 57. Bool8 Data from Bit-Shift Example (PC Data File) .................. 200
Figure 58. Quarter-Bridge Strain-Gage with RC Resistor Shunt ................ 225
Figure 59. Strain-Gage Shunt Calibration Start .......................................... 226
Figure 60. Strain-Gage Shunt Calibration Finish ........................................ 227
23
Table of Contents
Figure 61. Zero Procedure Start .................................................................. 227
Figure 62. Zero Procedure Finish ................................................................ 227
Figure 63. PT100 in Four-Wire Half-Bridge ............................................... 240
Figure 64. PT100 in Three-Wire Half-Bridge ............................................. 242
Figure 65. PT100 in Four-Wire Full-Bridge ............................................... 244
Figure 66. HyperTerminal New Connection Description............................ 256
Figure 67. HyperTerminal Connect-To Settings ......................................... 257
Figure 68. HyperTerminal COM-Port Settings Tab .................................... 257
Figure 69. HyperTerminal ASCII Setup ..................................................... 258
Figure 70. HyperTerminal Send Text-File Example ................................... 258
Figure 71. HyperTerminal Text-Capture File Example .............................. 259
Figure 72. Entering SDI-12 Transparent Mode ........................................... 268
Figure 73. Preconfigured HTML Home Page ............................................. 291
Figure 74. Home Page Created Using WebPageBegin() Instruction........... 292
Figure 75. Customized Numeric-Monitor Web Page .................................. 293
Figure 76. Input Sample Vectors ................................................................. 298
Figure 77. Mean Wind-Vector Graph ......................................................... 299
Figure 78. Standard Deviation of Direction ................................................ 300
Figure 79. Simplified voltage measurement sequence ................................ 306
Figure 80. Programmable Gain Input Amplifier (PGIA) ............................ 306
Figure 81. PGIA with Input-Signal Decomposition .................................... 311
Figure 82. Example voltage measurement accuracy band, including the
effects of percent of reading and offset, for a differential
measurement with input reversal at a temperature between 0 to
40 °C. ................................................................................................... 314
Figure 83. Ac-Power Noise-Rejection Techniques ..................................... 316
Figure 84. Input-voltage rise and transient decay........................................ 318
Figure 85. Settling Time for Pressure Transducer ....................................... 321
Figure 86. Panel-Temperature Error Summary ........................................... 329
Figure 87. Panel-Temperature Gradients (low temperature to high) ........... 329
Figure 88. Panel-Temperature Gradients (high temperature to low) ........... 330
Figure 89. Input Error Calculation .............................................................. 332
Figure 90. Diagram of a Thermocouple Junction Box ................................ 337
Figure 91. Pulse-Sensor Output-Signal Types ............................................ 350
Figure 92. Switch-Closure Pulse Sensor ..................................................... 350
Figure 93. Terminals Configurable for Pulse Input ..................................... 351
Figure 94. Amplitude reduction of pulse-count waveform (before and
after 1 μs time-constant filter) .............................................................. 360
Figure 95. Input Conditioning Circuit for Period Averaging ...................... 361
Figure 96. Vibrating-Wire Sensor ............................................................... 362
Figure 97. Circuit to Limit C Terminal Input to 5 Vdc ............................... 363
Figure 98. Current-Limiting Resistor in a Rain Gage Circuit ..................... 364
Figure 99. Current sourcing from C terminals configured for control ........ 369
Figure 100. Relay Driver Circuit with Relay .............................................. 370
Figure 101. Power Switching without Relay ............................................... 370
Figure 102. PakBus Network Addressing ................................................... 394
Figure 103. Flat Map ................................................................................... 399
Figure 104. Tree Map .................................................................................. 399
Figure 105. Configuration and Wiring of PakBus LAN ............................. 400
Figure 106. DevConfig Deployment Tab .................................................... 401
Figure 107. DevConfig Deployment | ComPorts Settings Tab ................... 402
Figure 108. DevConfig Deployment | Advanced Tab ................................. 402
24
Table of Contents
Figure 109. LoggerNet Network-Map Setup: COM port ............................ 403
Figure 110. LoggerNet Network-Map Setup: PakBusPort.......................... 404
Figure 111. LoggerNet Network-Map Setup: Dataloggers ......................... 404
Figure 112. Preconfigured HTML Home Page ........................................... 419
Figure 113. Home Page Created Using WebPageBegin() Instruction ........ 420
Figure 114. Customized Numeric-Monitor Web Page ................................ 420
Figure 115. Using the Keyboard / Display .................................................. 453
Figure 116. Displaying Data with the Keyboard / Display ......................... 454
Figure 117. Real-Time Tables and Graphs ................................................. 455
Figure 118. Real-Time Custom ................................................................... 456
Figure 119. Final-Memory Tables .............................................................. 457
Figure 120. Run/Stop Program ................................................................... 458
Figure 121. File Display .............................................................................. 459
Figure 122. File: Edit .................................................................................. 460
Figure 123. PCCard (CF Card) Display ...................................................... 461
Figure 124. C Terminals (Ports) Status ....................................................... 462
Figure 125. Settings .................................................................................... 462
Figure 126. Configure Display .................................................................... 463
Figure 127. Loosen Retention Screws......................................................... 474
Figure 128. Pull Edge Away from Panel..................................................... 475
Figure 129. Remove Nuts to Disassemble Canister .................................... 475
Figure 130. Remove and Replace Battery ................................................... 476
Figure 131. Potentiometer R3 on PS100 and CH100 Charger / Regulator . 501
Figure 132. DevConfig Terminal Tab ......................................................... 503
Figure 133. Relationships of Accuracy, Precision, and Resolution ............ 534
List of Tables
Table 1. PC200W EZSetup Wizard Example Selections .............................. 49
Table 2. Differential and Single-Ended Input Terminals .............................. 65
Table 3. Pulse-Input Terminals and Measurements ...................................... 69
Table 4. CR1000 Wiring Panel Terminal Definitions ................................... 77
Table 5. Current Source and Sink Limits .................................................... 103
Table 6. Status/Setting/DTI: Access Points ................................................ 115
Table 7. Common Configuration Actions and Tools .................................. 117
Table 8. CRBasic Program Structure .......................................................... 123
Table 9. Program Send Options that Reset Memory* ................................. 127
Table 10. Data Table Structures .................................................................. 128
Table 11. Data Types in Variable Memory ................................................. 130
Table 12. Data Types in Final-Data Memory.............................................. 131
Table 13. Formats for Entering Numbers in CRBasic ................................ 139
Table 14. Typical Data Table ...................................................................... 141
Table 15. TOA5 Environment Line ............................................................ 141
Table 16. DataInterval() Lapse Parameter Options ..................................... 145
Table 17. Program Tasks............................................................................. 152
Table 18. Pipeline Mode Task Priorities ..................................................... 153
Table 19. Program Timing Instructions ...................................................... 154
Table 20. Rules for Names .......................................................................... 159
Table 21. Binary Conditions of TRUE and FALSE .................................... 165
Table 22. Logical Expression Examples ..................................................... 165
Table 23. Data Process Abbreviations ........................................................ 168
Table 24. CRBasic Example. Array Assigned Expression: Sum
Columns and Rows .............................................................................. 190
25
Table of Contents
Table 25. CRBasic Example. Array Assigned Expression: Transpose
an Array ............................................................................................... 190
Table 26. CRBasic Example. Array Assigned Expression: Comparison /
Boolean Evaluation .............................................................................. 191
Table 27. CRBasic Example. Array Assigned Expression: Fill Array
Dimension ............................................................................................ 192
Table 28. FieldCal() Codes ......................................................................... 212
Table 29. Calibration Report for Relative Humidity Sensor ....................... 214
Table 30. Calibration Report for Salinity Sensor ........................................ 216
Table 31. Calibration Report for Flow Meter .............................................. 218
Table 32. Calibration Report for Water Content Sensor ............................. 221
Table 33. Summary of Analog Voltage Measurement Rates ...................... 230
Table 34. Parameters for Analog Burst Mode (601 to 2000 Hz)................. 234
Table 35. PRTCalc() Type-Code-1 Sensor ................................................. 236
Table 36. PRTCalc() Type-Code-2 Sensor ................................................. 237
Table 37. PRTCalc() Type-Code-3 Sensor ................................................. 237
Table 38. PRTCalc() Type-Code-4 Sensor ................................................. 237
Table 39. PRTCalc() Type-Code-5 Sensor ................................................. 238
Table 40. PRTCalc() Type-Code-6 Sensor ................................................. 238
Table 41. ASCII / ANSI Equivalents .......................................................... 245
Table 42. CR1000 Serial Ports .................................................................... 247
Table 43. SDI-12 Commands for Transparent Mode .................................. 269
Table 44. SDI-12 Sensor Setup CRBasic Example — Results ................... 281
Table 45. Example Power Usage Profile for a Network of SDI-12
Probes................................................................................................... 282
Table 46. String Operators .......................................................................... 283
Table 47. String Concatenation Examples .................................................. 284
Table 48. String NULL Character Examples .............................................. 285
Table 49. Extracting String Characters ....................................................... 286
Table 50. Use of ASCII / ANSII Codes Examples...................................... 287
Table 51. Formatting Strings Examples ...................................................... 287
Table 52. Formatting Hexadecimal Variables — Examples ....................... 288
Table 53. WindVector() OutputOpt Options ............................................... 296
Table 54. CRBasic Parameters Varying Measurement Sequence and
Timing .................................................................................................. 307
Table 55. Analog Voltage Input Ranges and Options ................................. 309
Table 56. Analog-Voltage Measurement Accuracy1 ................................... 313
Table 57. Analog-Voltage Measurement Offsets ........................................ 313
Table 58. Analog-Voltage Measurement Resolution .................................. 313
Table 59. Analog Measurement Integration ................................................ 316
Table 60. Ac Noise Rejection on Small Signals1 ........................................ 317
Table 61. Ac Noise Rejection on Large Signals1 ........................................ 317
Table 62. CRBasic Measurement Settling Times ........................................ 318
Table 63. First Six Values of Settling-Time Data ....................................... 321
Table 64. Range-Code Option C Over-Voltages ......................................... 322
Table 65. Offset Voltage Compensation Options........................................ 325
Table 66. Limits of Error for Thermocouple Wire (Reference Junction
at 0°C) .................................................................................................. 331
Table 67. Voltage Range for Maximum Thermocouple Resolution ........... 331
Table 68. Limits of Error on CR1000 Thermocouple Polynomials ............ 334
Table 69. Reference-Temperature Compensation Range and Error ............ 335
Table 70. Thermocouple Error Examples ................................................... 336
26
Table of Contents
Table 71. Resistive-Bridge Circuits with Voltage Excitation ..................... 339
Table 72. Ratiometric-Resistance Measurement Accuracy......................... 342
Table 73. StrainCalc() Instruction Equations .............................................. 343
Table 74. Auto Calibration Gains and Offsets ............................................ 346
Table 75. Calibrate() Instruction Results .................................................... 347
Table 76. Pulse Measurements:, Terminals and Programming ................... 351
Table 77. Example. E for a 10 Hz input signal ........................................... 354
Table 78. Frequency Resolution Comparison ............................................. 354
Table 79. Switch Closures and Open Collectors on P Terminals ................ 357
Table 80. Switch Closures and Open Collectors on C Terminals ............... 357
Table 81. Three Specifications Differing Between P and C Terminals ...... 358
Table 82. 7LPH&RQVWDQWVIJ ...................................................................... 359
Table 83. Low-Level Ac Amplitude and Maximum Measured
Frequency............................................................................................. 360
Table 84. CR1000 Memory Allocation ....................................................... 371
Table 85. CR1000 Main Memory ............................................................... 373
Table 86. Memory Drives ........................................................................... 374
Table 87. Memory Card States.................................................................... 377
Table 88. TableFile() Instruction Data-File Formats .................................. 378
Table 89. File-Control Functions ................................................................ 382
Table 90. CR1000 File Attributes ............................................................... 383
Table 91. Data-Preserve Options ................................................................ 386
Table 92. Powerup.ini Commands and Applications .................................. 388
Table 93. Powerup.ini Example. Code Format and Syntax......................... 388
Table 94. Powerup.ini Example. Run Program on Power-up ..................... 388
Table 95. Powerup.ini Example. Format the USR: Drive ........................... 389
Table 96. Powerup.ini Example. Send OS on Power-up ............................. 389
Table 97. Powerup.ini Example. Run Program from USB: Drive .............. 389
Table 98. Powerup.ini Example. Run Program Always, Erase Data .......... 389
Table 99. Powerup.ini Example. Run Program Now, Erase Data ............... 389
Table 100. File System Error Codes ........................................................... 390
Table 101. PakBus Leaf-Node and Router Device Configuration .............. 395
Table 102. PakBus Link-Performance Gage ............................................... 398
Table 103. PakBus-LAN Example Datalogger-Communication Settings .. 403
Table 104. Router Port Numbers................................................................. 405
Table 105. DNP3 Implementation — Data Types Required to Store
Data in Public Tables for Object Groups ............................................. 409
Table 106. Modbus to Campbell Scientific Equivalents ............................. 412
Table 107. CRBasic Ports, Flags, Variables, and, Modbus Registers ......... 414
Table 108. Supported Modbus Function Codes .......................................... 415
Table 109. API Commands, Parameters, and Arguments ........................... 425
Table 110. BrowseSymbols API Command Parameters ............................. 427
Table 111. BrowseSymbols API Command Response ............................... 428
Table 112. DataQuery API Command Parameters...................................... 431
Table 113. SetValueEx API Command Parameters .................................... 437
Table 114. SetValue API Command Response ........................................... 437
Table 115. ClockSet API Command Parameters ........................................ 439
Table 116. ClockSet API Command Response ........................................... 439
Table 117. ClockCheck API Command Parameters ................................... 440
Table 118. ClockCheck API Command Response ...................................... 441
Table 119. Curl HTTPPut Request Parameters ........................................... 442
Table 120. FileControl API Command Parameters ..................................... 444
Table 121. FileControl API Command Response ....................................... 445
27
Table of Contents
Table 122. ListFiles API Command Parameters ......................................... 446
Table 123. ListFiles API Command Response............................................ 446
Table 124. NewestFile API Command Parameters ..................................... 450
Table 125. Special Keyboard-Display Key Functions ................................ 451
Table 126. Typical Gzip File Compression Results .................................... 465
Table 127. Internal Lithium-Battery Specifications .................................... 474
Table 128. Math Expressions and CRBasic Results.................................... 483
Table 129. Variable and Final-Memory Data Types with NAN and ±INF . 484
Table 130. Warning Message Examples ..................................................... 486
Table 131. CommsMemFree(1) Defaults and Use Example, TLS Not
Active ................................................................................................... 492
Table 132. CommsMemFree(1) Defaults and Use Example, TLS Active .. 492
Table 133. CR1000 Terminal Commands ................................................... 502
Table 134. Log Locations............................................................................ 504
Table 135. Program Send Command .......................................................... 524
Table 136. Arithmetic Operators ................................................................. 563
Table 137. Compound-Assignment Operators ............................................ 565
Table 138. Derived Trigonometric Functions ............................................. 568
Table 139. String Operations ...................................................................... 574
Table 140. Asynchronous-Port Baud Rates................................................. 588
Table 141. Status/Setting/DTI: Access Points............................................. 603
Table 142. Status/Settings/DTI: Directories................................................ 604
Table 143. Status/Settings/DTI: Frequently Used ....................................... 604
Table 144. Status/Settings/DTI: Alphabetical Listing of Keywords ........... 605
Table 145. Status/Settings/DTI: Status Table Entries on CR1000KD
Keyboard Display ................................................................................ 606
Table 146. Status/Settings/DTI: Settings (General) on CR1000KD
Keyboard Display ................................................................................ 606
Table 147. Status/Settings/DTI: Settings (comport) on CR1000KD
Keyboard Display ................................................................................ 607
Table 148. Status/Settings/DTI: Settings (TCP/IP) on CR1000KD
Keyboard Display ................................................................................ 607
Table 149. Status/Settings/DTI: Settings Only in Settings Editor ............... 607
Table 150. Status/Settings/DTI: Data Table Information Table (DTI)
Keywords ............................................................................................. 607
Table 151. Status/Settings/DTI: Auto-Calibration ...................................... 608
Table 152. Status/Settings/DTI: Communications, General........................ 608
Table 153. Status/Settings/DTI: Communications, PakBus ........................ 608
Table 154. Status/Settings/DTI: Communications, TCP_IP I ..................... 608
Table 155. Status/Settings/DTI: Communications, TCP_IP II .................... 608
Table 156. Status/Settings/DTI: Communications, TCP_IP III .................. 609
Table 157. Status/Settings/DTI: CRBasic Program I .................................. 609
Table 158. Status/Settings/DTI: CRBasic Program II ................................. 609
Table 159. Status/Settings/DTI: Data .......................................................... 609
Table 160. Status/Settings/DTI: Memory.................................................... 609
Table 161. Status/Settings/DTI: Miscellaneous .......................................... 609
Table 162. Status/Settings/DTI: Obsolete ................................................... 609
Table 163. Status/Settings/DTI: OS and Hardware Versioning .................. 610
Table 164. Status/Settings/DTI: Power Monitors........................................ 610
Table 165. Status/Settings/DTI: Security .................................................... 610
Table 166. Status/Settings/DTI: Signatures ................................................ 610
Table 167. Status/Settings/DTI: B............................................................... 611
28
Table of Contents
Table 168. Baudrate() Array, Keywords, and Default Settings................... 611
Table 169. Beacon() Array, Keywords, and Default Settings ..................... 612
Table 170. Status/Settings/DTI: C .............................................................. 612
Table 171. Status/Settings/DTI: D .............................................................. 615
Table 172. Status/Settings/DTI: E ............................................................... 616
Table 173. Status/Settings/DTI: F ............................................................... 616
Table 174. Status/Settings/DTI: H .............................................................. 617
Table 175. Status/Settings/DTI: I ................................................................ 617
Table 176. Status/Settings/DTI: L ............................................................... 619
Table 177. Status/Settings/DTI: M.............................................................. 620
Table 178. Status/Settings/DTI: N .............................................................. 622
Table 179. Status/Settings/DTI: O .............................................................. 622
Table 180. Status/Settings/DTI: P ............................................................... 623
Table 181. Status/Settings/DTI: R .............................................................. 626
Table 182. Status/Settings/DTI: S ............................................................... 627
Table 183. Status/Settings/DTI: T ............................................................... 629
Table 184. Status/Settings/DTI: U .............................................................. 631
Table 185. Status/Settings/DTI: V .............................................................. 631
Table 186. Status/Settings/DTI: W ............................................................. 632
Table 187. CS I/O Pin Description.............................................................. 633
Table 188. CR1000 RS-232 Pin-Out........................................................... 634
Table 189. Standard Null-Modem Cable or Adapter-Pin Connections ....... 635
Table 190. Decimal and hexadecimal Codes and Characters Used with
CR1000 Tools ...................................................................................... 637
Table 191. FP2 Data-Format Bit Descriptions ............................................ 641
Table 192. FP2 Decimal-Locater Bits ......................................................... 641
Table 193. Endianness in Campbell Scientific Instruments ........................ 643
Table 194. Dataloggers ............................................................................... 645
Table 195. Analog-Input Modules .............................................................. 646
Table 196. Pulse-Input Modules ................................................................. 646
Table 197. Serial I/O Modules List ............................................................. 646
Table 198. Vibrating-Wire Input Modules .................................................. 647
Table 199. Resistive Bridge TIM1 Modules ................................................ 647
Table 200. Voltage Divider Modules .......................................................... 647
Table 201. Current-Shunt Modules ............................................................. 647
Table 202. Transient Voltage Suppressors .................................................. 648
Table 203. Terminal-Strip Covers ............................................................... 648
Table 204. Digital I/O Modules .................................................................. 648
Table 205. Continuous-Analog-Output (CAO) Modules ............................ 649
Table 206. Relay-Drivers — Products ........................................................ 649
Table 207. Current-Excitation Modules ...................................................... 649
Table 208. Wired Sensor Types .................................................................. 650
Table 209. Wireless Sensor Modules .......................................................... 650
Table 210. Sensors Types Available for Connection to CWS900 .............. 651
Table 211. Datalogger / Keyboard Display Availability and
Compatibility1 ...................................................................................... 651
Table 212. Hardwire, Single-Connection Comms Devices ......................... 652
Table 213. Hardwire, Networking Devices ................................................. 652
Table 214. TCP/IP Links............................................................................. 652
Table 215. Telephone Modems ................................................................... 652
Table 216. Private-Network Radios ............................................................ 653
Table 217. Satellite Transceivers ................................................................ 653
Table 218. Mass-Storage Devices ............................................................... 653
29
Table of Contents
Table 219. CF-Card Storage Module .......................................................... 653
Table 220. Starter Software ......................................................................... 654
Table 221. Datalogger Support Software .................................................... 655
Table 222. LoggerNet Suite1,2 ..................................................................... 655
Table 223. Software Tools .......................................................................... 656
Table 224. Software Development Kits ...................................................... 656
Table 225. Battery / Regulator Combinations ............................................. 657
Table 226. Batteries .................................................................................... 658
Table 227. Regulators ................................................................................. 658
Table 228. Primary Power Sources ............................................................. 658
Table 229. 24 Vdc Power Supply Kits ........................................................ 659
Table 230. Enclosures — Products ............................................................. 659
Table 231. Prewired Enclosures .................................................................. 659
Table 232. Tripods, Towers, and Mounts.................................................... 659
Table 233. Protection from Moisture — Products ...................................... 660
List of CRBasic Examples
CRBasic Example 1. Simple Default.cr1 File to Control SW12
Terminal ............................................................................................... 116
CRBasic Example 2. Inserting Comments .................................................. 126
CRBasic Example 3. Data Type Declarations ............................................. 133
CRBasic Example 4. Using Variable Array Dimension Indices ................. 134
CRBasic Example 5. Flag Declaration and Use .......................................... 135
CRBasic Example 6. Using a Variable Array in Calculations .................... 136
CRBasic Example 7. Initializing Variables ................................................. 137
CRBasic Example 8. Using the Const Declaration ..................................... 138
CRBasic Example 9. Load binary information into a variable .................... 139
CRBasic Example 10. Definition and Use of a Data Table......................... 142
CRBasic Example 11. Use of the Disable Variable .................................... 146
CRBasic Example 12. Using an 'Include' File ............................................. 149
CRBasic Example 13. 'Include' File to Control SW12 Terminal. 150
CRBasic Example 14. BeginProg / Scan() / NextScan / EndProg Syntax .. 155
CRBasic Example 15. Measurement Instruction Syntax............................. 159
CRBasic Example 16. Use of Move() to Conserve Code Space ................. 162
CRBasic Example 17. Use of Variable Arrays to Conserve Code Space.... 162
CRBasic Example 18. Conversion of FLOAT / LONG to Boolean ............ 162
CRBasic Example 19. Evaluation of Integers ............................................. 163
CRBasic Example 20. Constants to LONGs or FLOATs............................ 163
CRBasic Example 21. String and Variable Concatenation ......................... 166
CRBasic Example 22. BeginProg / Scan / NextScan / EndProg Syntax ..... 169
CRBasic Example 23. Conditional Output .................................................. 170
CRBasic Example 24. Groundwater Pump Test ......................................... 172
CRBasic Example 25. Miscellaneous Program Features ............................ 174
CRBasic Example 26. Scaling Array .......................................................... 177
CRBasic Example 27. Program Signatures ................................................. 178
CRBasic Example 28. Use of Multiple Scans ............................................. 179
CRBasic Example 29. Conditional Code .................................................... 181
CRBasic Example 30. Custom Menus ........................................................ 185
CRBasic Example 31. Loading Large Data Sets ......................................... 188
CRBasic Example 32. Using TrigVar to Trigger Data Storage................... 196
CRBasic Example 33. Two Data-Output Intervals in One Data Table ....... 197
30
Table of Contents
CRBasic Example 34. Programming with Bool8 and a Bit-Shift
Operator ............................................................................................... 200
CRBasic Example 35. NSEC — One Element Time Array ........................ 203
CRBasic Example 36. NSEC — Two Element Time Array ....................... 203
CRBasic Example 37. NSEC — Seven and Nine Element Time Arrays .... 204
CRBasic Example 38. NSEC —Convert Timestamp to Universal Time .... 205
CRBasic Example 39. Using TableFile() with Option 64 with CF Card .... 207
CRBasic Example 40. FieldCal() Zero ....................................................... 215
CRBasic Example 41. FieldCal() Offset ..................................................... 217
CRBasic Example 42. FieldCal() Two-Point Slope and Offset .................. 219
CRBasic Example 43. FieldCal() Multiplier ............................................... 221
CRBasic Example 44. FieldCalStrain() Calibration .................................... 225
CRBasic Example 45. Measurement with Excitation and Delay ................ 228
CRBasic Example 46. Measuring VoltSE() at 1 Hz.................................... 230
CRBasic Example 47. Measuring VoltSE() at 100 Hz................................ 231
CRBasic Example 48. Measuring VoltSE() at 200 Hz................................ 231
CRBasic Example 49. Measuring VoltSE() at 2000 Hz.............................. 233
CRBasic Example 50. PT100 in Four-Wire Half-Bridge ............................ 240
CRBasic Example 51. PT100 in Three-wire Half-bridge............................ 242
CRBasic Example 52. PT100 in Four-Wire Full-Bridge ............................ 244
CRBasic Example 53. Receiving an RS-232 String .................................... 255
CRBasic Example 54. Measure Sensors / Send RS-232 Data ..................... 260
CRBasic Example 55. Using SDI12Sensor() to Test Cv Command ........... 276
CRBasic Example 56. Using Alternate Concurrent Command (aC) ........... 277
CRBasic Example 57. Using an SDI-12 Extended Command .................... 279
CRBasic Example 58. SDI-12 Sensor Setup ............................................... 280
CRBasic Example 59. Concatenation of Numbers and Strings................... 284
CRBasic Example 60. Formatting Strings .................................................. 287
CRBasic Example 61. Subroutine with Global and Local Variables .......... 289
CRBasic Example 62. Custom Web Page HTML....................................... 293
CRBasic Example 63. Time Stamping with System Time .......................... 304
CRBasic Example 64. Measuring Settling Time......................................... 320
CRBasic Example 65. Four-Wire Full-Bridge Measurement and
Processing ............................................................................................ 341
CRBasic Example 66. Implementation of DNP3 ........................................ 410
CRBasic Example 67. Concatenating Modbus Long Variables .................. 416
CRBasic Example 68. Custom Web Page HTML....................................... 421
CRBasic Example 69. Using NAN to Filter Data ....................................... 485
CRBasic Example 70. Using Bit-Shift Operators ....................................... 565
31
1.
Introduction
1.1
HELLO
Whether in extreme cold in Antarctica, scorching heat in Death Valley, salt spray
from the Pacific, micro-gravity in space, or the harsh environment of your office,
Campbell Scientific dataloggers support research and operations all over the
world. Our customers work a spectrum of applications, from those more complex
than any of us imagined, to those simpler than any of us thought practical. The
limits of the CR1000 are defined by our customers. Our intent with this operator's
manual is to guide you to the tools you need to explore the limits of your
application.
You can take advantage of the advanced CR1000 analog and digital measurement
features by spending a few minutes working through the System Quickstart (p. 41)
and the System Overview (p. 61). For more demanding applications, the remainder
of the manual and other Campbell Scientific publications are available. If you are
programming with CRBasic, you will need the extensive help available with the
CRBasic Editor software. Formal CR1000 training is also available from
Campbell Scientific.
This manual is organized to take you progressively deeper into the complexity of
CR1000 functions. You may not find it necessary to progress beyond the System
Quickstart (p. 41) or System Overview (p. 61) sections. Quickstart Tutorial (p. 41) gives
a cursory view of CR1000 data-acquisition and walks you through a first attempt
at data-acquisition. System Overview (p. 61) reviews salient topics that are covered
in-depth in subsequent sections and appendices.
Review the exhaustive table of contents to learn how the manual is organized,
and, when looking for a topic, use the index and PDF reader search.
More in-depth study requires other Campbell Scientific publications, most of
which are available on-line at www.campbellsci.com. Generally, if a particular
feature of the CR1000 requires a peripheral hardware device, more information is
available in the manual written for that device.
If you are unable to find the information you need, need assistance with ordering,
or just wish to speak with one of our many product experts about your application,
please call us at (435) 227-9100 or email [email protected] In earlier
days, Campbell Scientific dataloggers greeted our customers with a cheery
HELLO at the flip of the ON switch. While the user interface of the CR1000
datalogger has advanced beyond those simpler days, you can still hear the cheery
HELLO echoed in the voices you hear at Campbell Scientific.
1.2
Typography
The following type faces are used throughout the CR1000 Operator's Manual.
Type color other than black on white does not appear in printed versions of the
manual:
x
x
Underscore — Information specifically flagged as unverified. Usually found
only in a draft or a preliminary released version.
Capitalization — beginning of sentences, phrases, titles, names, Campbell
Scientific product model numbers.
33
Section 1. Introduction
x
x
x
x
x
x
x
Bold — CRBasic instructions within the body text, input commands, output
responses, GUI commands, text on product labels, names of data tables.
Page numbers — in the PDF version of the manual, hyperlink to the page
represented by the number.
Italic — glossary entries and titles of publications, software, sections, tables,
figures, and examples.
Bold italic — CRBasic instruction parameters and arguments within the body
text.
Blue — CRBasic instructions when set on a dedicated line.
Teal italic — CRBasic program comments.
CRBasic code, input commands, and output responses when set apart on
dedicated lines or in program examples, as follows:
Lucida Sans Typewriter
1.3
Capturing CRBasic Code
Many examples of CRBasic code are found throughout this manual. The manual
is designed to make using this code as easy a possible. Keep the following in
mind when copying code from this manual into CRBasic Editor:
If an example crosses pages, select and copy only the contents of one page at a
time. Doing so will help avoid unwanted characters that may originate from page
headings, page numbers, and hidden characters.
1.4
Release Notes
Preliminary Version 3/26/15 for OS v.28:
Reviewers
If feasible, please wait until a future preliminary version is available, perhaps in
June of 2015, for a comprehensive review.
Readers
If any information in this manual, which is preliminary to address OS v. 28
changes, is mission critical, please consult a Campbell Scientific application
engineer.
Primary changes since Version 5/13 are addition of the Precautions (p. 7) section
and completion of about 90% of appendix Status, Settings and Data Table
Information (p. 603) to reflect the major changes to the status, settings, and data
table information registers introduced in OS v. 28.
The remaining sections, from Installation (p. 99) through the appendix Supporting
Product Lists (p. 645), are slated for numerous updates. The following topics are
among those yet to be added or updated:
Analog measurement
Arrays
CDM
Constant table
Data types
DNP3 (major revision)
Function() instruction
Keyboard display
Modbus
34
Section 1. Introduction
NewFile() instruction
Operating system management
Period averaging
Precision of variables
Programming
Route() instruction
Security
Skipped records
Subroutines
SW12 and 12V terminals
Task sequencer
Terminal mode
Time and clock
Troubleshooting
Watchdog resets
35
2.
Cautionary Statements
x
x
DANGER: Fire, explosion, and severe-burn hazard. Misuse or improper
installation of the internal lithium battery can cause severe injury. Do not
recharge, disassemble, heat above 100 °C (212 °F), solder directly to the cell,
incinerate, or expose contents to water. Dispose of spent lithium batteries
properly.
WARNING:
o
o
o
x
x
Protect from over-voltage
Protect from water
Protect from ESD (p. 105)
CAUTION: Disuse accelerates depletion of the internal battery, which backs
up several functions. The internal battery will be depleted in three years or
less if a CR1000 is left on the shelf. When the CR1000 is continuously used,
the internal battery may last up to 10 or more years. See section Internal
Battery — Details (p. 94) for more information.
IMPORTANT: Maintain a level of calibration appropriate to the application.
Campbell Scientific recommends factory recalibration of the CR1000 every
three years.
37
3.
Initial Inspection
x
Check the Ships With tab at http://www.campbellsci.com/CR1000 for a list
of items shipped with the CR1000. Among other things, the following are
provided for immediate use:
o
o
o
o
o
Screwdriver to connect wires to terminals
Type-T thermocouple for use in the System Quickstart (p. 41) tutorial
A datalogger program pre-loaded into the CR1000 that measures powersupply voltage and wiring-panel temperature.
A serial communication cable to connect the CR1000 to a PC
A ResourceDVD that contains product manuals and the following starter
software:
Short Cut
PC200W
DevConfig
x
x
x
Upon receipt of the CR1000, inspect the packaging and contents for damage.
File damage claims with the shipping company.
Immediately check package contents. Thoroughly check all packaging
material for product that may be concealed. Check model numbers, part
numbers, and product descriptions against the shipping documents. Model or
part numbers are found on each product. On cabled items, the number is
often found at the end of the cable that connects to the measurement device.
The Campbell Scientific number may differ from the part or model number
printed on the sensor by the sensor vendor. Ensure that the expected lengths
of cables were received. Contact Campbell Scientific immediately if there
are any discrepancies.
Check the operating system version in the CR1000 as outlined in the section
Sending the Operating System (OS) (p. 117), and update as needed.
39
4.
System Quickstart
Reading List
‡Quickstart (p. 41)
‡Specifications (p. 97)
‡Installation (p. 99)
‡Operation (p. 303)
This tutorial presents an introduction to CR1000 data acquisition and a practical
programming and data retrieval exercise.
4.1
Data-Acquisition Systems — Quickstart
Related Topics:
‡Data-Acquisition Systems — Quickstart (p. 41)
‡Data-Acquisition Systems — Overview (p. 62)
Acquiring data with a Campbell Scientific datalogger is a fairly defined procedure
involving the use of electronic sensor technology, the CR1000 datalogger, a
telecommunication link, and datalogger support software (p. 512)
A CR1000 is only one part of a data-acquisition system. To acquire good data,
suitable sensors and a reliable data-retrieval method are required. A failure in any
part of the system can lead to "bad" data or no data. A typical data-acquisition
system is conceptualized in figure Data-Acquisition System Components (p. 42)
Following is a list of typical system components:
x
x
x
x
x
x
Sensors (p. 42) — Electronic sensors convert the state of a phenomenon to an
electrical signal.
Datalogger (p. 43) — The CR1000 measures electrical signals or reads serial
characters. It converts the measurement or reading to engineering units,
performs calculations, and reduces data to statistical values. Data are stored
in memory to await transfer to a PC by way of an external storage device or a
telecommunication link.
Data Retrieval and Telecommunications (p. 45) — Data are copied (not moved)
from the CR1000, usually to a PC, by one or more methods using datalogger
support software. Most of these telecommunication options are bi-directional
and so allow programs and settings to be sent to the CR1000.
Datalogger Support Software (p. 46) — Software retrieves data and sends
programs and settings. The software manages the telecommunication link
and has options for data display.
Programmable Logic Control (p. 74) — Some data-acquisition systems require
the control of external devices to facilitate a measurement or to control a
device based on measurements. The CR1000 is adept at programmable logic
control. Unfortunately, there is little discussion of these capabilities in this
manual. Consult CRBasic Editor Help (p. 125) or a Campbell Scientific
Application Engineer for more information.
Measurement and Control Peripherals (p. 85) — Some system requirements
exceed the standard input or output compliment of the CR1000. Most of
these requirements can be met by addition of input and output expansion
modules.
41
Section 4. System Quickstart
Figure 1. Data-Acquisition System Components
4.2
Sensors — Quickstart
Related Topics:
‡Sensors — Quickstart (p. 42)
‡Measurements — Overview (p. 62)
‡Measurements — Details (p. 303)
‡Sensors — Lists (p. 649)
Sensors transduce phenomena into measurable electrical forms by modulating
voltage, current, resistance, status, or pulse output signals. Suitable sensors do
this accurately and precisely (p. 533). Smart sensors have internal measurement and
processing components and simply output a digital value in binary, hexadecimal,
or ASCII character form. The CR1000, sometimes with the assistance of various
peripheral devices, can measure or read nearly all electronic sensor output types.
Sensor types supported include:
x
Analog
o
o
o
o
x
Pulse
o
o
o
x
x
x
High frequency
Switch closure
Low-level ac
Period average
Vibrating wire
Smart sensors
o
o
42
Voltage
Current
Thermocouples
Resistive bridges
SDI-12
RS-232
Section 4. System Quickstart
o
o
o
Modbus
DNP3
RS-485
Refer to the appendix Sensors — Lists (p. 649) for a list of specific sensors available
from Campbell Scientific. A library of sensor manuals and application notes are
available at www.campbellsci.com to assist in measuring many sensor types. The
previous list of supported sensors is not necessarily comprehensive. Consult with
a Campbell Scientific application engineer for assistance in measuring unfamiliar
sensors.
4.3
Datalogger — Quickstart
Related Topics:
‡Datalogger — Quickstart (p. 43)
‡Datalogger — Overview (p. 75)
‡Dataloggers — List (p. 645)
The CR1000 can measure almost any sensor with an electrical response. The
CR1000 measures electrical signals and converts the measurement to engineering
units, performs calculations and reduces data to statistical values. Most
applications do not require that every measurement be stored but rather combined
with other measurements in statistical or computational summaries. The CR1000
will store data in memory to await transfer to the PC with an external storage
devices or telecommunications.
CR1000 electronics are protected in a sealed stainless steel shell. This design
makes the CR1000 economical, small, and very rugged.
4.3.1.1 Wiring Panel — Quickstart
Related Topics
‡Wiring Panel — Quickstart (p. 43)
‡Wiring Panel — Overview (p. 76)
‡Measurement and Control Peripherals (p. 366)
As shown in figure Wiring Panel (p. 44), the CR1000 wiring panel provides
terminals for connecting sensors, power, and communication devices. Surge
protection is incorporated internally in most wiring panel connectors.
43
Section 4. System Quickstart
Figure 2. Wiring Panel
4.4
Power Supplies — Quickstart
Related Topics:
‡3RZHU6XSSOLHV— Specifications
‡Power Supplies — Quickstart (p. 44)
‡Power Supplies — Overview (p. 85)
‡Power Supplies — Details (p. 100)
‡Power Supplies — Products (p. 657)
‡Power Sources (p. 101)
‡Troubleshooting — Power Supplies (p. 494)
The CR1000 requires a power supply. Be sure that any power supply components
match the specifications of the device to which they are connected. When
connecting power, first switch off the power supply, then make the connection
before switching the supply on.
The CR1000 is operable with power from 9.6 to 16 Vdc applied at the POWER
IN terminals of the green connector on the face of the wiring panel.
External power connects through the green POWER IN connector on the face of
the CR1000. The positive power lead connects to 12V. The negative lead
44
Section 4. System Quickstart
connects to G. The connection is internally reverse-polarity protected.
The CR1000 is internally protected against accidental polarity reversal on the
power inputs.
4.4.1
Internal Battery — Quickstart
Related Topics:
‡Internal Battery — Quickstart (p. 45)
‡Internal Battery — Details (p. 94)
Warning Misuse or improper installation of the internal lithium battery can
cause severe injury. Fire, explosion, and severe burns can result. Do not recharge,
disassemble, heat above 100 °C (212 °F), solder directly to the cell, incinerate, or
expose contents to water. Dispose of spent lithium batteries properly.
A lithium battery backs up the CR1000 clock, program, and memory.
4.5
Data Retrieval and Telecommunications — Quickstart
Related Topics:
‡Data Retrieval and Telecommunications — Quickstart (p. 45)
‡Data Retrieval and Telecommunications — Overview (p. 88)
‡Data Retrieval and Telecommunications — Details (p. 391)
‡Data Retrieval and Telecommunication Peripherals — Lists (p. 651)
If the CR1000 datalogger sits near a PC, direct-connect serial communication is
usually the best solution. In the field, direct serial, a data-storage device, can be
used during a site visit. A remote telecommunication option (or a combination of
options) allows you to collect data from your PC over long distances and gives
you the power to discover problems early.
A Campbell Scientific application engineer can help you make a shopping list for
any of these telecommunication options:
x
Standard
o
x
RS-232 serial
Options
o
o
o
o
o
o
o
Ethernet
CompactFlash, Mass Storage
Cellular, Telephone
iOS, Android
PDA
Multidrop, Fiber Optic
Radio, Satellite
Some telecommunication options can be combined.
45
Section 4. System Quickstart
4.6
Datalogger Support Software — Quickstart
Reading List:
‡Datalogger Support Software — Quickstart (p. 46)
‡Datalogger Support Software — Overview (p. 95)
‡Datalogger Support Software — Details (p. 450)
‡Datalogger Support Software — Lists (p. 654)
Datalogger support software are PC or Linux software available from Campbell
Scientific that facilitate communication between the computer and the CR1000.
A wide array of software are available, but this section focuses on the following:
x
x
x
Short Cut Program Generator for Windows (SCWin)
PC200W Datalogger Starter Software for Windows
LoggerLink Mobile Datalogger Starter software for iOS and Android
A CRBasic program must be loaded into the CR1000 to enable it to make
measurements, read sensors, and store data. Short Cut is used to write simple
CRBasic programs without the need to learn the CRBasic programming language.
Short Cut is an easy-to-use wizard that steps you through the program building
process.
After the CRBasic program is written, it is loaded onto the CR1000. Then, after
sufficient time has elapsed for measurements to be made and data to be stored,
data are retrieved to a computer. These functions are supported by PC200W and
LoggerLink Mobile.
Short Cut and PC200W are available at no charge at
www.campbellsci.com/downloads (http://www.campbellsci.com/downloads).
Note More information about software available from Campbell Scientific can be
found at www.campbellsci.com http://www.campbellsci.com. Please consult with
a Campbell Scientific application engineer for a software recommendation to fit a
specific application.
4.7
Tutorial: Measuring a Thermocouple
This tutorial illustrates the primary functions of the CR1000. The exercise
highlights the following:
x
x
x
x
x
x
4.7.1
Attaching a sensor to the datalogger
Creating a program for the CR1000 to measure the sensor
Making a simple measurement
Storing measurement data
Collecting data from the CR1000 with a PC
Viewing real-time and historical data from the CR1000
What You Will Need
The following items are used in this exercise. If you do not have all of these
items, you can provide suitable substitutes. If you have questions about
compatible power supplies or serial cables, please consult a Campbell Scientific
application engineer.
46
Section 4. System Quickstart
x
x
x
x
x
x
CR1000 datalogger
Power supply with an output between 10 to 16 Vdc
Thermocouple, 4 to 5 inches long, which is shipped with the CR1000
Personal computer (PC) with an available nine-pin RS-232 serial port, or with
a USB port and a USB-to-RS-232 adapter
Nine-pin female to nine-pin male RS-232 cable, which is shipped with the
CR1000
PC200W software, which is available on the Campbell Scientific resource
DVD or thumb drive, or at www.campbellsci.com.
Note If the CR1000 datalogger is connected to the PC during normal operations,
use the Campbell Scientific SC32B interface to provide optical isolation through
the CS I/O port. Doing so protects low-level analog measurements from
grounding disturbances.
4.7.2
Hardware Setup
Note The thermocouple is attached to the CR1000 later in this exercise.
4.7.2.1 External Power Supply
With reference to the figure Power and Serial Communication Connections (p. 48),
proceed as follows:
1. Remove the green power connector from the CR1000 wiring panel.
2. Switch off the power supply.
3. Connect the positive lead of the power supply to the 12V terminal of the green
power connector. Connect the negative (ground) lead of the power supply to
the G terminal of the green connector.
4. After confirming the power supply connections have the correct polarity, insert
the green power connector into its receptacle on the CR1000 wiring panel.
5. Connect the serial cable between the RS-232 port on the CR1000 and the RS232 port on the PC.
6. Switch the power supply on.
47
Section 4. System Quickstart
Figure 3. Power and Serial Communication Connections
4.7.3
PC200W Software Setup
1. Install PC200W software onto the PC. Follow on-screen prompts during the
installation process. Use the default folders.
2. Open PC200W. Your PC should display a window similar to figure PC200W
Main Window (p. 49). When PC200W is first run, the EZSetup Wizard will run
automatically in a new window. This will configure the software to
communicate with the CR1000 datalogger. The table PC200W EZSetup
Wizard Example Selections (p. 49) indicates what information to enter on each
screen of the wizard. Click Next at the lower portion of the window to
advance.
See More! A video tutorial is available at
www.youtube.com/playlist?list=PL9E364A63D4A3520A&feature=plcp. Other
video tutorials are available at www.campbellsci.com/videos.
After exiting the wizard, the main PC200W window becomes visible. This
window has several tabs. The Clock/Program tab displays information on the
currently selected CR1000 with clock and program functions. Monitor Data and
Collect Data tabs are also available. Icons across the top of the window access
additional functions.
48
Section 4. System Quickstart
Figure 4. PC200W Main Window
Table 1. PC200W EZSetup Wizard Example Selections
Start the wizard to follow table entries.
Screen Name
Introduction
Datalogger Type and Name
Information Needed
Provides an introduction to the EZSetup Wizard along with
instructions on how to navigate through the wizard.
Select the CR1000 from the list box.
Accept the default name of "CR1000."
Select the correct PC COM port for the serial connection.
Typically, this will be COM1. Other COM numbers are
possible, especially when using a USB cable.
Leave COM Port Communication Delay at 00 seconds.
COM Port Selection
Datalogger Settings
Note When using USB serial cables, the COM number may
change if the cable is moved to a different USB port. This will
prevent data transfer between the software and CR1000. Should
this occur, simply move the cable back to the original port. If
this is not possible, close then reopen the PC200W software to
refresh the available COM ports. Click on Edit Datalogger
Setup and change the COM port to the new port number.
Configures how the CR1000 communicates with the PC.
For this tutorial, accept the default settings.
Datalogger Settings Security
For this tutorial, Security Code should be set to 0 and PakBus
Encryption Key should be left blank.
Communication Setup
Summary
Provides a summary of settings in previous screens. No changes
are needed for this tutorial. Press Finish to exit the wizard.
49
Section 4. System Quickstart
4.7.4
Write CRBasic Program with Short Cut
Short Cut objectives:
x
x
Create a program to measure the voltage of the CR1000 power supply,
temperature of the CR1000 wiring-panel, and ambient air temperature using a
thermocouple.
When program is downloaded to the CR1000, it takes samples once per
second and stores averages of these values at one-minute intervals.
See More A video tutorial is available at
www.youtube.com/playlist?list=PLCD0CAFEAD0390434&feature=plcp
http://www.youtube.com/playlist?list=PLCD0CAFEAD0390434&feature=plcp.
Other video resources are available at www.campbellsci.com/videos.
4.7.4.1 Procedure: (Short Cut Steps 1 to 5)
1. Click on the Short Cut icon in the upper-right corner of the PC200W window.
The icon resembles a clock face.
2. The Short Cut window is shown. Click New Program.
3. In the Datalogger Model drop-down list, select CR1000.
4. In the Scan Interval box, enter 1 and select Seconds in the drop-down list box.
Click Next.
Note The first time Short Cut is run, a prompt will appear asking for a choice of
ac noise rejection. Select 60 Hz for the United States and areas using 60 Hz ac
voltage. Select 50 Hz for most of Europe and areas that operate at 50 Hz.
A second prompt lists sensor support options. Campbell Scientific, Inc. (US) is
probably the best fit if you are outside Europe.
5. The next window displays Available Sensors and Devices. Expand the
Sensors folder by clicking on the symbol. This shows several sub-folders.
Expand the Temperature folder to view available sensors. Note that a wiring
panel temperature (PTemp_C in the Selected column) is selected by default.
50
Section 4. System Quickstart
Figure 5. Short Cut Temperature Sensor Folder
4.7.4.2 Procedure: (Short Cut Steps 6 to 7)
6. Double-click Type T (copper-constantan) Thermocouple to add it into the
Selected column. A dialog window is presented with several fields. By
immediately clicking OK, you accept default options that include selection of
1 sensor and PTemp_C as the reference temperature measurement.
Note BattV (battery voltage) and PTempC (wiring panel temperature) are
default measurements. During operation, battery and temperature should be
recorded at least daily to assist in monitoring system status.
7. At the left portion of the main Short Cut window, click Wiring Diagram.
Attach the physical type-T thermocouple to the CR1000 as shown in the
diagram. Click on 3. Sensors in the left portion of the window to return to the
sensor selection screen.
51
Section 4. System Quickstart
Figure 6. Short Cut Thermocouple Wiring
4.7.4.3 Procedure: (Short Cut Step 8)
Historical Note In the space-race era, measuring thermocouples in the field was
a complicated and cumbersome process incorporating a three-junction
thermocouple, a micro-voltmeter, a vacuum flask filled with an ice slurry, and a
thick reference book. One junction connected to the micro-voltmeter. Another sat
in the vacuum flask as a 0 °C reference. The third was inserted into the location of
the temperature of interest. When the microvolt measurement settled out, the
microvolt reading was recorded by hand. This value was then looked up on the
appropriate table in the reference book to determine the equivalent temperature.
Then along came Eric and Evan Campbell. Campbell Scientific designed the first
CR7 datalogger to make thermocouple measurements without the need for
vacuum flasks, reference books, or three junctions. Now, there's an idea!
Nowadays, a thermocouple need only consist of two wires of dissimilar metals,
such as copper and constantan, joined at one end. The joined end is the
measurement junction; the junction that is created when the two wires of
dissimilar metals are wired to CR1000 analog input terminals is the reference
junction.
When the two junctions are at different temperatures, a voltage proportional to the
temperature difference is induced in the wires. The thermocouple measurement
requires the reference-junction temperature to calculate the measurement-junction
temperature using proprietary algorithms in the CR1000 operating system.
52
Section 4. System Quickstart
8. Click Next to advance to the Outputs tab, which displays the list Selected
Sensors to the left and data storage tables to the right under Selected Outputs.
Figure 7. Short Cut Outputs Tab
4.7.4.4 Procedure: (Short Cut Steps 9 to 12)
9. Two output tables (1 Table1 and 2 Table2 tabs) are initially available. Both
tables have a Store Every field and a drop-down list from which to select the
time units. These are used to set the time intervals when data are stored.
10. Only one table is needed for this tutorial, so Table 2 can be removed. Click 2
Table2, then click Delete Table.
11. Change the name of the remaining table from Table1 to OneMin, and then
change the Store Every interval to 1 Minutes.
12. Add measurements to the table by selecting BattV under Selected Sensors,
and then clicking Average in the center column of buttons. Repeat this
procedure for PTemp_C and Temp_C.
53
Section 4. System Quickstart
Figure 8. Short Cut Outputs Tab
4.7.4.5 Procedure: (Short Cut Steps 13 to 14)
13. Click Finish to compile the program. Give the program the name
MyTemperature. A summary screen will appear showing the compiler
results. Any errors during compiling will be displayed.
Figure 9. Short Cut Compile Confirmation
54
Section 4. System Quickstart
14. Close this window by clicking on X in the upper right corner.
4.7.5
Send Program and Collect Data
PC200W Datalogger Support Software objectives:
x
x
x
Send the CRBasic program created by Short Cut in the previous procedure to
the CR1000.
Collect data from the CR1000.
Store the data on the PC.
4.7.5.1 Procedure: (PC200W Step 1)
1. From the PC200W Clock/Program tab, click on Connect button to establish
communications with the CR1000. When communications have been
established, the button will change to Disconnect.
Figure 10. PC200W Main Window
4.7.5.2 Procedure: (PC200W Steps 2 to 4)
2. Click Set Clock to synchronize the CR1000 clock with the computer clock.
3. Click Send Program.... A warning will appear that data on the datalogger will
be erased. Click Yes. A dialog box will open. Browse to the
C:\CampbellSci\SCWin folder. Select the MyTemperature.cr1 file. Click
Open. A status bar will appear while the program is sent to the CR1000
followed by a confirmation that the transfer was successful. Click OK to
close the confirmation.
4. After sending a program to the CR1000, a good practice is to monitor the
measurements to ensure they are reasonable. Select the Monitor Data tab.
The window now displays data found in the CR1000 Public table.
55
Section 4. System Quickstart
Figure 11. PC200W Monitor Data Tab – Public Table
4.7.5.3 Procedure: (PC200W Step 5)
5. To view the OneMin table, select an empty cell in the display area. Click
Add. In the Add Selection window Tables field, click on OneMin, then
click Paste. The OneMin table is now displayed.
56
Section 4. System Quickstart
Figure 12. PC200W Monitor Data Tab — Public and OneMin Tables
4.7.5.4 Procedure: (PC200W Step 6)
6. Click on the Collect Data tab and select data to be collected and the storage
location on the PC.
Figure 13. PC200W Collect Data Tab
57
Section 4. System Quickstart
4.7.5.5 Procedure: (PC200W Steps 7 to 10)
7. Click the OneMin box so a check mark appears in the box. Under What to
Collect, select New data from datalogger. This selects the data to be
collected.
8. Click on a table in the list to highlight it, then click Change Table's Output
File... to change the name of the destination file.
9. Click on Collect. A progress bar will appear as data are collected, followed by
a Collection Complete message. Click OK to continue.
10. To view data, click the
the View utility.
icon at the top of the PC200W window to open
Figure 14. PC200W View Data Utility
58
Section 4. System Quickstart
4.7.5.6 Procedure: (PC200W Steps 11 to 12)
11. Click on
to open a file for viewing. In the dialog box, select the
CR1000_OneMin.dat file and click Open.
12. The collected data are now shown.
Figure 15. PC200W View Data Table
4.7.5.7 Procedure: (PC200W Steps 13 to 14)
13. Click the heading of any data column. To display the data in that column in a
line graph, click the
icon.
14. Close the Graph and View windows, and then close the PC200W program.
59
Section 4. System Quickstart
Figure 16. PC200W View Line Graph
60
5.
System Overview
Reading List
‡Quickstart (p. 41)
‡Specifications (p. 97)
‡Installation (p. 99)
‡Operation (p. 303)
A Campbell Scientific data-acquisition system is made up of the following basic
components:
x
x
Sensors
Datalogger, which includes:
o
o
o
o
x
x
Clock
Measurement and control circuitry
Hardware and firmware to communicate with telecommunication devices
User-entered CRBasic program
Telecommunication link or external storage device
Datalogger support software (p. 512)
The figure Data-Acquisition Systems — Overview (p. 62) illustrates a common
CR1000-based data-acquisition system.
61
Section 5. System Overview
Figure 17. Data-Acquisition System — Overview
5.1
Measurements — Overview
Related Topics:
‡Sensors — Quickstart (p. 42)
‡Measurements — Overview (p. 62)
‡Measurements — Details (p. 303)
‡Sensors — Lists (p. 649)
62
Section 5. System Overview
Most electronic sensors, whether or not they are supplied by Campbell Scientific,
can be connected directly to the CR1000.
Manuals that discuss alternative input routes, such as external multiplexers,
peripheral measurement devices, or a wireless sensor network, can be found at
www.campbellsci.com/manuals (http://www.campbellsci.com/manuals). You can
also consult with a Campbell Scientific application engineer.
This section discusses direct sensor-to-datalogger connections and applicable
CRBasic programming to instruct the CR1000 how to make, process, and store
the measurements. The CR1000 wiring panel has terminals for the following
measurement inputs:
5.1.1
Time Keeping — Overview
Related Topics:
‡Time Keeping — Overview (p. 75)
‡Time Keeping — Details (p. 303)
Measurement of time is an essential function of the CR1000. Time measurement
with the on-board clock enables the CR1000 to attach time stamps to data,
measure the interval between events, and time the initiation of control functions.
5.1.2
Analog Measurements — Overview
Related Topics:
‡Analog Measurements — Overview (p. 63)
‡Analog Measurements — Details (p. 305)
Analog sensors output a continuous voltage or current signal that varies with the
phenomena measured. Sensors compatible with the CR1000 output a voltage.
Current output can be made compatible with a resistive shunt.
Sensor connection is to H/L] terminals configurable for differential (DIFF) or
single-ended (SE) inputs. For example, differential channel 1 is comprised of
terminals 1H and 1L, with 1H as high and 1L as low.
5.1.2.1 Voltage Measurements — Overview
Related Topicss:
‡9ROWDJH0HDVXUHPHQWV— Specifications
‡Voltage Measurements — Overview (p. 63)
‡Voltage Measurements — Details (p. 305)
x
x
Maximum input voltage range: r5000 mV
Measurement resolution range: 0.67 μV to 1333 μV
Single-ended and differential connections are illustrated in the figures Analog
Sensor Wired to Single-Ended Channel #1 (p. 64) and Analog Sensor Wired to
Differential Channel #1 (p. 64). Table Differential and Single-Ended Input
Terminals (p. 65) lists CR1000 analog-input channel termnal assignments.
Conceptually, analog-voltage sensors output two signals: high and low.
Sometimes, the low signal is simply sensor ground. A single-ended measurement
measures the high signal with reference to ground, with the low signal tied to
63
Section 5. System Overview
ground. A differential measurement measures the high signal with reference to
the low signal. Each configuration has a purpose, but the differential
configuration is usually preferred.
A differential configuration may significantly improve the voltage measurement.
Following are conditions the often indicate that a differential measurement should
be used:
x
x
Ground currents cause voltage drop between the sensor and the signal-ground
terminal. Currents >5 mA are usually considered undesirable. These
currents may result from resistive-bridge sensors using voltage excitation, but
these currents only flow when the voltage excitation is applied. Return
currents associated with voltage excitation cannot influence other singleended measurements of small voltage unless the same voltage-excitation
terminal is enabled during the unrelated measurements.
Measured voltage is less than 200 mV.
Figure 18. Analog Sensor Wired to Single-Ended Channel #1
Figure 19. Analog Sensor Wired to Differential Channel #1
64
Section 5. System Overview
Table 2. Differential and Single-Ended Input
Terminals
DIFF Terminals
SE Terminals
1H
1
1L
2
2H
3
2L
4
3H
5
3L
6
4H
7
4L
8
5H
9
5L
10
6H
11
6L
12
7H
13
7L
14
8H
15
8L
16
5.1.2.1.1 Single-Ended Measurements — Overview
Related Topics:
‡Single-Ended Measurements — Overview (p. 65)
‡Single-Ended Measurements — Details (p. 307)
A single-ended measurement measures the difference in voltage between the
terminal configured for single-ended input and the reference ground. The
measurement sequence is illustrated in figure Simplified Voltage Measurement
Sequence (p. 306). While differential measurements are usually preferred, a singleended measurement is often adequate in applications wherein some types of noise
are not a problem and care is taken to avoid problems caused by ground currents.
Examples of applications wherein a single-ended measurement may be preferred
include:
x
x
x
Not enough differential terminals available. Differential measurements use
twice as many H/L] terminals as do single-ended measurements.
Rapid sampling is required. Single-ended measurement time is about half
that of differential measurement time.
Sensor is not designed for differential measurements. Many Campbell
Scientific sensors are not designed for differential measurement, but the draw
backs of a single-ended measurement are usually mitigated by large
programmed excitation and/or sensor output voltages.
65
Section 5. System Overview
However, be aware that because a single-ended measurement is referenced to
CR1000 ground, any difference in ground potential between the sensor and the
CR1000 will result in error, as emphasized in the following examples:
x
x
If the measuring junction of a thermocouple used to measure soil temperature
is not insulated, and the potential of earth ground is greater at the sensor than
at the point where the CR1000 is grounded, a measurement error will result.
For example, if the difference in grounds is 1 mV, with a copper-constantan
thermocouple, the error will be approximately 25 °C.
If signal conditioning circuitry, such as might be found in a gas analyzer, and
the CR1000 use a common power supply, differences in current drain and
lead resistance often result in different ground potentials at the two
instruments despite the use of a common ground. A differential measurement
should be made on the analog output from the external signal conditioner to
avoid error.
5.1.2.1.2 Differential Measurements — Overview
Related Topics:
‡Differential Measurements — Overview (p. 66)
‡Differential Measurements — Details (p. 308)
Summary Use a differential configuration when making voltage measurements,
unless constrained to do otherwise.
A differential measurement measures the difference in voltage between two input
terminals. Its sequence is illustrated in the figure Simplified Differential-Voltage
Measurement Sequence (p. 66), and is characterized by multiple automatic
measurements, the results of which are averaged automatically before the final
value is reported. For example, the sequence on a differential measurement using
the VoltDiff() instruction involves two measurements — first with the high input
referenced to the low, then with the inputs reversed. Reversing the inputs before
the second measurement cancels noise common to both leads as well as small
errors caused by junctions of different metals that are throughout the measurement
electronics.
Figure 20. Simplified Differential-Voltage Measurement Sequence
5.1.2.2 Current Measurements — Overview
Related Topics:
‡Current Measurements — Overview (p. 66)
‡Current Measurements — Details (p. 337)
66
Section 5. System Overview
A measurement of current is accomplished through the use of external resistors to
convert current to voltage, then measure the voltage as explained in the section
Differential Measurements — Overview (p. 66). The voltage is measured with the
CR1000 voltage measurement circuitry.
5.1.2.3 Resistance Measurements — Overview
Related Topics:
‡5HVLVWDQFH0HDVXUHPHQWV— Specifications
‡Resistance Measurements — Overview (p. 67)
‡Resistance Measurements — Details (p. 337)
‡Resistance Measurements — Instructions (p. 551)
Many analog sensors use a variable-resistive device as the fundamental sensing
element. These elements are placed in a wheatstone bridge or related circuit. The
CR1000 can measure most bridge circuit configurations. A bridge measurement
is a special case voltage measurement. Examples include:
x
x
Strain gage: resistance in a pressure-transducer strain gage correlates to a
water pressure.
Position potentiometer: a change in resistance in a wind-vane potentiometer
correlates to a change in wind direction.
5.1.2.3.1 Voltage Excitation
Bridge resistance is determined by measuring the difference between a known
voltage applied to the excitation (input) arm of a resistor bridge and the voltage
measured on the output arm. The CR1000 supplies a precise-voltage excitation
via Vx terminals . Return voltage is measured on H/L] terminals configured for
single-ended or differential input. Examples of bridge-sensor wiring using
voltage excitation are illustrated in figures Half-Bridge Wiring — Wind Vane
Potentiometer (p. 67) and Full-Bridge Wiring — Pressure Transducer (p. 68).
Figure 21. Half-Bridge Wiring Example — Wind Vane Potentiometer
67
Section 5. System Overview
Figure 22. Full-Bridge Wiring Example — Pressure Transducer
5.1.2.4 Strain Measurements — Overview
Related Topics:
‡Strain Measurements — Overview (p. 68)
‡Strain Measurements — Details (p. 342)
‡FieldCalStrain() Examples (p. 223)
Strain gage measurements are usually associated with structural-stress analysis.
When making strain measurements, please first consult with a Campbell Scientific
application engineer.
5.1.3
Pulse Measurements — Overview
Related Topics
‡3XOVH0HDVXUHPHQWV— Specifications
‡Pulse Measurements — Overview (p. 68)
‡Pulse Measurements — Details (p. 349)
‡Pulse Measurements — Instructions (p. 553)
The output signal generated by a pulse sensor is a series of voltage waves. The
sensor couples its output signal to the measured phenomenon by modulating wave
frequency. The CR1000 detects the state transition as each wave varies between
voltage extremes (high-to-low or low-to-high). Measurements are processed and
presented as counts, frequency, or timing data.
P terminals are configurable for pulse input to measure counts or frequency from
the following signal types:
x
x
x
High-frequency 5 Vdc square-wave
Switch closure
Low-level ac
C terminals configurable for input for the following:
x
x
68
State
Edge counting
Section 5. System Overview
x
Edge timing
o
Resolution — 540 ns
Note A period-averaging sensor has a frequency output, but it is connected to a
SE terminal configured for period-average input and measured with the
PeriodAverage() instruction (see section Period Averaging — Overview (p. 70) ).
5.1.3.1 Pulses Measured
Pulse outputs vary. These variations are illustrated in the figure Pulse-Sensor
Output-Signal Types (p. 69).
Figure 23. Pulse-Sensor Output-Signal Types
5.1.3.2 Pulse-Input Channels
Table Pulse-Input Channels and Measurements (p. 69) lists devices, channels and
options for measuring pulse signals.
Table 3. Pulse-Input Terminals and Measurements
Pulse-Input
Terminal
P Terminal
Input Type
x
Low-level ac
x
High-frequency
x
Switch-closure
x
C Terminal
Low-level ac
with LLAC4 (p.
646) module
x
High-frequency
x
Switch-closure
Data Option
x
Counts
x
Frequency
x
Run average
of frequency
x
Counts
x
Frequency
x
Running
average of
frequency
x
Interval
x
Period
x
State
CRBasic
Instruction
PulseCount()
PulseCount()
TimerIO()
69
Section 5. System Overview
5.1.3.3 Pulse Sensor Wiring
Read More See the section Pulse Measurement Tips (p. 356)
An example of a pulse sensor connection is illustrated in figure Pulse-Input
Wiring Example — Anemometer Switch (p. 70). Pulse sensors have two active
wires, one of which is ground. Connect the ground wire to a
(signal ground)
terminal. Connect the other wire to a P terminal. Sometimes the sensor will
require power from the CR1000, so there may be two power wires — one of
which will be power ground. Connect power ground to a G terminal. Do not
confuse the pulse wire with the positive-power wire, or damage to the sensor or
CR1000 may result. Some switch-closure sensors may require a pull-up resistor.
Figure 24. Pulse-Input Wiring Example — Anemometer
5.1.4
Period Averaging — Overview
Related Topics:
‡3HULRG$YHUDJLQJ— Specifications
‡Period Averaging — Overview (p. 70)
‡Period Averaging — Details (p. 360)
The CR1000 can measure the period of an analog signal.
Numbered SE terminals are configurable for period average:
x
x
x
Voltage gain: 1, 10, 33, 100
Maximum frequency: 200 kHz
Resolution: 136 ns
Note Both pulse-count and period-average measurements are used to measure
frequency output sensors. Yet pulse-count and period-average measurement
methods are different. Pulse-count measurements use dedicated hardware — pulse
count accumulators, which are always monitoring the input signal, even when the
CR1000 is between program scans. In contrast, period-average measurement
instructions only monitor the input signal during a program scan. Consequently,
pulse-count scans can usually be much less frequent than period-average scans.
Pulse counters may be more susceptible to low-frequency noise because they are
70
Section 5. System Overview
always "listening", whereas period averaging may filter the noise by reason of
being "asleep" most of the time. Pulse-count measurements are not appropriate for
sensors that are powered off between scans, whereas period-average
measurements work well since they can be placed in the scan to execute only
when the sensor is powered and transmitting the signal.
Period-average measurements use a high-frequency digital clock to measure time
differences between signal transitions, whereas pulse-count measurements simply
accumulate the number of counts. As a result, period-average measurements offer
much better frequency resolution per measurement interval, as compared to pulsecount measurements. The frequency resolution of pulse-count measurements can
be improved by extending the measurement interval by increasing the scan
interval and by averaging. For information on frequency resolution, see
Frequency Resolution (p. 353).
5.1.5
Vibrating-Wire Measurements — Overview
Related Topics:
‡9LEUDWLQJ-Wire Measurements — Specifications
‡Vibrating-Wire Measurements — Overview (p. 71)
‡Vibrating-Wire Measurements — Details (p. 361)
Vibrating-wire sensors impart long term stability to many environmental and
industrial measurement applications. The CR1000 is equipped to measure these
sensors either directly or through interface modules.
A thermistor included in most sensors can be measured to compensate for
temperature errors.
Measuring the resonant frequency by means of period averaging is the classic
technique, but Campbell Scientific has developed static and dynamic spectralanalysis techniques (VSPECTTM (p. 532)) that produce superior noise rejection,
higher resolution, diagnostic data, and, in the case of dynamic VSPECT,
measurements up to 333.3 Hz. Dynamic measurements require addition of an
interface module.
SE terminals are configurable for time-domain vibrating-wire measurement,
which is a technique now superseded in most applications by VSPECT (p. 532)
vibrating-wire analysis. See appendix Vibrating-Wire Input Modules List (p. 647)
for more information
5.1.6
Reading Smart Sensors — Overview
Related Topics:
‡Reading Smart Sensors — Overview (p. 71)
‡Reading Smart Sensors — Details (p. 362)
A smart sensor is equipped with independent measurement circuitry that makes
the basic measurement and sends measurement and measurement related data to
the CR1000. Smart sensors vary widely in output modes. Many have multiple
output options. Output options supported by the CR1000 include SDI-12 (p. 267),
RS-232 (p. 245), Modbus (p. 411), and DNP3 (p. 408).
The following smart sensor types can be measured on the indicated terminals:
71
Section 5. System Overview
x
x
x
x
x
SDI-12 devices: C
Synchronous Devices for Measurement (SDM): C
Smart sensors: C terminals, RS-232 port, and CS I/O port with the
appropriate interface.
Modbus or DNP3 network: RS-232 port and CS I/O port with the appropriate
interface
Other serial I/O devices: C terminals, RS-232 port, and CS I/O port with the
appropriate interface
5.1.6.1 SDI-12 Sensor Support — Overview
Related Topics:
‡SDI-12 Sensor Support — Overview (p. 72)
‡SDI-12 Sensor Support — Details (p. 363)
‡Serial I/O: SDI-12 Sensor Support — Programming Resource (p. 267)
‡SDI-12 Sensor Support — Instructions (p. 555)
SDI-12 is a smart-sensor protocol that uses one SDI-12 port and is powered by 12
Vdc. It is fully supported by the CR1000 datalogger. Refer to the chart CR1000
Terminal Definitions (p. 76), which indicates C terminals that can be configured for
SDI-12 input. For more information about SDI-12 support, see section Serial I/O:
SDI-12 Sensor Support — Details (p. 267).
5.1.6.2 RS-232 — Overview
The CR1000 has 6 ports available for RS-232 input as shown in figure Terminals
Configurable for RS-232 Input (p. 73).
Note With the correct adapter, the CS I/O port can often be used as an RS-232
I/O port.
As indicated in figure Use of RS-232 and Digital I/O when Reading RS-232
Devices (p. 73), RS-232 sensors can often be connected to C terminal pairs
configured for serial I/O, to the RS-232 port, or to the CS I/O port with the proper
adapter. Ports can be set up for baud rate, parity, stop-bit, and so forth as
described in CRBasic Editor Help.
72
Section 5. System Overview
Figure 25. Terminals Configurable for RS-232 Input
Figure 26. Use of RS-232 and Digital I/O when Reading RS-232 Devices
5.1.7
Field Calibration — Overview
Related Topics:
‡Field Calibration — Overview (p. 73)
‡Field Calibration — Details (p. 210)
Calibration increases accuracy of a measurement device by adjusting its output, or
the measurement of its output, to match independently verified quantities.
Adjusting sensor output directly is preferred, but not always possible or practical.
By adding FieldCal() or FieldCalStrain() instructions to the CR1000 CRBasic
program, measurements of a linear sensor can be adjusted by modifying the
programmed multiplier and offset applied to the measurement.
73
Section 5. System Overview
5.1.8
Cabling Effects — Overview
Related Topics:
‡Cabling Effects — Overview (p. 74)
‡Cabling Effects — Details (p. 364)
Sensor cabling can have significant effects on sensor response and accuracy. This
is usually only a concern with sensors acquired from manufacturers other than
Campbell Scientific. Campbell Scientific sensors are engineered for optimal
performance with factory-installed cables.
5.1.9
Synchronizing Measurements — Overview
Related Topics:
‡Synchronizing Measurements — Overview (p. 74)
‡Synchronizing Measurements — Details (p. 365)
Timing of a measurement is usually controlled relative to the CR1000 clock.
When sensors in a sensor network are measured by a single CR1000,
measurement times are synchronized, often within a few milliseconds, depending
on sensor number and measurement type. Large numbers of sensors, cable length
restrictions, or long distances between measurement sites may require use of
multiple CR1000s.
5.2
PLC Control — Overview
Related Topics:
‡PLC Control — Overview (p. 74)
‡PLC Control — Details (p. 244)
‡PLC Control Modules — Overview (p. 368)
‡PLC Control Modules — Lists (p. 648)
‡PLC Control — Instructions (p. 562)
‡6ZLWFKHG9ROWDJH2XWSXW— Specifications
‡Switched Voltage Output — Overview (p. 78)
‡Switched Voltage Output — Details (p. 103)
This section is slated for expansion. Below are a few tips.
x
x
x
x
74
Short Cut programming wizard has provisions for simple on/off control.
PID control can be done with the CR1000. Ask a Campbell Scientific
application engineer for more information.
When controlling a PID algorithm, a delay between processing (algorithm
input) and the control (algorithm output) is not usually desirable. A delay
will not occur in either sequential mode (p. 527) or pipeline mode (p. 523),
assuming an appropriately fast scan interval is programmed, and the program
is not skipping scans. In sequential mode, if some task occurs that pushes
processing time outside the scan interval, skipped scans will occur and the
PID control may fail. In pipeline mode, with an appropriately sized scan
buffer, no skipped scans will occur. However, the PID control may fail as the
processing instructions work through the scan buffer.
To avoid these potential problems, bracket the processing instructions in the
CRBasic program with ProcHiPri and EndProcHiPri. Processing
Section 5. System Overview
instructions between these instructions are given the same high priority as
measurement instructions and do not slip into the scan buffer if processing
time is increased. ProcHiPri and EndProcHiPri may not be selectable in
CRBasic Editor. You can type them in anyway, and the compiler will
recognize them.
5.3
Datalogger — Overview
Related Topics:
‡Datalogger — Quickstart (p. 43)
‡Datalogger — Overview (p. 75)
‡Dataloggers — List (p. 645)
The CR1000 datalogger is the principal component of a data-acquisition system.
It is a precision instrument designed for demanding environments and low-power
applications. CPU, analog and digital measurements, analog and digital outputs,
and memory usage are controlled by the operating system, the on-board clock, and
the CRBasic application program you write.
The application program is written in CRBasic, a programming language that
includes measurement, data processing, and analysis routines and a standard
BASIC instruction set. Short Cut (p. 528), a very user-friendly program generator
software application, can be used to write programs for many basic measurement
and control applications. CRBasic Editor, a software application available in
some datalogger support software (p. 512) packages, is used to write more complex
programs.
Measurement data are stored in non-volatile memory. Most applications do not
require that every measurement be recorded. Rather, measurements are usually
combined in statistical or computational summaries. The CR1000 has the option
of evaluating programmed instructions sequentially (sequential mode), or in the
more efficient pipeline mode. In pipeline mode, the CR1000 determines the order
of instruction execution.
5.3.1
Time Keeping — Overview
Related Topics:
‡Time Keeping — Overview (p. 75)
‡Time Keeping — Instructions (p. 578)
Nearly all CR1000 functions depend on the internal clock. The operating system
and the CRBasic user program use the clock for scheduling operations. The
CRBasic program times functions through various instructions, but the method of
timing is nearly always in the form of "time into an interval." For example, 6:00
AM is represented in CRBasic as "360 minutes into a 1440 minute interval", 1440
minutes being the length of a day and 360 minutes into that day corresponding to
6:00 AM.
Zero minutes into an interval puts it at the "top" of that interval, that is at the
beginning of the second, minute, hours, or day. For example, 0 minutes into a
1440 minute interval corresponds to Midnight. When an interval of a week is
programmed, the week begins at Midnight on Monday morning.
75
Section 5. System Overview
5.3.2
Wiring Panel — Overview
Related Topics
‡Wiring Panel — Quickstart (p. 43)
‡Wiring Panel — Overview (p. 76)
‡Measurement and Control Peripherals (p. 366)
The wiring panel of the CR1000 is the interface to most functions. These
functions are introduced in the following sections while reviewing wiring-panel
features illustrated in the figure Wiring Panel (p. 44). The table CR1000 Terminal
Definitions (p. 76) details the functions of the various terminals on the wiring panel.
Measurement and control peripherals expand the input and output capabilities of
the wiring panel.
Figure 27. Wiring Panel
76
Section 5. System Overview
Table 4. CR1000 Wiring Panel Terminal Definitions
H
L
H
L
H
L
H
L
H
L
H
L
H
L
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
COM4
T
x
T
x
T
x
T
x
R
x
R
x
R
x
R
x
Max
L
COM3
CS I/O
H
COM2
RS-
ňʼn
COM1
SW-12
16
12V
ňʼn
15
12V
14
5V
ňʼn
13
C8
12
C7
ňʼn
11
C6
10
C5
ňʼn
9
C4
8
C3
ňʼn
7
C2
6
C1
ňʼn
5
P2
4
P1
ňʼn
3
VX3
2
VX2
DIFF
1
VX1
Labels
SE
Analog Input
Single-ended
Differential (high/low)
9
Analog period average
2
Vibrating wire
9
9
9
9
9
9
1
6
8
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
1
6
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
1
6
Analog Output
Switched Precision Voltage
9
9
3
9
Pulse Counting
Switch closure
9
9
9
9
9
9
9
9
9
9
1
0
High frequency
9
9
9
9
9
9
9
9
9
9
1
0
Low-level Vac
9
9
2
Function
Digital I/O
Control
9
Status
9
General I/O (TX,RX)
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
8
9
8
4
9
Pulse-width modulation
9
9
9
9
9
9
9
9
8
Timer I/O
9
9
9
9
9
9
9
9
8
9
9
9
9
9
9
9
9
8
Interrupt
Continuous Regulated
3
5 Vdc
Continuous Unregulated
3
12 Vdc
Switched Regulated
1
9
9
2
9
3
5 Vdc
Switched Unregulated
9
9
9
9
9
9
9
8
9
3
12 Vdc
1
9
UART
True RS-232 (TX/RX)
9
9
TTL RS-232 (TX/RX)
SDI-12
SDM (Data/Clock/Enable)
9
9
9
9
9
9
4
2
4
9
4
9
1
9
77
Section 5. System Overview
1
2
3
4
Terminal expansion modules are available.
Static, frequency-domain measurement
Check the table Current Source and Sink Limits (p. 103)
Requires an interfacing device for sensor input. See the table CS I/O to RS-232 Interfaces (p. 651).
5.3.2.1 Switched Voltage Output — Overview
Related Topics:
‡6ZLWFKHG9ROWDJH2XWSXW— Specifications
‡Switched Voltage Output — Overview (p. 78)
‡Switched Voltage Output — Details (p. 103)
‡PLC Control — Overview (p. 74)
‡PLC Control — Details (p. 244)
‡PLC Control Modules — Overview (p. 368)
‡PLC Control Modules — Lists (p. 648)
‡PLC Control — Instructions (p. 562)
C terminals are selectable as binary inputs, control outputs, or communication
ports. See the section Measurement — Overview (p. 62) for a summary of
measurement functions. Other functions include device-driven interrupts,
asynchronous communications and SDI-12 communications. Table CR1000
Terminal Definitions (p. 76) summarizes available options.
Figure Control and Monitoring with C Terminals (p. 79) illustrates a simple
application wherein a C terminal configured for digital input and another
configured for control output are used to control a device (turn it on or off) and
monitor the state of the device (whether the device is on or off).
78
Section 5. System Overview
Figure 28. Control and Monitoring with C Terminals
5.3.2.2 Voltage Excitation — Overview
Related Topics:
‡9ROWDJHDQG&XUUHQW([FLWDWLRQ— Specifications
‡Voltage Excitation — Overview (p. 79)
The CR1000 has several terminals designed to supply switched voltage to
peripherals, sensors, or control devices:
x
x
x
x
x
Voltage Excitation (switched-analog output) — Vx terminals supply precise
voltage in the range of ±2500 mV. These terminals are regularly used with
resistive-bridge measurements. Each terminal will source up to r25 mA.
Digital I/O — C terminals configured for on / off and PWM (pulse width
modulation) or PDM (pulse duration modulation) on C4, C5 and C7.
Switched 12 Vdc — SW12 terminals. Primary battery voltage under
program control to switch external devices (such as humidity sensors)
requiring nominal 12 Vdc. SW12 terminals can source up to 900 mA. See
the table Current Source and Sink Limits (p. 103).
Continuous Analog Output — available by adding a peripheral analog output
device available from Campbell Scientific. Refer to section Analog-Output
Modules (p. 367) for information on available expansion modules.
79
Section 5. System Overview
5.3.2.3 Grounding Terminals
Read More See Grounding (p. 105).
Proper grounding lends stability and protection to a data acquisition system. It is
the easiest and least expensive insurance against data loss — and often the most
neglected. The following terminals are provided for connection of sensor and
CR1000 datalogger grounds:
x
x
x
x
Signal Ground ( ) — reference for single-ended analog inputs, pulse inputs,
excitation returns, and as a ground for sensor shield wires. Signal returns for
pulse inputs should use
terminals located next to the pulse input terminal.
Current loop sensors, however, should be grounded to power ground.
Power Ground (G) — return for 5V, SW12, 12V, current loop sensors, and C
configured for control. Use of G grounds for these outputs minimizes
potentially large current flow through the analog-voltage-measurement
section of the wiring panel, which can cause single-ended voltage
measurement errors.
Earth Ground Lug ( ) — connection point for a heavy-gage earth-ground
wire. A good earth connection is necessary to secure the ground potential of
the CR1000 and shunt transients away from electronics. Minimum 14 AWG
wire is recommended.
5.3.2.4 Power Terminals
Related Topics:
‡3RZHU6XSSOLHV— Specifications
‡Power Supplies — Quickstart (p. 44)
‡Power Supplies — Overview (p. 85)
‡Power Supplies — Details (p. 100)
‡Power Supplies — Products (p. 657)
‡Power Sources (p. 101)
‡Troubleshooting — Power Supplies (p. 494)
5.3.2.4.1 Power In
The POWER IN connector is the connection point for external power supply
components.
5.3.2.4.2 Power Out Terminals
Note Refer to the section Switched Voltage Output — Details (p. 103) for more
information on using the CR1000 as a power supply for sensors and peripheral
devices.
The CR1000 can be used as a power source for sensors and peripherals. The
following voltages are available:
x
80
12V terminals: unregulated nominal 12 Vdc. This supply closely tracks the
primary CR1000 supply voltage, so it may rise above or drop below the
power requirement of the sensor or peripheral. Precautions should be taken
to prevent damage to sensors or peripherals from over- or under-voltage
Section 5. System Overview
x
conditions, and to minimize the error associated with the measurement of
underpowered sensors. See section Power Supplies — Overview (p. 85).
5V terminals: regulated 5 Vdc at 300 mA. The 5 Vdc supply is regulated to
within a few millivolts of 5 Vdc so long as the main power supply for the
CR1000 does not drop below <MinPwrSupplyVolts>.
5.3.2.5 Communication Ports
Read More See sections RS-232 and TTL (p. 362), Data Retrieval and
Telecommunications — Details (p. 391), and PakBus — Overview (p. 88).
The CR1000 is equipped with hardware ports that allow communication with
other devices and networks, such as:
x
x
x
x
x
x
x
x
PC
Smart sensors
Modbus and DNP3 networks
Ethernet
Modems
Campbell Scientific PakBus networks
Other Campbell Scientific dataloggers
Campbell Scientific datalogger peripherals
Communication ports include:
x
x
x
x
x
x
x
x
CS I/O
RS-232
SDI-12
SDM
CPI (requires a peripheral device)
Ethernet (requires a peripheral device)
Peripheral Port — supports Ethernet and CompactFlash memory card
modules
5.3.2.5.1 CS I/O Port
Read More See the appendix Serial Port Pinouts (p. 633).
x
One nine-pin port, labeled CS I/O, for communicating with a PC or modem
through Campbell Scientific communication interfaces, modems, or
peripherals. CS I/O telecommunication interfaces are listed in the appendix
Serial I/O Modules List (p. 646).
Note CS I/O communications normally operate well over only a few feet of serial
cable.
81
Section 5. System Overview
5.3.2.5.2 RS-232 Ports
Note RS-232 communications normally operate well up to a transmission cable
capacitance of 2500 picofarads, or approximately 50 feet of commonly available
serial cable.
x
One nine-pin DCE port, labeled RS-232, normally used to communicate with
a PC running datalogger support software (p. 654), or to connect a third-party
modem. With a null-modem adapter attached, it serves as a DTE device.
Read More See the appendix Serial Port Pinouts (p. 633).
x
Two-terminal (TX and RX) RS-232 ports can be configured:
o
Up to Four TTL ports, configured from C terminals.
Note RS-232 ports are not isolated (p. 518).
5.3.2.5.3 Peripheral Port
Provided for connection of some Campbell Scientific CF memory card modules
and IP network link hardware. See the appendices Network Links List (p. 652) and
Data Storage Devices — List (p. 653). See the section Memory Card (CRD: Drive)
— Overview (p. 89) for precautions when using memory cards.
Read More See the section TCP/IP (p. 289).
x
One multi-pin port, labeled Peripheral Port.
5.3.2.5.4 SDI-12 Ports
Read More See the section Serial I/O: SDI-12 Sensor Support — Details (p. 267).
SDI-12 is a 1200 baud protocol that supports many smart sensors. Each port
requires one terminal and supports up to 16 individually addressed sensors.
x
Up to four ports configured from C terminals.
5.3.2.5.5 SDM Port
SDM is a protocol proprietary to Campbell Scientific that supports several
Campbell Scientific digital sensor and telecommunication input and output
expansion peripherals and select smart sensors.
x
One SDM port configured from C1, C2, and C3 terminals.
5.3.2.5.6 CPI Port
CPI is a new proprietary protocol that supports an expanding line of Campbell
Scientific CDM modules. CDM modules are higher-speed input- and outputexpansion peripherals. CPI ports also enable networking between compatible
Campbell Scientific dataloggers.
x
82
Connection to CDM devices requires a peripheral CPI interface as listed in
the appendix CDM/CPI Interfaces (p. 647).
Section 5. System Overview
5.3.2.5.7 Ethernet Port
Read More See the section TCP/IP (p. 289).
x
5.3.3
Ethernet capability requires a peripheral Ethernet interface device, as listed
in the appendix Network Links List (p. 652).
Keyboard Display — Overview
Related Topics:
‡Keyboard Display — Overview (p. 83)
‡Keyboard Display — Details (p. 451)
‡Keyboard Display — List (p. 651)
‡Custom Menus — Overview (p. 84, p. 581)
The CR1000KD Keyboard Display is a powerful tool for field use. The
CR1000KD, illustrated in figure CR1000KD Keyboard Display (p. 83), is a
peripheral optional to the CR1000.
The keyboard display is an essential installation, maintenance, and
troubleshooting tool for many applications. It allows interrogation and
programming of the CR1000 datalogger independent of other telecommunication
links. More information on the use of the keyboard display is available in the
section Custom Menus — Overview (p. 84, p. 581). See the appendix Keyboard
Displays List (p. 651) for more information on available products.
Figure 29. CR1000KD Keyboard Display
5.3.3.1 Character Set
The keyboard display character set is accessed using one of the following three
procedures:
x
Most keys have a characters shown in blue printed above the key. To enter a
character, press Shift one to three times to select the position of the character
shown above the key, then press the key. For example, to enter Y, press Shift
three times, then press the PgDn.
83
Section 5. System Overview
x
x
To insert a space (Spc) or change case (Cap), press Shift one to two times for
the position, then press BkSpc.
To insert a character not printed on the keyboard, enter Ins , scroll down to
Character, press Enter, then scroll up, down, left, or right to the desired
character in the list, then press Enter.
5.3.3.2 Custom Menus — Overview
Related Topics:
‡Custom Menus — Overview (p. 84, p. 581)
‡Data Displays: Custom Menus — Details (p. 182)
‡Custom Menus — Instruction Set (p. 581)
‡Keyboard Display — Overview (p. 83)
‡CRBasic Editor Help for DisplayMenu()
CRBasic programming in the CR1000 facilitates creation of custom menus for the
CR1000KD Keyboard Display.
Figure Custom Menu Example (p. 84) shows windows from a simple custom menu
named DataView. DataView appears as the main menu on the keyboard display.
DataView has menu item Counter, and submenus PanelTemps, TCTemps and
System Menu. Counter allows selection of one of four values. Each submenu
displays two values from CR1000 memory. PanelTemps shows the CR1000
wiring-panel temperature at each scan, and the one-minute sample of panel
temperature. TCTemps displays two thermocouple temperatures. For more
information on creating custom menus, see section Data Displays: Custom Menus
— Details (p. 182).
Figure 30. Custom Menu Example
84
Section 5. System Overview
5.3.4
Measurement and Control Peripherals — Overview
Related Topics:
‡Measurement and Control Peripherals — Overview (p. 85)
‡Measurement and Control Peripherals — Details (p. 366)
‡Measurement and Control Peripherals — Lists (p. 645)
Modules are available from Campbell Scientific to expand the number of
terminals on the CR1000. These include:
Multiplexers
Multiplexers increase the input capacity of terminals configured for analog-input,
and the output capacity of Vx excitation terminals.
SDM Devices
Serial Device for Measurement expand the input and output capacity of the
CR1000. These devices connect to the CR1000 through terminals C1, C2, and
C3.
CDM Devices
Campbell Distributed Modules are a growing line of measurement and control
modules that use the higher speed CAN Peripheral Interface (CPI) bus
technology. These connect through the SC-CPI interface.
5.3.5
Power Supplies — Overview
Related Topics:
‡3RZHU6XSSOLHV— Specifications
‡Power Supplies — Quickstart (p. 44)
‡Power Supplies — Overview (p. 85)
‡Power Supplies — Details (p. 100)
‡Power Supplies — Products (p. 657)
‡Power Sources (p. 101)
‡Troubleshooting — Power Supplies (p. 494)
The CR1000 is powered by a nominal 12 Vdc source. Acceptable power range is
9.6 to 16 Vdc.
External power connects through the green POWER IN connector on the face of
the CR1000. The positive power lead connects to 12V. The negative lead
connects to G. The connection is internally reverse-polarity protected.
The CR1000 is internally protected against accidental polarity reversal on the
power inputs.
The CR1000 has a modest-input power requirement. For example, in low-power
applications, it can operate for several months on non-rechargeable batteries.
Power systems for longer-term remote applications typically consist of a charging
source, a charge controller, and a rechargeable battery. When ac line power is
available, a Vac-to-Vac or Vac-to-Vdc wall adapter, a peripheral charging
85
Section 5. System Overview
regulator, and a rechargeable battery can be used to construct a UPS (uninterruptible power supply).
5.3.6
CR1000 Configuration — Overview
Related Topics:
‡CR1000 Configuration — Overview (p. 86)
‡CR1000 Configuration — Details (p. 111)
‡Status, Settings, and Data Table Information (Status/Settings/DTI) (p. 603)
The CR1000 is shipped factory-ready with an operating system (OS) installed.
Settings default to those necessary to communicate with a PC via RS-232 and to
accept and execute user-application programs. For more complex applications,
some settings may need adjustment. Settings can be changed with the following:
x
x
x
DevConfig (Device Configuration Utility). See section Device Configuration
Utility (p. 111) )
CR1000KD Keyboard Display. See section Keyboard Display — Details (p.
451) and the appendix Keyboard Display — List (p. 651)
Datalogger support software. See section Datalogger Support Software —
Overview (p. 95).
OS files are sent to the CR1000 with DevConfig or through the program Send
button in datalogger support software. When the OS is sent with DevConfig, most
settings are cleared, whereas, when sent with datalogger support software, most
settings are retained. Operating systems can also be transferred to the CR1000
with a Campbell Scientific mass storage device or memory card.
OS updates are occasionally made available at www.campbellsci.com. OS and
settings remain intact when power is cycled.
5.3.7
CRBasic Programming — Overview
Related Topics:
‡CRBasic Programming — Overview (p. 86)
‡CRBasic Programming — Details (p. 122)
‡CRBasic Programming — Instructions (p. 537)
‡Programming Resource Library (p. 169)
‡CRBasic Editor Help
A CRBasic program directs the CR1000 how and when sensors are to be
measured, calculations made, and data stored. A program is created on a PC and
sent to the CR1000. The CR1000 can store a number of programs in memory, but
only one program is active at a given time. Two Campbell Scientific software
applications, Short Cut and CRBasic Editor, are used to create CR1000 programs.
x
x
86
Short Cut creates a datalogger program and wiring diagram in four easy steps.
It supports most sensors sold by Campbell Scientific and is recommended for
creating simple programs to measure sensors and store data.
Programs generated by Short Cut are easily imported into CRBasic Editor for
additional editing. For complex applications, experienced programmers often
create essential measurement and data storage code with Short Cut, then add
more complex code with CRBasic Editor.
Section 5. System Overview
Note Once a Short Cut generated program has been edited with CRBasic Editor
it can no longer be modified with Short Cut.
(p. 125),
5.3.8
Memory — Overview
Related Topics:
‡Memory — Overview (p. 87)
‡Memory — Details (p. 370)
‡Data Storage Devices — List (p. 653)
Data concerning CR1000 memory are posted in the Status (p. 603) table. Memory
is organized as follows:
x
OS Flash
o
o
o
o
o
x
2 MB
Operating system (OS)
Serial number and board rev
Boot code
Erased when loading new OS (boot code only erased if changed)
Serial Flash
o
o
o
o
o
512 KB
Device settings
Write protected
Non-volatile
CPU: drive residence
Automatically allocated
FAT file system
Limited write cycles (100,000)
Slow (serial accesses)
x
Main Memory
o
o
o
o
o
o
o
o
4 MB SRAM
Battery backed
OS variables
CRBasic compiled program binary structure (490 KB maximum)
CRBasic variables
Data memory
Communication memory
USR: drive
User allocated
FAT32 RAM drive
Photographic images (See the appendix Cameras )
Data files from TableFile() instruction (TOA5, TOB1, CSIXML
and CSIJSON)
o
o
Keep (p. 519) memory (OS variables not initialized)
Dynamic runtime memory allocation
Note CR1000s with serial numbers smaller than 11832 were usually supplied
with only 2 MB of SRAM.
87
Section 5. System Overview
Memory for data can be increased with the addition of a CF (p. 510) card and CF
storage module (connects to the Peripheral port) or a mass storage device (thumb
drive) that connects to CS I/O or both. See the appendix Data-Storage Devices
— List (p. 653) for information on available memory expansion products.
By default, final-data memory (memory for stored data) is organized as ring
memory. When the ring is full, oldest data are overwritten by newest data. The
DataTable() instruction, however, has an option to set a data table to Fill and
Stop.
5.3.9
Data Retrieval and Telecommunications — Overview
Related Topics:
‡Data Retrieval and Telecommunications — Quickstart (p. 45)
‡Data Retrieval and Telecommunications — Overview (p. 88)
‡Data Retrieval and Telecommunications — Details (p. 391)
‡Data Retrieval and Telecommunication Peripherals — Lists (p. 651)
Final data are written to tables in final-data memory. When retreived, data are
copied to PC files via a telecommunication link (Data Retrieval and
Telecommunications — Details (p. 391) ) or by transporting a CompactFlash® (CF)
card (CRD: drive) or a Campbell Scientific mass storage media (USB: drive) to
the PC.
5.3.9.1 PakBus® Communications — Overview
Related Topics:
‡PakBus® Communications — Overview (p. 88)
‡PakBus® Communications — Details (p. 393)
‡PakBus® Communications — Instructions (p. 584)
‡ PakBus Networking Guide (available at www.campbellsci.com/manuals
(http://www.campbellsci.com/manuals))
The CR1000 communicates with datalogger support software (p. 654),
telecommunication peripherals (p. 651), and other dataloggers (p. 645) with PakBus, a
proprietary network communication protocol. PakBus is a protocol similar in
concept to IP (Internet Protocol). By using signatured data packets, PakBus
increases the number of communication and networking options available to the
CR1000. Communication can occur via TCP/IP, on the RS-232 port, CS I/O
port, and C terminals.
Advantages of PakBus are as follows:
x
x
x
x
88
Simultaneous communication between the CR1000 and other devices.
Peer-to-peer communication — no PC required. Special CRBasic
instructions simplify transferring data between dataloggers for distributed
decision making or control.
Data consolidation — other PakBus dataloggers can be used as "sensors" to
consolidate all data into one CR1000.
Routing — the CR1000 can act as a router, passing on messages intended for
another Campbell Scientific datalogger. PakBus supports automatic route
detection and selection.
Section 5. System Overview
x
Short distance networks — with no extra hardware, a CR1000 can talk to
another CR1000 over distances up to 30 feet by connecting transmit, receive
and ground wires between the dataloggers.
In a PakBus network, each datalogger is set to a unique address. The default
PakBus address in most devices is 1. To communicate with the CR1000, the
datalogger support software must know the CR1000 PakBus address. The PakBus
address is changed using the CR1000KD Keyboard Display (p. 451), DevConfig
utility (p. 111), CR1000 Status table (p. 603), or PakBus Graph (p. 522) software.
5.3.9.2 Telecommunications
Data are usually copied through a telecommunication link to a file on the
supporting PC using Campbell Scientific datalogger support software (p. 654). See
also the manual and Help for the software being used.
5.3.9.3 Mass-Storage Device
Caution When removing a Campbell Scientific mass storage device (thumb
drive) from the CR1000, do so only when the LED is not lit or flashing.
Removing the device while it is active can cause data corruption.
Data stored on a Campbell Scientific mass storage device are retrieved via a
telecommunication link to the CR1000, if the device remains on the CS I/O port,
or by removing the device, connecting it to a PC, and copying files using
Windows File Explorer.
5.3.9.4 Memory Card (CRD: Drive) — Overview
Related Topics:
‡Memory Card (CRD: Drive) — Overview (p. 89)
‡Memory Card (CRD: Drive) — Details (p. 376)
‡Memory Cards and Record Numbers (p. 466)
‡Data Output: Writing High-Frequency Data to Memory Cards (p. 205)
‡File-System Errors (p. 389)
‡Data Storage Devices — List (p. 653)
‡Data-File Format Examples (p. 379)
‡Data Storage Drives Table (p. 373)
Caution Observe the following precautions when using memory cards:
x
x
x
x
Before installing a memory card, turn off power to the CR1000.
Before removing a card from the card slot, disable it by pressing the Eject
button, wait for the green light, and then turn CR1000 power off.
Do not remove a memory card while the drive is active or data corruption and
damage the card may result.
Prevent data loss by collecting data before sending a program from the
memory card to the CR1000. Sending a program from the card to the
CR1000 often erases all data.
Data stored on a memory card are collected to a PC through a telecommunication
link with the CR1000 or by removing the card and collecting it directly using a
third-party adapter on a PC.
89
Section 5. System Overview
Telecommunications
The CR1000 accesses data on the card as needed to fill data-collection requests
initiated with the datalogger support software Collect (p. 509) command. An
alternative, if care is taken, is to collect data in binary form. Binary data are
collected using the datalogger support software File Control | Retrieve (p. 515)
command. Before collecting data this way, stop the CR1000 program to ensure
data are not written to the card while data are retrieved, or data will be corrupted.
Direct with Adapter to PC
Data transfer is much faster through an adapter than through a
telecommunications link. This speed difference is especially noticeable with large
files.
The format of data files collected with a PC with an adapter is different than the
standard Campbell Scientific data file formats. See section Data-File Format
Examples (p. 379) for more information. Data files can be converted to a Campbell
Scientific format using CardConvert (p. 509) software.
5.3.9.5 Data-File Formats in CR1000 Memory
Routine CR1000 operations store data in binary data tables. However, when the
TableFile() instruction is used, data are also stored in one of several formats in
discrete text files in internal or external memory. See Data Storage — On-board
(p. 374) for more information on the use of the TableFile() instruction.
5.3.9.6 Data Format on Computer
CR1000 data stored on a PC with datalogger support software (p. 654) are formatted
as either ASCII or binary depending on the file type selected in the support
software. Consult the software manual for details on available data-file formats.
5.3.10 Alternate Telecommunications — Overview
Related Topics:
‡Alternate Telecommunications — Overview (p. 90)
‡Alternate Telecommunications — Details (p. 407)
The CR1000 communicates with external devices to receive programs, send data,
or act in concert with a network. The primary communication protocol is PakBus
(p. 522). Other telecommunication protocols are supported, including Web API (p.
423), Modbus (p. 411), and DNP3 (p. 408). Refer to the section Specifications (p. 97) for a
complete list of supported protocols. The appendix Data Retrieval and
Telecommunications — Peripherals Lists (p. 651) lists peripheral communication
devices available from Campbell Scientific.
Keyboard displays also communicate with the CR1000. See Keyboard Display —
Overview (p. 83) for more information.
90
Section 5. System Overview
5.3.10.1 Modbus
Related Topics:
‡Modbus — Overview (p. 91)
‡Modbus — Details (p. 411)
The CR1000 supports Modbus master and Modbus slave communications for
inclusion in Modbus SCADA networks. Modbus is a widely used SCADA
communication protocol that facilitates exchange of information and data between
computers / HMI software, instruments (RTUs) and Modbus-compatible sensors.
The CR1000 communicates with Modbus over RS-232, RS-485 (with a RS-232 to
RS-485 adapter), and TCP.
Modbus systems consist of a master (PC), RTU / PLC slaves, field instruments
(sensors), and the communication-network hardware. The communication port,
baud rate, data bits, stop bits, and parity are set in the Modbus driver of the master
and / or the slaves. The Modbus standard has two communication modes, RTU
and ASCII. However, CR1000s communicate in RTU mode exclusively.
Field instruments can be queried by the CR1000. Because Modbus has a set
command structure, programming the CR1000 to get data from field instruments
is much simpler than from serial sensors. Because Modbus uses a common bus
and addresses each node, field instruments are effectively multiplexed to a
CR1000 without additional hardware.
5.3.10.2 DNP3 — Overview
Related Topics:
‡DNP3 — Overview (p. 91)
‡DNP3 — Details (p. 408)
The CR1000 supports DNP3 slave communications for inclusion in DNP3
SCADA networks.
5.3.10.3 TCP/IP — Overview
Related Topics:
‡TCP/IP — Overview (p. 91)
‡TCP/IP — Details (p. 423)
‡TCP/IP — Instructions (p. 593)
‡TCP/IP Links — List (p. 652)
The CR1000 supports the following TCP/IP protocols:
x
x
x
x
x
x
x
x
x
DHCP
DNS
FTP
HTML
HTTP
Micro-serial server
NTCIP
NTP
91
Section 5. System Overview
x
x
x
x
x
x
x
x
PakBus over TCP/IP
Ping
POP3
SMTP
SNMP
Telnet
Web API
XML
5.3.11 Security — Overview
Related Topics:
‡Security — Overview (p. 92)
‡Security — Details (p. 467)
The CR1000 is supplied void of active security measures. By default, RS-232,
Telnet, FTP and HTTP services, all of which give high level access to CR1000
data and CRBasic programs, are enabled without password protection.
You may wish to secure your CR1000 from mistakes or tampering. The
following may be reasons to concern yourself with datalogger security:
x
x
x
Collection of sensitive data
Operation of critical systems
Networks accessible by many individuals
If you are concerned about security, especially TCP/IP threats, you should send
the latest operating system (p. 86) to the CR1000, disable un-used services, and
secure those that are used. Security actions to take may include the following:
x
x
x
x
x
x
x
x
x
Set passcode lockouts
Set PakBus/TCP password
Set FTP username and password
Set AES-128 PakBus encryption key
Set .csipasswd file for securing HTTP and web API
Track signatures
Encrypt program files if they contain sensitive information
Hide program files for extra protection
Secure the physical CR1000 and power supply under lock and key
Note All security features can be subverted through physical access to the
CR1000. If absolute security is a requirement, the physical CR1000 must be kept
in a secure location.
Related Topics
‡Auto Calibration — Overview (p. 92)
‡Auto Calibration — Details (p. 344)
‡Auto-Calibration — Errors (p. 490)
‡Offset Voltage Compensation (p. 323)
‡Factory Calibration (p. 94)
‡Factory Calibration or Repair Procedure (p. 476)
The CR1000 auto-calibrates to compensate for changes caused by changing
92
Section 5. System Overview
operating temperatures and aging. With auto-calibration disabled, measurement
accuracy over the operational temperature range is specified as less accurate by a
factor of 10. That is, over the extended temperature range of –40 °C to 85 qC, the
accuracy specification of r0.12% of reading can degrade to r1% of reading with
auto-calibration disabled. If the temperature of the CR1000 remains the same,
there is little calibration drift if auto-calibration is disabled. Auto-calibration can
become disabled when the scan rate is too small. It can be disabled by the
CRBasic program when using the Calibrate() instruction.
Note The CR1000 is equipped with an internal voltage reference used for
calibration. The voltage reference should be periodically checked and recalibrated by Campbell Scientific for applications with critical analog voltage
measurement requirements. A minimum two-year recalibration cycle is
recommended.
Unless a Calibrate() instruction is present, the CR1000 automatically autocalibrates during spare time in the background as an automatic slow sequence (p.
157) with a segment of the calibration occurring every four seconds. If there is
insufficient time to do the background calibration because of a scan-consuming
user program, the CR1000 will display the following warning at compile time:
Warning: Background calibration is disabled.
5.3.12 Maintenance — Overview
Related Topics:
‡Maintenance — Overview (p. 93)
‡Maintenance — Details (p. 473)
With reasonable care, the CR1000 should give many years of reliable service.
5.3.12.1 Protection from Moisture — Overview
Protection from Moisture — Overview (p. 93)
Protection from Moisture — Details (p. 99)
Protection from Moisture — Products (p. 660)
The CR1000 and most of its peripherals must be protected from moisture.
Moisture in the electronics will seriously damage, and probably render unrepairable, the CR1000. Water can come from flooding or sprinkler irrigation, but
most often comes as condensation. In most cases, protection from water is easily
accomplished by placing the CR1000 in a weather-tight enclosure with desiccant
and elevating the enclosure above the ground. The CR1000 is shipped with
internal desiccant packs to reduce humidity. Desiccant in enclosures should be
changed periodically.
Note Do not completely seal the enclosure if lead-acid batteries are present;
hydrogen gas generated by the batteries may build up to an explosive
concentration.
Refer to Enclosures List (p. 659) for information on available weather-tight
enclosures.
93
Section 5. System Overview
5.3.12.2 Protection from Voltage Transients
Read More See Grounding (p. 105).
The CR1000 must be grounded to minimize the risk of damage by voltage
transients associated with power surges and lightning-induced transients. Earth
grounding is required to form a complete circuit for voltage-clamping devices
internal to the CR1000. Refer to the appendix Transient-Voltage Suppressors List
(p. 648) for information on available surge-protection devices.
5.3.12.3 Factory Calibration
Related Topics
‡Auto Calibration — Overview (p. 92)
‡Auto Calibration — Details (p. 344)
‡Auto-Calibration — Errors (p. 490)
‡Offset Voltage Compensation (p. 323)
‡Factory Calibration (p. 94)
‡Factory Calibration or Repair Procedure (p. 476)
The CR1000 uses an internal voltage reference to routinely calibrate itself.
Campbell Scientific recommends factory recalibration every two years. If
calibration services are required, refer to the section entitled Assistance (p. 5) at the
front of this manual.
5.3.12.4 Internal Battery — Details
Related Topics:
‡Internal Battery — Quickstart (p. 45)
‡Internal Battery — Details (p. 94)
Warning Misuse or improper installation of the internal lithium battery can
cause severe injury. Fire, explosion, and severe burns can result. Do not recharge,
disassemble, heat above 100 °C (212 °F), solder directly to the cell, incinerate, or
expose contents to water. Dispose of spent lithium batteries properly.
The CR1000 contains a lithium battery that operates the clock and SRAM when
the CR1000 is not externally powered. In a CR1000 stored at room temperature,
the lithium battery should last approximately three years (less at temperature
extremes). If the CR1000 is continuously powered, the lithium cell should last
much longer. Internal lithium battery voltage can be monitored from the CR1000
Status table. Operating range of the battery is approximately 2.7 to 3.6 Vdc.
Replace the battery as directed in Replacing the Internal Battery (p. 473) when the
voltage is below 2.7 Vdc.
The lithium battery is not rechargeable. Its design is one of the safest available
and uses lithium thionyl chloride technology. Maximum discharge current is
limited to a few mA. It is protected from discharging excessive current to the
internal circuits (there is no direct path outside) with a 100 ohm resistor. The
design is UL listed. See:
http://www.tadiran-batterie.de/download/eng/LBR06Eng.pdf.
94
Section 5. System Overview
The battery is rated from -55 °C up to 85 °C.
5.4
Datalogger Support Software — Overview
Reading List:
‡Datalogger Support Software — Quickstart (p. 46)
‡Datalogger Support Software — Overview (p. 95)
‡Datalogger Support Software — Details (p. 450)
‡Datalogger Support Software — Lists (p. 654)
Datalogger support software are PC or Linux software available from Campbell
Scientific that facilitate communication between the computer and the CR1000.
A wide array of software are available, but most of the heavy lifting gets done by
the following:
x
x
x
x
x
Short Cut Program Generator for Windows (SCWin) — Short Cut is used to
write simple CRBasic programs without the need to learn the CRBasic
programming language. Short Cut is an easy-to-use wizard that steps you
through the program building process.
PC200W Datalogger Starter Software for Windows — Supports only direct
serial connection to the CR1000 with hardwire or spread-spectrum radio. It
supports sending a CRBasic program, data collection, and setting the CR1000
clock. PC200W is available at no charge at www.campbellsci.com/downloads
(http://www.campbellsci.com/downloads).
LoggerLink Mobile Apps — Simple tool that allows an iOS or Android
device to communicate with IP-enabled CR1000s. It includes most PC200W
functionality.
PC400 Datalogger Support Software — Includes PC200W functions,
CRBasic Editor, and supports all telecommunication modes (except satellite)
in attended mode.
LoggerNet Datalogger Support Software — Includes all PC400 functions and
supports all telecommunication options (except satellite) in unattended mode.
It also includes many enhancements such as graphical data displays.
Note More information about software available from Campbell Scientific can be
found at www.campbellsci.com http://www.campbellsci.com. Please consult with
a Campbell Scientific application engineer for a software recommendation to fit a
specific application.
95
6.
Specifications
1.1 -- 8 10 30
ZϭϬϬϬƐƉĞĐŝĨŝĐĂƚŝŽŶƐĂƌĞǀĂůŝĚĨƌŽŵ൞ϮϱΣƚŽϱϬΣŝŶŶŽŶ-condensing environments unless otherwise specified. Recalibration is recommended every two years. Critical specifications and system
configurations should be confirmed with a Campbell Scientific application engineer before purchase.
2.0 -- 8 10 30
3.5.0 -- 8 10 30
7.0 -- 8 10 30
PROGRAM EXECUTION RATE
10 ms to one day at 10 ms increments
ANALOG INPUTS (SE 1–16, DIFF 1–8)
Eight differential (DIFF) or 16 single-ended (SE) individually
configured input channels. Channel expansion provided by
optional analog multiplexers.
RANGES and RESOLUTION: With reference to the following table,
basic resolution (Basic Res) is the resolution of a single A/D (p.
507) conversion. A DIFF measurement with input reversal has
better (finer) resolution by twice than Basic Res.
DIFF
Basic
Range (mV)1
ZĞƐ;ʅsͿ2
ZĞƐ;ʅsͿ
±5000
667
1333
±2500
333
667
±250
33.3
66.7
±25
3.33
6.7
±7.5
1.0
2.0
±2.5
0.33
0.67
1ZĂŶŐĞŽǀĞƌŚĞĂĚŽĨуϵйŽŶĂůůƌĂŶŐĞƐŐƵĂƌĂŶƚĞĞƐĨƵůů-scale
voltage will not cause over-range.
2Resolution of DIFF measurements with input reversal.
PERIOD AVERAGE
Any of the 16 SE analog inputs can be used for period
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resolution is 136 ns divided by the specified number of cycles
to be measured.
INPUT AMPLITUDE AND FREQUENCY:
Input
Signal
Min
VoltWĞĂŬ-WĞĂŬ
Pulse
Max
age
Range
Min
Max
Width
Freq
Gain
Code
mV6
V7
ђƐ
Ŭ,nj8
DIGITAL I/O PORTS (C 1–8)
Eight ports software selectable as binary inputs or control
ŽƵƚƉƵƚƐ͘WƌŽǀŝĚĞŽŶͬŽĨĨ͕ƉƵůƐĞǁŝĚƚŚŵŽĚƵůĂƚŝŽŶ͕ĞĚŐĞƚŝŵŝŶŐ͕
ƐƵďƌŽƵƚŝŶĞŝŶƚĞƌƌƵƉƚƐͬǁĂŬĞƵƉ͕ƐǁŝƚĐŚ-closure pulse counting,
high-frequency pulse counting, asynchronous communications
(UARTs), and SDI-12 communications. SDM communications are
also supported.
>Kt&ZYhEzDKDy͗фϭŬ,nj
,/',&ZYhEzDKDy͗ϰϬϬŬ,nj
^t/d,->K^hZ&ZYhEzDy͗ϭϱϬ,nj
EDGE-TIMING RESOLUTION: 540 ns
OUTPUT VOLTAGES (no load): high 5.0 V ±0.1 V; low < 0.1 V
KhdWhdZ^/^dE͗ϯϯϬɏ
INPUT STATE: high 3.8 to 16 V; low -8.0 to 1.2 V
/EWhd,z^dZ/^/^͗ϭ͘ϰs
INPUT RESISTANCE:
ϭϬϬŬɏǁŝƚŚŝŶƉƵƚƐфϲ͘ϮsĚĐ
ϮϮϬɏǁŝƚŚŝŶƉƵƚƐшϲ͘ϮsĚĐ
^Z/>s/ͬZ^-232 SUPPORT: 0 to 5 Vdc UART
2.1 -- 8 10 30
3.0 -- 8 10 30
3.0.1 -- 8 10 30
3.1.0 -- 8 10 30
3.1.1 -- 8 10
3.5.0a -- 8 10 30
3.5.1 -- 8 10
7.0.1 -- 8 10 30
7.1 -- 8 10 30
7.2 -- 8 10 30
7.3 -- 8 10 30
7.4 -- 8 10 30
7.5 -- 8 10 30
1
10
33
100
mV250
mV25
mV7_5
mV2_5
500
10
5
2
10
2
2
2
2.5
10
62
100
200
50
8
5
6Signal
to be centered around Threshold (see PeriodAvg()
instruction).
7Signal to be centered around ground.
8dŚĞŵĂdžŝŵƵŵĨƌĞƋƵĞŶĐLJсϭͬ;ƚǁŝĐĞŵŝŶŝŵƵŵƉƵůƐĞǁŝĚƚŚͿ
7.6 -- 8 10 30
7.7 -- 8 10 30
7.8 -- 8 10 30
7.9 -- 8 10 30
7.10 -- 8 10 30
7.12 -- 8 10 30
StITCHED 1Ϯ Vdc (St-1Ϯ)
One independent 12 Vdc unregulated terminal switched on and
off under program control. Thermal fuse hold current = 900 mA
at 20°C, 650 mA at 50°C, and 360 mA at 85°C.
CE COMPLIANCE
^dEZ;^ͿdKt,/,KE&KZD/dz/^>Z͗
IEC61326:2002
3Accuracy does not include sensor and measurement noise.
COMMUNICATION
Offset definitions:
RS-232 PORTS:
KĨĨƐĞƚсϭ͘ϱdžĂƐŝĐZĞƐнϭ͘Ϭђs;ĨŽƌ/&&ŵĞĂƐƵƌĞŵĞŶƚǁͬŝŶƉƵƚ
DCE nine-pin: (not electrically isolated) for computer connection
RATIOMETRIC MEASUREMENT ACCURACY9,11
reversal)
or connection of modems not manufactured by Campbell
Note Important assumptions outlined in footnote 9:
KĨĨƐĞƚсϯdžĂƐŝĐZĞƐнϮ͘Ϭђs;ĨŽƌ/&&ŵĞĂƐƵƌĞŵĞŶƚǁͬŽŝŶƉƵƚ
Scientific.
ц;Ϭ͘ϬϰйŽĨsŽůƚĂŐĞDĞĂƐƵƌĞŵĞŶƚнKĨĨƐĞƚ12)
reversal)
KDϭƚŽKDϰ͗ĨŽƵƌŝŶĚĞƉĞŶĚĞŶƚddžͬZdžƉĂŝƌƐŽŶĐŽŶƚƌŽůƉŽƌƚƐ
Offset = 3 x BasiĐZĞƐнϯ͘Ϭђs;ĨŽƌ^ŵĞĂƐƵƌĞŵĞŶƚͿ
9Accuracy specification assumes excitation reversal for
(non-isolated); 0 to 5 Vdc UART
ANALOG MEASUREMENT SPEED:
Baud Rate: selectable frŽŵϯϬϬďƉƐƚŽϭϭϱ͘ϮŬďƉƐ͘
excitation voltages < 10001000 mV. Assumption does not
4
Default
Format: eight data bits; one stop bits; no parity.
---Total Time --include bridge resistor errors and sensor and measurement
Optional Formats: seven data bits; two stop bits; odd, even
noise.
InteSE
DIFF
parity.
gration
Intewith
with
11ƐƚŝŵĂƚĞĚĂĐĐƵƌĂĐLJ͕ѐy;ǁŚĞƌĞyŝƐǀĂůƵĞƌĞƚƵƌŶĞĚĨƌŽŵ
^/ͬKWKZd͗/ŶƚĞƌĨĂĐĞǁŝƚŚƚĞůĞĐŽŵŵƵŶŝĐĂƚŝŽŶƉĞƌŝƉŚĞƌĂůƐ
Type
gration
Settling
no
Input
manufactured by Campbell Scientific.
measurement with Multiplier =1, Offset = 0):
Code
Time
Time
Rev
Rev
SDI-12: Digital control ports C1, C3, C5, C7 are individually
BRHalf() /ŶƐƚƌƵĐƚŝŽŶ͗ѐyсѐsϭͬVX.
ϮϱϬ
ϮϱϬђƐ
450 ђƐ
уϭŵƐ
уϭϮŵƐ
BRFull() Instruction: ѐyсϭϬϬϬdžѐsϭͬVX͕ĞdžƉƌĞƐƐĞĚĂƐŵsͻs-1. configurable and meet SDI-12 Standard v. 1.3 for datalogger
5
_60Hz
16.67 ms
3 ms
уϮϬŵƐ
уϰϬŵƐ
mode. Up to ten SDI-12 sensors are supported per port.
Note ѐs1 is calculated from the ratiometric measurement
_ϱ0Hz5
20.00 ms
3 ms
уϮϱŵƐ
уϱϬŵƐ
accuracy. See manual section Resistance Measurements (p.
WZ/W,Z>WKZd͗ϰϬ-pin interface for attaching CompactFlash
337) for more information.
or Ethernet peripherals.
12Offset definitions:
4/ŶĐůƵĚĞƐϮϱϬʅƐĨŽƌĐŽŶǀĞƌƐŝŽŶƚŽĞŶŐŝŶĞĞƌŝŶŐƵŶŝƚƐ͘
WZKdKK>^^hWWKZd͗WĂŬƵƐ͕^-ϭϮϴŶĐƌLJƉƚĞĚWĂŬƵƐ͕
KĨĨƐĞƚсϭ͘ϱdžĂƐŝĐZĞƐнϭ͘Ϭђs;ĨŽƌ/&&ŵĞĂƐƵƌĞŵĞŶƚǁͬ
5AC line noise filter
DŽĚďƵƐ͕EWϯ͕&dW͕,ddW͕yD>͕,dD>͕WKWϯ͕^DdW͕dĞůŶĞƚ͕
input reversal)
NTCIP, NTP, web API, SDI-12, SDM.
KĨĨƐĞƚсϯdžĂƐŝĐZĞƐнϮ͘Ϭђs;ĨŽƌ/&&ŵĞĂƐƵƌĞŵĞŶƚ ǁͬŽ
SYSTEM
INPUT-NOISE VOLTAGE: For DIFF measurements with input
input reversal)
PROCESSOR:
RenesaƐ,ϴ^ϮϯϮϮ;ϭϲ-bit CPU with 32-bit internal
reversal on ±2.5 mV input range (digital resolution dominates for
KĨĨƐĞƚсϯdžĂƐŝĐZĞƐнϯ͘Ϭђs;ĨŽƌ^ŵĞĂƐƵƌĞŵĞŶƚͿ
ĐŽƌĞƌƵŶŶŝŶŐĂƚϳ͘ϯD,njͿ
higher ranges):
Note Excitation reversal reduces offsets by a factor of two.
MEMORY: 2 MB of flash for operating system; 4 MB of batteryϮϱϬʅƐ/ŶƚĞŐƌĂƚŝŽŶ͗Ϭ͘ϯϰʅsZD^
PULSE COUNTERS (P 1–Ϯ)
ďĂĐŬĞĚ^ZDĨŽƌWh͕ZĂƐŝĐƉƌŽŐƌĂŵƐ͕ĂŶĚĚĂƚĂ͘
ϱϬͬϲϬ,nj/ŶƚĞŐƌĂƚŝŽŶ͗Ϭ͘ϭϵʅsZD^
Two inputs individually selectable for switch closure, highREAL-TIME CLOCK ACCURACY: ±3 min. per year. Correction via
INPUT LIMITS: ±5 Vdc
frequency pulse, or low-level ac. Independent 24-bit counters
GPS optional.
DC COMMON-MODE REJECTION: >100 dB
for each input.
RTC CLOCK RESOLUTION: 10 ms
NORMAL-DKZ:d/KE͗ϳϬĚΛϲϬ,njǁŚĞŶƵƐŝŶŐϲϬ,nj
MAXIMUM COUNTS PER SCAN: 16.7 x 106
SYSTEM POWER REQUIREMENTS
rejection
^t/d,-CLOSURE MODE:
VOLTAGE: 9.6 to 16 Vdc
/EWhdsK>d'ZE'tͬKD^hZDEdKZZhWd/KE͗цϴ͘ϲ
Minimum Switch Closed Time: 5 ms
Vdc max.
/EdZE>ddZz͗ϭϮϬϬŵŚƌůŝƚŚŝƵŵďĂƚƚĞƌLJĨŽƌĐůŽĐŬĂŶĚ
Minimum Switch Open Time: 6 ms
^ZDďĂĐŬƵƉ͘dLJƉŝĐĂůůLJƉƌŽǀŝĚĞƐƚŚƌĞĞLJĞĂƌƐŽĨďĂĐŬ-up.
SUSTAINED-/EWhdsK>d'tͬKD'͗цϭϲsĚĐŵĂdž
Max. Bounce Time: 1 ms open without being counted
INPUT CURRENT: ±1 nA typical, ±6 nA max. @ 50°C; ±90 nA @ 85°C ,/',-FREQUENCY PULSE MODE:
ydZE>ddZ/^͗KƉƚŝŽŶĂůϭϮsĚĐŶŽŵŝŶĂůĂůŬĂůŝŶĞĂŶĚ
/EWhdZ^/^dE͗ϮϬ'ɏƚLJƉŝĐĂů
Maximum-/ŶƉƵƚ&ƌĞƋƵĞŶĐLJ͗ϮϱϬŬ,nj
rechargeable available. Power connection is reverse polarity
ACCURACY OF BUILT-/EZ&ZE:hEd/KEd,ZD/^dKZ;ĨŽƌ
Maximum-Input Voltage: ±20 V
protected.
thermocouple measurements):
Voltage Thresholds: Count upon transition from below 0.9 V to
TYPICAL
CURRENT DRAIN at 12 Vdc:
±0.3°C, -25° to 50°C
ĂďŽǀĞϮ͘ϮsĂĨƚĞƌŝŶƉƵƚĨŝůƚĞƌǁŝƚŚϭ͘ϮʅƐƚŝŵĞĐŽŶƐƚĂŶƚ͘
Sleep Mode: 0.7 mA typical; 0.9 mA maximum
±0.8°C, -55° to 85°C (-XT only)
LOW-LEVEL AC MODE: Internal ac coupling removes dc offsets
ϭ,nj^ĂŵƉůĞZĂƚĞ;ŽŶĞĨĂƐƚ^ŵĞĂƐ͘Ϳŵ
ANALOG OUTPUTS (VX 1–3)
up to ±0.5 Vdc.
ϭϬϬ,nj^ĂŵƉůĞZĂƚĞ;ŽŶĞĨĂƐƚ^ŵĞĂƐ͘Ϳ͗ϭϲŵ
/ŶƉƵƚ,LJƐƚĞƌĞƐŝƐ͗ϭϮŵsZD^Λϭ,nj
ϭϬϬ,nj^ĂŵƉůĞZĂƚĞ;ŽŶĞĨĂƐƚ^ŵĞĂƐ͘ǁŝƚŚZ^-232
Maximum ac-Input Voltage: ±20 V
Three switched voltage outputs sequentially active only during
communications): 28 mA
Minimum ac-Input Voltage:
measurement.
ĐƚŝǀĞĞdžƚĞƌŶĂůŬĞLJďŽĂƌĚĚŝƐƉůĂLJĂĚĚƐϳŵ;ϭϬϬŵǁŝƚŚ
Sine wave (mV RMS)
ZĂŶŐĞ;,njͿ
ďĂĐŬůŝŐŚƚŽŶͿ͘
RANGES AND RESOLUTION:
20
1.0 to 20
PHYSICAL
200
0.5 to 200
Current
DIMENSIONS: 239 x 102 x 61 mm (9.4 x 4.0 x 2.4 in.) ; additional
2000
0.3 to 10,000
ResoluSource
clearance required for cables and leads.
5000
0.3 to 20,000
Channel
Range
tion
ͬ^ŝŶŬ
D^^ͬt/',d͗ϭ͘ϬŬŐͬϮ͘ϭůďƐ
DIGITAL I/O PORTS (C 1–8)
(VX 1–3)
±2.5 Vdc
0.67 mV
±25 mA
WARRANTY
Eight ports software selectable as binary inputs or control
Warranty is stated in the published price list and in opening
ANALOG OUTPUT ACCURACY (VX):
ŽƵƚƉƵƚƐ͘WƌŽǀŝĚĞŽŶͬŽĨĨ͕Ɖulse width modulation, edge timing,
ц;Ϭ͘ϬϲйŽĨƐĞƚƚŝŶŐнϬ͘ϴŵs͕ϬΣƚŽϰϬΣ
ƐƵďƌŽƵƚŝŶĞŝŶƚĞƌƌƵƉƚƐͬǁĂŬĞƵƉ͕ƐǁŝƚĐŚ-closure pulse counting, pages of this and other user manuals.
ц;Ϭ͘ϭϮйŽĨƐĞƚƚŝŶŐнϬ͘ϴŵs͕-25° to 50°C
high-frequency pulse counting, asynchronous communications
ц;Ϭ͘ϭϴйŽĨƐĞƚƚŝŶŐнϬ͘ϴŵs͕-55° to 85°C (-XT only)
(UARTs), and SDI-12 communications. SDM communications
are also supported.
VX FREQUENCY SWEEP FUNCTION: Switched outputs provide a
programmable swept frequency, 0 to 2500 mV square waves for
exciting vibrating wire transducers.
ĨŽƌϱϬйŽĨĚƵƚLJĐLJĐůĞƐŝŐŶĂůƐ͘
RATIOMETRIC MEASUREMENTS
MEASUREMENT TYPES: The CR1000 provides ratiometric
resistance measurements using voltage excitation. Three
switched voltage excitation outputs are available for
measurement of four- and six-wire full bridges, and two-,
three-, and four-wire half bridges. Optional excitation polarity
ƌĞǀĞƌƐĂůŵŝŶŝŵŝnjĞƐĚĐĞƌƌŽƌƐ͘
5.0 -- 8 10 30
3.2 -- 8 10
ANALOG INPUT ACCURACY3:
ц;Ϭ͘ϬϲйŽĨƌĞĂĚŝŶŐнŽĨĨƐĞƚ3), 0° to 40°C
ц;Ϭ͘ϭϮйŽĨƌĞĂĚŝŶŐнŽĨĨƐĞƚ3), -25° to 50°C
ц;Ϭ͘ϭϴйŽĨƌĞĂĚŝŶŐнŽĨĨƐĞƚ3), -55° to 85°C (-XT only)
3.2.1 -- 8 10 30
5.1 -- 8 10
8.0 -- 8 10 30
8.1 -- 8 10 30
9.0 -- 8 10 30
9.1 -- 8 10 30
5.2 -- 8 10
5.2.1 -- 8 10 30
3.3 -- 8 10 30
3.3.1 -- 8 10
9.2 -- 8 10 30
9.3 -- 8 10 30
9.4 -- 30
9.5 -- 8 10 30
10.0 -- 8 10 30
3.4 -- 8 10 30
3.4.1 -- 8 10 30
10.1 -- 8 10 30
10.2 -- 8 10 30
6.0 -- 8 10 30
6.0.1 -- 8 10 30
10.3 -- 8 10 30
3.4.2 -- 8 10 30
3.4.3 -- 8 10 30
10.4 -- 8 10 30
3.4.4 -- 8 10 30
6.1 -- 8 10 30
11.0 -- 8 10 30
6.2 -- 8 10 30
11.1 -- 8 10 30
3.4.5 -- 8 10 30
11.2 -- 8 10
3.4.6 -- 8 10 30
3.4.7 -- 8 10 30
6.3 -- 8 10 30
11.3 -- 8 10 30
3.4.8 -- 8 10 30
3.4.9 -- 8 10 30
11.4 -- 8 10 30
6.4 -- 8 10 30
4.0 -- 8 10 30
4.0.1 -- 10
6.4.1 -- 8 10 30
4.0.2 -- 8 10 30
12.0 -- 8 10 30
4.1 -- 8 10
12.1
12.2
7.0 -- 8 10 30
13.0
7.0.1 -- 8 10 30
4.2 -- 8 10
13.1
4.4 -- 8 10 30
97
98
7.
Installation
Reading List
‡Quickstart (p. 41)
‡Specifications (p. 97)
‡Installation (p. 99)
‡Operation (p. 303)
7.1
Protection from Moisture — Details
Protection from Moisture — Overview (p. 93)
Protection from Moisture — Details (p. 99)
Protection from Moisture — Products (p. 660)
When humidity levels reach the dew point, condensation occurs and damage to
CR1000 electronics can result. Effective humidity control is the responsibility of
the user.
The CR1000 module is protected by a packet of silica gel desiccant, which is
installed at the factory. This packet is replaced whenever the CR1000 is repaired
at Campbell Scientific. The module should not normally be opened except to
replace the internal lithium battery.
Adequate desiccant should be placed in the instrumentation enclosure to provide
added protection.
7.2
Temperature Range
The CR1000 is designed to operate reliably from –40 to 75 °C (–55 °C to 85 °C,
optional) in non-condensing environments.
7.3
Enclosures
Enclosures — Details (p. 99)
Enclosures — Products (p. 659)
Illustrated in figure Enclosure (p. 100) is the typical use of enclosures available from
Campbell Scientific designed for housing the CR1000. This style of enclosure is
classified as NEMA 4X (watertight, dust-tight, corrosion-resistant, indoor and
outdoor use). Enclosures have back plates to which are mounted the CR1000
datalogger and associated peripherals. Back plates are perforated on one-inch
centers with a grid of holes that are lined as needed with anchoring nylon inserts.
The CR1000 base has mounting holes (some models may be shipped with rubber
inserts in these holes) through which small screws are inserted into the nylon
anchors. Remove rubber inserts, if any, to access the mounting holes. Screws
and nylon anchors are supplied in a kit that is included with the enclosure.
99
Section 7. Installation
Figure 31. Enclosure
7.4
Power Supplies — Details
Related Topics:
‡3RZHU6XSSOLHV— Specifications
‡Power Supplies — Quickstart (p. 44)
‡Power Supplies — Overview (p. 85)
‡Power Supplies — Details (p. 100)
‡Power Supplies — Products (p. 657)
‡Power Sources (p. 101)
‡Troubleshooting — Power Supplies (p. 494)
Reliable power is the foundation of a reliable data-acquisition system. When
designing a power supply, consideration should be made regarding worst-case
power requirements and environmental extremes. For example, the power
requirement of a weather station may be substantially higher during extreme cold,
while at the same time, the extreme cold constricts the power available from the
power supply.
The CR1000 is internally protected against accidental polarity reversal on the
power inputs.
The CR1000 has a modest-input power requirement. For example, in low-power
applications, it can operate for several months on non-rechargeable batteries.
Power systems for longer-term remote applications typically consist of a charging
source, a charge controller, and a rechargeable battery. When ac line power is
available, a Vac-to-Vac or Vac-to-Vdc wall adapter, a peripheral charging
regulator, and a rechargeable battery can be used to construct a UPS (un-
100
Section 7. Installation
interruptible power supply).
Contact a Campbell Scientific application engineer if assistance in selecting a
power supply is needed, particularly with applications in extreme environments.
7.4.1
CR1000 Power Requirement
The CR1000 is operable with power from 9.6 to 16 Vdc applied at the POWER
IN terminals of the green connector on the face of the wiring panel.
The CR1000 is internally protected against accidental polarity reversal on the
power inputs. A transient voltage suppressor (TVS) diode at the POWER IN 12V
terminals provides protection from intermittent high voltages by clamping these
transients to within the range of 19 to 21 V . Sustained input voltages in excess of
19 V, can damage the TVS diode.
Caution Voltage levels at the 12V and switched SW12 terminals, and pin 8 on
the CS I/O port, are tied closely to the voltage levels of the main power supply.
For example, if the power received at the POWER IN 12V and G terminals is 16
Vdc, the 12V and SW12 terminals, and pin 8 on the CS I/O port, will supply 16
Vdc to a connected peripheral. If the connected peripheral or sensor is not
designed for that voltage level, it may be damaged.
7.4.2
Calculating Power Consumption
Read More Power Supplies — Overview (p. 85).
System operating time for batteries can be determined by dividing the battery
capacity (ampere-hours) by the average system current drain (amperes). The
CR1000 typically has a quiescent current drain of 0.5 mA (with display off) 0.6
mA with a 1 Hz sample rate, and >10 mA with a 100 Hz scan rate. When the
CR1000KD Keyboard Display is active, an additional 7 mA is added to the
current drain while enabling the backlight for the display adds 100 mA.
7.4.3
Power Sources
Related Topics:
‡3RZHU6XSSOLHV— Specifications
‡Power Supplies — Quickstart (p. 44)
‡Power Supplies — Overview (p. 85)
‡Power Supplies — Details (p. 100)
‡Power Supplies — Products (p. 657)
‡Power Sources (p. 101)
‡Troubleshooting — Power Supplies (p. 494)
Be aware that some Vac-to-Vdc power converters produce switching noise or ac
as an artifact of the ac-to-dc rectification process. Excessive
switching noise on the output side of a power supply can increase measurement
(p. 507) ripple
101
Section 7. Installation
noise, and so increase measurement error. Noise from grid or mains power also
may be transmitted through the transformer, or induced electro-magnetically from
nearby motors, heaters, or power lines.
High-quality power regulators typically reduce noise due to power regulation.
Using the optional 50 Hz or 60 Hz rejection arguments for CRBasic analog input
measurement instructions (see Sensor Support (p. 303) ) often improves rejection of
noise sourced from power mains. The CRBasic standard deviation instruction,
SDEV(), can be used to evaluate measurement noise.
The main power for the CR1000 is provided by an external-power supply.
7.4.3.1 Vehicle Power Connections
If a CR1000 is powered by a motor-vehicle power supply, a second power supply
may be needed. When starting the motor of the vehicle, battery voltage often
drops below the voltage required for datalogger operation. This may cause the
CR1000 to stop measurements until the voltage again equals or exceeds the lower
limit. A second supply can be provided to prevent measurement lapses during
vehicle starting. The figure Connecting CR1000 to Vehicle Power Supply (p. 102)
illustrates how a second power supply is connected to the CR1000. The diode OR
connection causes the supply with the largest voltage to power the CR1000 and
prevents the second backup supply from attempting to power the vehicle.
Figure 32. Connecting to Vehicle Power Supply
7.4.4
Uninterruptable Power Supply (UPS)
If external alkaline power is used, the alkaline battery pack is connected directly
to the POWER IN 12V and G terminals (9.6 to 16 Vdc).
A UPS (un-interruptible power supply) is often the best power source for longterm installations. An external UPS consists of a primary-power source, a
charging regulator external to the CR1000, and an external battery. The primary
power source, which is often a transformer, power converter, or solar panel,
connects to the charging regulator, as does a nominal 12 Vdc sealed rechargeable
battery. A third connection connects the charging regulator to the 12V and G
terminals of the POWER IN connector..
102
Section 7. Installation
7.4.5
External Power Supply Installation
When connecting external power to the CR1000, remove the green POWER IN
connector from the CR1000 face. Insert the positive lead into the green
connector, then insert the negative lead. Re-seat the green connector into the
CR1000. The CR1000 is internally protected against reversed external-power
polarity. Should this occur, correct the wire connections.
7.5
Switched Voltage Output — Details
Related Topics:
‡6ZLWFKHG9ROWDJH2XWSXW— Specifications
‡Switched Voltage Output — Overview (p. 78)
‡Switched Voltage Output — Details (p. 103)
‡PLC Control — Overview (p. 74)
‡PLC Control — Details (p. 244)
‡PLC Control Modules — Overview (p. 368)
‡PLC Control Modules — Lists (p. 648)
‡PLC Control — Instructions (p. 562)
The CR1000 wiring panel is a convenient power distribution device for powering
sensors and peripherals that require a 5 Vdc, or 12 Vdc source. It has two
continuous 12 Vdc terminals (12V), one program-controlled, switched, 12 Vdc
terminal (SW12), and one continuous 5 Vdc terminal (5V). SW12, 12V, and 5V
terminals limit current internally for protection against accidental short circuits.
Voltage on the 12V and SW12 terminals can vary widely and will fluctuate with
the dc supply used to power the CR1000, so be careful to match the datalogger
power supply to the requirements of the sensors. The 5V terminal is internally
regulated to within ±4%, which is good regulation as a power source, but typically
not adequate for bridge sensor excitation. Table Current Sourcing Limits (p. 103)
lists the current limits of 12V and 5V terminals. Greatly reduced output voltages
on these terminals may occur if the current limits are exceeded. See the section
Terminals Configured for Control (p. 368) for more information.
Table 5. Current Source and Sink Limits
1
Terminal
Limit
2
VX or EX (voltage excitation)
SW-12
3
±25 mA maximum
< 900 mA @ 20°C
< 630 mA @ 50°C
< 450 mA @ 70°C
4
12V + SW-12 (combined)
< 3.00 A @ 20°C
< 2.34 A @ 50°C
< 1.80 A @ 70°C
< 1.50 A @ 85°C
5
5V + CS I/O (combined)
< 200 mA
103
Section 7. Installation
Table 5. Current Source and Sink Limits
Terminal
1
1
Limit
"Source" is positive amperage; "sink" is negative amperage (–).
2
Exceeding current limits will cause voltage output to become unstable. Voltage should stabilize
once current is again reduced to within stated limits.
3
A polyfuse is used to limit power. Result of overload is a voltage drop. To reset, disconnect
and allow circuit to cool. Operating at the current limit is OK so long a a little fluctuation can be
tolerated.
4
Polyfuse protected. See footnote 3.
5
Current is limited by a current limiting circuit, which holds the current at the maximum by
dropping the voltage when the load is too great.
7.5.1
Switched-Voltage Excitation
Three switched, analog-output (excitation) terminals (VX1 to VX3) operate under
program control to provide ±2500 mV dc excitation. Check the accuracy
specification of terminals configured for exctitation in CR1000 Specifications (p.
97) to understand their limitations. Specifications are applicable only for loads not
exceeding ±25 mA.
Read More Table Current Source and Sink Limits (p. 103) has more information on
excitation load capacity.
CRBasic instructions that control voltage excitation include the following:
x
x
x
x
x
x
BrFull()
BrFull6W()
BrHalf()
BrHalf3W()
BrHalf4W()
ExciteV()
Note Square-wave ac excitation for use with polarizing bridge sensors is
configured with the RevEx parameter of the bridge instructions.
7.5.2
Continuous Regulated (5V Terminal)
The 5V terminal is regulated and remains near 5 Vdc (r4%) so long as the
CR1000 supply voltage remains above 9.6 Vdc. It is intended for power sensors
or devices requiring a 5 Vdc power supply. It is not intended as an excitation
source for bridge measurements. However, measurement of the 5V terminal
output, by means of jumpering to an analog input on the same CR1000), will
facilitate an accurate bridge measurement if 5V must be used.
Note Table Current Source and Sink Limits (p. 103) has more information on
excitation load capacity.
7.5.3
Continuous Unregulated Voltage (12V Terminal)
Use 12V terminals to continuously power devices that require 12 Vdc. Voltage
104
Section 7. Installation
on the 12V terminals will change with CR1000 supply voltage.
Caution Voltage levels at the 12V and switched SW12 terminals, and pin 8 on
the CS I/O port, are tied closely to the voltage levels of the main power supply.
For example, if the power received at the POWER IN 12V and G terminals is 16
Vdc, the 12V and SW12 terminals, and pin 8 on the CS I/O port, will supply 16
Vdc to a connected peripheral. If the connected peripheral or sensor is not
designed for that voltage level, it may be damaged.
7.5.4
Switched Unregulated Voltage (SW12 Terminal)
The SW12 terminal is often used to power devices such as sensors that require 12
Vdc during measurement. Current sourcing must be limited to 900 mA or less at
20 °C. See table Current Source and Sink Limits (p. 103). Voltage on a SW12
terminal will change with CR1000 supply voltage. Two CRBasic instructions,
SW12() and PortSet(), control the SW12 terminal. Each instruction is handled
differently by the CR1000. SW12() is a processing task. Use it when controlling
power to SDI-12 and serial sensors that use SDI12Recorder() or SerialIn()
instructions respectively. CRBasic programming using IF THEN constructs to
control SW12, such as when used for cell phone control, should also use the
SW12() instruction.
PortSet() is a measurement task instruction. Use it when powering analog input
sensors that need to be powered just prior to measurement.
A 12 Vdc switching circuit designed to be driven by a C terminal is available
from Campbell Scientific. It is listed in the appendix Relay Drivers — Products (p.
649).
Note SW12 terminal power is unregulated and can supply up to 900 mA at 20
°C. See table Current Source and Sink Limits (p. 103). A resettable polymeric fuse
protects against over-current. Reset is accomplished by removing the load or
turning off the SW12 terminal for several seconds.
The SW12 terminal may behave differently under pipeline (p. 152) and sequential (p.
See CRBasic Editor Help for more information.
153) modes.
7.6
Grounding
Grounding the CR1000 with its peripheral devices and sensors is critical in all
applications. Proper grounding will ensure maximum ESD (electrostatic
discharge) protection and measurement accuracy.
7.6.1
ESD Protection
Reading List:
‡ESD Protection (p. 105)
‡Lightening Protection (p. 107)
ESD (electrostatic discharge) can originate from several sources, the most
common and destructive being lightning strikes. Primary lightning strikes hit the
CR1000 or sensors directly. Secondary strikes induce a high voltage in power
lines or sensor wires.
105
Section 7. Installation
The primary devices for protection against ESD are gas-discharge tubes (GDT).
All critical inputs and outputs on the CR1000 are protected with GDTs or
transient voltage suppression diodes. GDTs fire at 150 V to allow current to be
diverted to the earth ground lug. To be effective, the earth ground lug must be
properly connected to earth (chassis) ground. As shown in figure Schematic of
Grounds (p. 107), signal grounds and power grounds have independent paths to the
earth-ground lug.
Communication ports are another path for transients. You should provide
communication paths, such as telephone or short-haul modem lines, with sparkgap protection. Spark-gap protection is usually an option with these products, so
request it when ordering. Spark gaps must be connected to either the earth ground
lug, the enclosure ground, or to the earth (chassis) ground.
A good earth (chassis) ground will minimize damage to the datalogger and
sensors by providing a low-resistance path around the system to a point of low
potential. Campbell Scientific recommends that all dataloggers be earth (chassis)
grounded. All components of the system (dataloggers, sensors, external power
supplies, mounts, housings, etc.) should be referenced to one common earth
(chassis) ground.
In the field, at a minimum, a proper earth ground will consist of a 6 to 8 foot
copper-sheathed grounding rod driven into the earth and connected to the large
brass ground lug on the wiring panel with a 12 AWG wire. In low-conductive
substrates, such as sand, very dry soil, ice, or rock, a single ground rod will
probably not provide an adequate earth ground. For these situations, search for
published literature on lightning protection or contact a qualified lightningprotection consultant.
In vehicle applications, the earth ground lug should be firmly attached to the
vehicle chassis with 12 AWG wire or larger.
In laboratory applications, locating a stable earth ground is challenging, but still
necessary. In older buildings, new Vac receptacles on older Vac wiring may
indicate that a safety ground exists when, in fact, the socket is not grounded. If a
safety ground does exist, good practice dictates the verification that it carries no
current. If the integrity of the Vac power ground is in doubt, also ground the
system through the building plumbing, or use another verified connection to earth
ground.
106
Section 7. Installation
Figure 33. Schematic of Grounds
7.6.1.1 Lightning Protection
Reading List:
‡ESD Protection (p. 105)
‡Lightening Protection (p. 107)
The most common and destructive ESDs are primary and secondary lightning
strikes. Primary lightning strikes hit instrumentation directly. Secondary strikes
induce voltage in power lines or wires connected to instrumentation. While
elaborate, expensive, and nearly infallible lightning protection systems are on the
market, Campbell Scientific, for many years, has employed a simple and
inexpensive design that protects most systems in most circumstances. The system
employs a lightening rod, metal mast, heavy-gage ground wire, and ground rod to
direct damaging current away from the CR1000. This system, however, not
infallible. Figure Lightning-Protection Scheme (p. 108) is a drawing of a typical
application of the system.
107
Section 7. Installation
Note Lightning strikes may damage or destroy the CR1000 and associated
sensors and power supplies.
In addition to protections discussed in , use of a simple lightning rod and lowresistance path to earth ground is adequate protection in many installations. .
Figure 34. Lightning-Protection Scheme
7.6.2
Single-Ended Measurement Reference
Low-level, single-ended voltage measurements (<200 mV) are sensitive to ground
potential fluctuation due to changing return currents from 12V, SW12, 5V, and
C1 – C8 terminals. The CR1000 grounding scheme is designed to minimize these
108
Section 7. Installation
fluctuations by separating signal grounds ( ) from power grounds (G). To take
advantage of this design, observe the following rules:
x
x
x
x
Connect grounds associated with 12V, SW12, 5V, and C1 – C8 terminals to
G terminals.
Connect excitation grounds to the nearest
terminal on the same terminal
block.
Connect the low side of single-ended sensors to the nearest
terminal on
the same terminal block.
Connect shield wires to the
terminal nearest the terminals to which the
sensor signal wires are connected.
Note Several ground wires can be connected to the same ground terminal.
If offset problems occur because of shield or ground leads with large current flow,
tying the problem leads into
terminals next to terminals configured for
excitation and pulse-count should help. Problem leads can also be tied directly to
the ground lug to minimize induced single-ended offset voltages.
7.6.3
Ground-Potential Differences
Because a single-ended measurement is referenced to CR1000 ground, any
difference in ground potential between the sensor and the CR1000 will result in a
measurement error. Differential measurements MUST be used when the input
ground is known to be at a different ground potential from CR1000 ground. See
the section Single-Ended Measurements — Details (p. 307) for more information.
Ground potential differences are a common problem when measuring full-bridge
sensors (strain gages, pressure transducers, etc), and when measuring
thermocouples in soil.
7.6.3.1 Soil Temperature Thermocouple
If the measuring junction of a thermocouple is not insulated when in soil or water,
and the potential of earth ground is, for example, 1 mV greater at the sensor than
at the point where the CR1000 is grounded, the measured voltage is 1 mV greater
than the thermocouple output. With a copper-constantan thermocouple, 1 mV
equates to approximately 25 °C measurement error.
7.6.3.2 External Signal Conditioner
External instruments with integrated signal conditioners, such as an infrared gas
analyzer (IRGA), are frequently used to make measurements and send analog
information to the CR1000. These instruments are often powered by the same
Vac-line source as the CR1000. Despite being tied to the same ground,
differences in current drain and lead resistance result in different ground
potentials at the two instruments. For this reason, a differential measurement
should be made on the analog output from the external signal conditioner.
7.6.4
Ground Looping in Ionic Measurements
When measuring soil-moisture with a resistance block, or water conductivity with
a resistance cell, the potential exists for a ground loop error. In the case of an
ionic soil matric potential (soil moisture) sensor, a ground loop arises because soil
109
Section 7. Installation
and water provide an alternate path for the excitation to return to CR1000 ground.
This example is modeled in the diagram Model of a Ground Loop with a Resistive
Sensor (p. 110). With Rg in the resistor network, the signal measured from the sensor
is described by the following equation:
where
Vx is the excitation voltage
Rf is a fixed resistor
Rs is the sensor resistance
Rg is the resistance between the excited electrode and CR1000 earth ground.
RxRf/Rg is the source of error due to the ground loop. When Rg is large, the error
is negligible. Note that the geometry of the electrodes has a great effect on the
magnitude of this error. The Delmhorst gypsum block used in the Campbell
Scientific 227 probe has two concentric cylindrical electrodes. The center
electrode is used for excitation; because it is encircled by the ground electrode, the
path for a ground loop through the soil is greatly reduced. Moisture blocks which
consist of two parallel plate electrodes are particularly susceptible to ground loop
problems. Similar considerations apply to the geometry of the electrodes in water
conductivity sensors.
The ground electrode of the conductivity or soil moisture probe and the CR1000
earth ground form a galvanic cell, with the water/soil solution acting as the
electrolyte. If current is allowed to flow, the resulting oxidation or reduction will
soon damage the electrode, just as if dc excitation was used to make the
measurement. Campbell Scientific resistive soil probes and conductivity probes
are built with series capacitors to block this dc current. In addition to preventing
sensor deterioration, the capacitors block any dc component from affecting the
measurement.
Figure 35. Model of a Ground Loop with a Resistive Sensor
110
Section 7. Installation
7.7
CR1000 Configuration — Details
Related Topics:
‡CR1000 Configuration — Overview (p. 86)
‡CR1000 Configuration — Details (p. 111)
‡Status, Settings, and Data Table Information (Status/Settings/DTI) (p. 603)
Your new CR1000 is already configured to communicate with Campbell
Scientific datalogger support software (p. 95) on the RS-232 port, and over most
telecommunication links. If you find that an older CR1000 no longer
communicates with these simple links, do a full reset of the unit, as described in
the section Resetting the CR1000 (p. 381). Some applications, especially those
implementing TCP/IP features, may require changes to factory defaults.
Configuration (verb) includes actions that modify firmware or software in the
CR1000. Most of these actions are associated with CR1000 settings registers.
For the purpose of this discussion, the CRBasic program, which, of course,
configures the CR1000, is discussed in a separate section (CRBasic Programming
— Details (p. 122)).
7.7.1
Configuration Tools
Configuration tools include the following:
x
x
x
x
x
x
x
Device Configuration Utility (p. 111)
Network Planner (p. 112)
Status/Settings/DTI (p. 114)
CRBasic program (p. 115)
Executable CPU: files (p. 115)
Keyboard display (p. 462)
Terminal emulator
7.7.1.1 Configuration with DevConfig
The most versatile configuration tool is Device Configuration Utility, or
DevConfig. It is bundled with LoggerNet, PC400, RTDAQ, or it can be
downloaded from www.campbellsci.com/downloads
(http://www.campbellsci.com/downloads). It has the following basic features:
x
x
x
x
Extensive context sensitive help
Connects directly to the CR1000 over a serial or IP connection
Facilitates access to most settings, status registers, and data table information
registers
Includes a terminal emulator that facilitates access to the command prompt of
the CR1000
DevConfig Help guides you through connection and use. The simplest connection
is to, connect a serial cable from the computer COM port or USB port to the RS232 port on the CR1000 as shown in figure Power and Serial Communication
Connections (p. 48). DevConfig updates are available at
www.campbellsci.com/downloads (http://www.campbellsci.com/downloads).
111
Section 7. Installation
Figure 36. Device Configuration Utility (DevConfig)
7.7.1.2 Network Planner
Network Planner is a drag-and-drop application used in designing PakBus
datalogger networks. You interact with Network Planner through a drawing
canvas upon which are placed PC and datalogger nodes. Links representing
various telecommunication options are drawn between nodes. Activities to take
place between the nodes are specified. Network Planner automatically specifies
settings for individual devices and creates configuring XML files to download to
each device through DevConfig (p. 111).
112
Section 7. Installation
Figure 37. Network Planner Setup
7.7.1.2.1 Overview
Network Planner allows you to
x
x
x
Create a graphical representation of a network, as shown in figure Network
Planner Setup (p. 113),
Determine settings for devices and LoggerNet, and
Program devices and LoggerNet with new settings.
Why is Network Planner needed?
x
x
x
x
PakBus protocol allows complex networks to be developed.
Setup of individual devices is difficult.
Settings are distributed across a network.
Different device types need settings coordinated.
Caveats
x
x
x
x
x
Network Planner aids in, but does not replace, the design process.
It aids development of PakBus networks only.
It does not make hardware recommendations.
It does not generate datalogger programs.
It does not understand distances or topography; that is, it does not warn when
broadcast distances are exceeded, nor does it identify obstacles to radio
transmission.
For more detailed information on Network Planner, please consult the LoggerNet
manual, which is available at www.campbellsci.com.
113
Section 7. Installation
7.7.1.2.2 Basics
PakBus Settings
x
x
x
x
x
Device addresses are automatically allocated but can be changed.
Device connections are used to determine whether neighbor lists should be
specified.
Verification intervals will depend on the activities between devices.
Beacon intervals will be assigned but will have default values.
Network role (for example, router or leaf node) will be assigned based on
device links.
Device Links and Communication Resources
x
x
x
x
x
Disallow links that will not work.
Comparative desirability of links.
Prevent over-allocation of resources.
Optimal RS-232 and CS I/O ME baud rates based on device links.
Optimal packet-size limits based on anticipated routes.
Fundamentals of Using Network Planner
x
x
x
x
x
x
Add a background (optional)
Place stations, peripherals, etc.
Establish links
Set up activities (scheduled poll, callback)
Configure devices
Configure LoggerNet (adds the planned network to the LoggerNet Network
Map)
7.7.1.3 Configuration with Status/Settings/DTI
Related Topics:
‡Status, Settings, and Data Table Information (Status/Settings/DTI) (p. 603)
‡Common Uses of the Status Table (p. 604)
‡Status Table as Debug Resource (p. 485)
The Status table, CR1000 settings, and the DataTableInfo table (collectively,
Status/Settings/DTI) contain registers, settings, and information essential to
setup, programming, and debugging of many advanced CR1000 systems.
Status/Settings/DTI are numerous. Note the following:
x
x
x
x
x
x
114
All Status/Settings/DTI, except a handful, are accessible through a keyword.
This discussion is organized around these keywords. Keywords and
descriptions are listed alphabetically in sub-appendix Status/Settings/DTI
Descriptions (Alphabetical) (p. 611).
Status fields are read only (mostly). Some are resettable.
Settings are read/write (mostly).
DTI are read only.
Directories in sub-appendix Status/Settings/DTI Directories (p. 604) list several
groupings of keywords. Each keyword listed in these groups is linked to the
relevant description.
Some Status/Settings/DTI have multiple names depending on the interface
Section 7. Installation
x
used to access them.
No single interface accesses all Status/Settings/DTI. Interfaces used for
access include the following:
Table 6. Status/Setting/DTI: Access Points
Access Point
Locate in...
Settings Editor
Device Configuration Utility, LoggerNet Connect screen,
PakBus Graph. See Datalogger Support Software — Details (p.
450).
Status
View as a data table in a numeric monitor (p. 521).
DataTableInfo
View as a data table in a numeric monitor (p. 521).
Station Status
Menu item in datalogger support software (p. 654).
Edit Settings
Menu item in PakBusGraph software.
Menu item in CR1000KD Keyboard Display Configure,
Settings
Settings
status.keyword/settings.keyword
1
Syntax in CRBasic program
Information presented in Station Status is not updated automatically. Click the Refresh button to update.
Note Communication and processor bandwidth are consumed when generating
the Status and DataTableInfo tables. If the CR1000 is very tight on processing
time, as may occur in very long or complex operations, retrieving the Status table
repeatedly may cause skipped scans (p. 487).
Status603/Settings/DTI (p. 603)can be set or accessed using CRBasic instructions
SetStatus() or SetSetting().
For example, to set the setting StationName to BlackIceCouloir, the following
syntax is used:
SetSetting("StationName","BlackIceCouloir")
where StationName is the keyword for the setting, and BlackIceCouloir is the set
value.
Settings can be requested by the CRBasic program using the following syntax:
x = Status.[setting]
where Setting is the keyword for a setting.
For example, to acquire the value set in setting StationName, use the following
statement:
x = Status.StationName
7.7.1.4 Configuration with Executable CPU: Files
Many CR1000 settings can be changed remotely over a telecommunication link
either directly, or as discussed in section Configuration with CRBasic Program (p.
115), as part of the CRBasic program. These conveniences come with the risk of
inadvertently changing settings and disabling communications. Such an
occurence will likely require an on-site visit to correct the problem if at least one
of the provisions discussed in this section is not put in place. For example,
115
Section 7. Installation
wireless-ethernet (cell) modems are often controlled by a switched 12 Vdc
(SW12) terminal. SW12 is normally off, so, if the program controlling SW12 is
disabled, such as by replacing it with a program that neglects SW12 control, the
cell modem is switched off and the remote CR1000 drops out of
telecommunications.
Executable CPU: files automatically execute according to the schedule outlined in
table . Each can contain code to set specific settings in the CR1000.
Executable CPU: files include the following:
x
x
x
'Include' file (p. 147)
Default.cr1 file (p. 116)
Powerup.ini file (p. 386)
To be used, each file needs to be created and then placed on the CPU: drive of the
CR1000. The 'include' file and default.cr1 file consist of CRBasic code.
Powerup.ini has a different, limited programming language.
7.7.1.4.1 Default.cr1 File
A file named default.cr1 can be stored on the CR1000 CPU: drive. At power up,
the CR1000 loads default.cr1 if no other program takes priority (see Executable
File Run Priorities (p. 116)). Default.cr1 can be edited to preserve critical
datalogger settings such as communication settings, but cannot be more than a
few lines of code.
Downloading operating systems over telecommunications requires much of the
available CR1000 memory. If the intent is to load operating systems via a
telecommunication link, and have a default.cr1 file in the CR1000, the default.cr1
program should not allocate significant memory, as might happen by allocating a
large USR: drive. Do not use a DataTable() instruction set for auto allocation of
memory, either. Refer to the section Updating the Operating System (OS) (p. 117)
for information about sending the operating system.
Execution of default.cr1 at power-up can be aborted by holding down the DEL
key on the CR1000KD Keyboard Display.
CRBasic Example 1.
Simple Default.cr1 File to Control SW1Ϯ Terminal
'This program example demonstrates use of a Default.cr1 file. It must be restricted
'to few lines of code. This program controls the SW12 switched power terminal, which
'may be helpful in assuring that the default power state of a remote modem is ON.
BeginProg
Scan(1,Sec,0,0)
If TimeIntoInterval(15,60,Sec) Then SW12(1)
If TimeIntoInterval(45,60,Sec) Then SW12(0)
NextScan
EndProg
7.7.1.4.2 Executable File Run Priorities
1. When the CR1000 powers up, it executes commands in the powerup.ini file (on
Campbell Scientific mass storage device or memory card including commands
to set the CRBasic program file attributes to Run Now or Run On Power-up.
2. When the CR1000 powers up, a program file marked as Run On Power-up
116
Section 7. Installation
will be the current program. Otherwise, any file marked as Run Now will be
used.
3. If there is a file specified in the Include File Name setting, it is compiled at the
end of the program selected in step.
4. If there is no file selected in step 1, or if the selected file cannot be compiled,
the CR1000 will attempt to run the program listed in the Include File Name
setting. The CR1000 allows a SlowSequence statement to take the place of
the BeginProg statement. This allows the "Include File" to act as the default
program.
5. If the program listed in the Include File Name setting cannot be run or if no
program is specified, the CR1000 will attempt to run the program named
default.cr1 on its CPU: drive.
6. If there is no default.cr1 file or it cannot be compiled, the CR1000 will not
automatically run any program.
7.7.2
CR1000 Configuration — Details
Following are a few common configuration actions:
x
x
x
x
x
Updating the operating system (p. 117).
Access a CR1000 register (p. 114) to help troubleshoot
Set the CR1000 clock
Save current configuration
Restore a configuration
Tools available to perform these actions are listed in the following table:
Table 7. Common Configuration Actions and Tools
1
Action
Tools to Use
Updating the operating system
DevConfig (p. 111) software, Program Send (p.
524), memory card (p. 89), mass storage device
Access a register
DevConfig, PakBus Graph, CRBasic program,
'Include' file (p. 147), Default.cr1 file (p. 116).
Set the CR1000 clock
DevConfig, PC200W, PC400, LoggerNet
Save / restore configuration
DevConfig
1
Tools are listed in order of preference.
7.7.2.1 Updating the Operating System (OS)
The CR1000 is shipped with the operating system pre-loaded. Check the preloaded version by connecting your PC to the CR1000 using the procedure
outlined in DevConfig Help. OS version is displayed in the following location:
Deployment tab
Datalogger tab
OS Version text box
117
Section 7. Installation
Update the OS on the CR1000 as directed in DevConfig Help. The current
version of the OS is found at www.campbellsci.com/downloads. OS updates are
free of charge.
Note An OS file has a .obj extension. It can be compressed using the gzip
compression algorithm. The datalogger will accept and decompress the file on
receipt. See the appendix Program and OS Compression (p. 463).
Note the following precautions:
x
Since sending an OS resets CR1000 memory, data loss will certainly occur.
Depending on several factors, the CR1000 may also become incapacitated for
a time.
o
o
o
x
Is sending the OS necessary to correct a critical problem? If not,
consider waiting until a scheduled maintenance visit to the site.
Is the site conveniently accessible such that a site visit can be undertaken
to correct a problem of reset settings without excessive expense?
If the OS must be sent, and the site is difficult or expensive to access, try
the OS download procedure on an identically programmed, more
conveniently located CR1000.
Campbell Scientific recommends upgrading operating systems only with a
direct-hardwire link. However, the Send Program (p. 524) button in the
datalogger support software (p. 654) allows the OS to be sent over all software
supported telecommunication systems.
o
o
Operating systems are very large files — be cautious of line charges.
Updating the OS may reset CR1000 settings, even settings critical to
supporting the telecommunication link. Newer operating systems
minimize this risk.
Note Beginning with OS 25, the OS has become large enough that a CR1000
ZLWKVHULDOQXPEHU”ZKLFKKDVRQO\0%RI65$0PD\QRWKDYH
enough memory to receive it under some circumstances. If problems are
encountered with a 2 MB CR1000, sending the OS over a direct serial connection
is usually successful.
The operating system is updated with one of the following tools:
7.7.2.1.1 OS Update with DevConfig Send OS Tab
Using this method results in the CR1000 being restored to factory defaults. The
existing OS is over written as it is received. Failure to receive the complete new
OS will leave the CR1000 in an unstable state. Use this method only with a direct
hardwire serial connection.
How
Use the following procedure with DevConfig: Do not software Connect to the
CR1000.
1. Select CR1000 from the list of devices at left
2. Select the appropriate communication port and baud rate at the bottom left
3. Click the Send OS tab located at the top of DevConfig window
118
Section 7. Installation
4. Follow the on-screen OS Download Instructions
Pros/Cons
This is a good way to recover a CR1000 that has gone into an unresponsive state.
Often, an operating system can be loaded even if you are unable to communicate
with the CR1000 through other means.
Loading an operating system through this method will do the following:
1. Restore all CR1000 settings to factory defaults
2. Delete data in final storage
3. Delete data from and remove the USR drive
4. Delete program files stored on the datalogger
7.7.2.1.2 OS Update with DevConfig
This method is very similar to sending an OS as a program, with the exception
that you have to manually prepare the datalogger to accept the new OS.
How
1. Connect to the CR1000 with Connect or DevConfig
2. Collect data
3. Transfer a default.CR1 (p. 116) program file to the CR1000 CPU: drive
4. Stop the current program and select the option to delete associated data (this
will free up SRAM memory allocated for data storage)
5. Collect files from the USR: drive (if applicable)
6. Delete the USR: drive (if applicable)
7. Send the new .obj OS file to the CR1000
8. Restart the previous program (default.CR1 will be running after OS compiles)
Pros/Cons
This method is preferred because the user must manually configure the datalogger
to receive an OS and thus should be cognizant of what is happening (loss of data,
program being stopped, etc.).
Loading an operating system through this method will do the following:
1. Preserve all CR1000 settings
2. Delete all data in final storage
3. Delete USR: drive
4. Stop current program deletes data and clears run options
5. Deletes data generated using the CardOut() or TableFile() instructions
7.7.2.1.3 OS Update with DevConfig
A send program command is a feature of DevConfig and other datalogger support
software (p. 654). Location of this command in the software is listed in table
Program Send Command Locations
119
Section 7. Installation
Program Send Command Locations
Datalogger Support
Software
Name of Button
Location of Button
DevConfig
Send Program
Logger Control tab lower left
LoggerNet
Send New...
Connect window, lower right
PC400
Send Program
Main window, lower right
PC200W
Send Program
Main window, lower right
RTDAQ
Send Program
Main window, lower right
This method results in the CR1000 retaining its settings (a feature since OS
version 16). The new OS file is temporarily stored in CR1000 SRAM memory,
which necessitates the following:
x
x
Sufficient memory needs to be available. Before attempting to send the OS,
you may need to delete other files in the CPU: and USR: drives, and you may
need to remove the USR: drive altogether. Since OS 25, older 2 MB
CR1000s do not have sufficient memory to perform this operation.
SRAM will be cleared to make room, so program run options and data will be
lost. If CR1000 communications are controlled with the current program,
first load a default.cr1 CRBasic program on to the CPU: drive. Default.cr1
will run by default after the CR1000 compiles the new OS and clears the
current run options.
How
From the LoggerNet Connect window, perform the following steps:
1. Connect to the station
2. Collect data
3. Click the Send New…
4. Select the OS file to send
5. Restart the existing program through File Control, or send a new program with
CRBasic Editor and specify new run options.
Pros/Cons
This is the best way to load a new operating system on the CR1000 and have its
settings retained (most of the time). This means that you will still be able to
communicate with the station because the PakBus address is preserved and
PakBusTCP client connections are maintained. Plus, if you are using a TCP/IP
connection, the file transfer is much faster than loading a new OS directly through
DevConfig.
The bad news is that, since it clears the run options for the current program, you
can lose communications with the station if power is toggled to a communication
peripheral under program control, such as turning a cell modem on/off to conserve
power use.
Also, if sufficient memory is not available, instability may result. It’s probably
best to clear out the memory before attempting to send the new OS file. If you
have defined a USR drive you will probably need to remove it as well.
120
Section 7. Installation
Loading an operating system through this method will do the following:
1. Preserve all CR1000 settings
2. Delete all data in final storage
3. Stop current program (Stop and deletes data) and clears run options
4. Deletes data generated using the CardOut() instruction
7.7.2.1.4 OS Update with DevConfig
How
1. Place a powerup.ini (p. 386) text file and operating system .obj file on the external
memory device
2. Attached the external memory device to the datalogger
3. Power cycle the datalogger
Pros/Cons
This is a great way to change the OS without a laptop in the field. The down side
is only if you want to do more than one thing with the powerup.ini, such as
change OS and load a new program, which necessitates that you use separate
cards or modify the .ini file between the two tasks you wish to perform.
Loading an operating system through this method will do the following:
1. Preserve all datalogger settings
2. Delete all data in final storage
3. Preserve USR drive and data stored there
4. Maintains program run options
5. Deletes data generated using the CardOut() or TableFile() instructions
DevConfig Send OS tab:
x
x
If you are having trouble communicating with the CR1000
If you want to return the CR1000 to a known configuration
Send Program (p. 524) or Send New... command:
x
x
If you want to send an OS remotely
If you are not too concerned about the consequences
File Control tab:
x
x
x
If you want to update the OS remotely
If your only connection to the CR1000 is over IP
If you have IP access and want to change the OS for testing purposes
External memory and PowerUp.ini file:
x
If you want to change the OS without a PC
121
Section 7. Installation
7.7.2.2 Restoring Factory Defaults
In DevConfig, clicking the Factory Defaults button at the base of the Settings
Editor tab sends a command to the CR1000 to revert to its factory default
settings. The reverted values will not take effect until the changes have been
applied.
7.7.2.3 Saving and Restoring Configurations
In DevConfig, clicking Save on a summary screen saves the configuration to an
XML file. This file can be used to load a saved configuration back into the
CR1000 by clicking Read File and Apply.
Figure 38. Summary of CR1000 Configuration
7.8
CRBasic Programming — Details
Related Topics:
‡CRBasic Programming — Overview (p. 86)
‡CRBasic Programming — Details (p. 122)
‡CRBasic Programming — Instructions (p. 537)
‡Programming Resource Library (p. 169)
‡CRBasic Editor Help
Programs are created with either Short Cut (p. 528) or CRBasic Editor (p. 125). Old
CR10X and CR23X programs can be converted to CRBasic code using
Transformer.exe (executable file included with LoggerNet). Programs can be up
to 490 KB in size; most programs, however, are much smaller.
122
Section 7. Installation
7.8.1
Program Structure
Essential elements of a CRBasic program are listed in the table CRBasic Program
Structure (p. 123) and demonstrated in CRBasic example Program Structure (p. 123).
Table 8. CRBasic Program Structure
Declarations
Define CR1000 memory usage. Declare constants,
variables, aliases, units, and data tables.
Declare constants
List fixed constants.
Declare Public variables
List / dimension variables viewable during program
execution.
Declare Dim variables
List / dimension variables not viewable during
program execution.
Define Aliases
Assign aliases to variables.
Define Units
Assign engineering units to variable (optional).
Units are strictly for documentation. The CR1000
makes no use of Units nor checks Unit accuracy.
Define data tables.
Define stored data tables.
Process / store trigger
Set triggers when data should be stored. Triggers
may be a fixed interval, a condition, or both.
Table size
Set the size of a data table.
Other on-line storage devices
Send data to a Campbell Scientific mass storage
device or memory card if available.
List data to be stored in the data table, e.g. samples,
averages, maxima, minima, etc.
Processing of data
Processes or calculations repeated during program
execution can be packaged in a subroutine and
called when needed rather than repeating the code
each time.
Begin program
Begin program defines the beginning of statements
defining CR1000 actions.
Set scan interval
The scan sets the interval for a series of
measurements.
Measurements
Enter measurements to make.
Processing
Enter any additional processing.
Call data table(s)
Declared data tables must be called to process and
store data.
Initiate controls
Check measurements and initiate controls if
necessary.
NextScan
Loop back to set scan and wait for the next scan.
End program
End program defines the ending of statements
defining CR1000 actions.
123
Section 7. Installation
CRBasic Program Structure
'Declarations
'Define Constants
Const RevDiff = 1
Const Del = 0 'default
Const Integ = 250
Const Mult = 1
Const Offset = 0
Declare constants
'Define public variables
Public RefTemp
Public TC(6)
'Define Units
Units RefTemp = degC
Units TC = DegC
'Define data tables
DataTable(Temp,1,2000)
DataInterval(0,10,min,10)
Average(1,RefTemp,FP2,0)
Average(6,TC(),FP2,0)
EndTable
Declare public variables,
dimension array, and declare
units.
Declarations
Define data table
'Begin Program
BeginProg
'Set scan interval
Scan(1,Sec,3,0)
'Measurements
PanelTemp(RefTemp,250)
TCDiff(TC()...Offset)
Measure
'Processing (None in this
'example)
Scan loop
'Call data table
CallTable Temp
'Controls (None in this
'example)
'Loop to next scan
NextScan
'End Program
EndProg
124
Call data table
Section 7. Installation
7.8.2
Writing and Editing Programs
7.8.2.1 Short Cut Programming Wizard
Short Cut is easy-to-use, menu-driven software that presents lists of predefined
measurement, processing, and control algorithms from which to choose. You
make choices, and Short Cut writes the CRBasic code required to perform the
tasks. Short Cut creates a wiring diagram to simplify connection of sensors and
external devices. Quickstart Tutorial (p. 41) works through a measurement example
using Short Cut.
For many complex applications, Short Cut is still a good place to start. When as
much information as possible is entered, Short Cut will create a program template
from which to work, already formatted with most of the proper structure,
measurement routines, and variables. The program can then be edited further
using CRBasic Program Editor.
7.8.2.2 CRBasic Editor
CR1000 application programs are written in a variation of BASIC (Beginner's
All-purpose Symbolic Instruction Code) computer language, CRBasic (Campbell
Recorder BASIC). CRBasic Editor is a text editor that facilitates creation and
modification of the ASCII text file that constitutes the CR1000 application
program. CRBasic Editor is a component of LoggerNet (p. 655), RTDAQ, and
PC400 datalogger support software (p. 95).
Fundamental elements of CRBasic include the following:
x
x
Variables — named packets of CR1000 memory into which are stored values
that normally vary during program execution. Values are typically the result
of measurements and processing. Variables are given an alphanumeric name
and can be dimensioned into arrays of related data.
Constants — discrete packets of CR1000 memory into which are stored
specific values that do not vary during program executions. Constants are
given alphanumeric names and assigned values at the beginning declarations
of a CRBasic program.
Note Keywords and predefined constants are reserved for internal CR1000 use. If
a user-programmed variable happens to be a keyword or predefined constant, a
runtime or compile error will occur. To correct the error, simply change the
variable name by adding or deleting one or more letters, numbers, or the
underscore (_) from the variable name, then recompile and resend the program.
CRBasic Editor Help provides a list of keywords and predefined constants.
x
x
Common instructions — instructions (called "commands" in BASIC) and
operators used in most BASIC languages, including program control
statements, and logic and mathematical operators.
Special instructions — instructions (commands) unique to CRBasic,
including measurement instructions, and processing instructions that
compress many common calculations used in CR1000 dataloggers.
These four elements must be properly placed within the program structure.
125
Section 7. Installation
7.8.2.2.1 Inserting Comments into Program
Comments are non-executable text placed within the body of a program to
document or clarify program algorithms.
As shown in CRBasic example Inserting Comments (p. 126), comments are inserted
into a program by preceding the comment with a single quote ('). Comments can
be entered either as independent lines or following CR1000 code. When the
CR1000 compiler sees a single quote ('), it ignores the rest of the line.
CRBasic Example Ϯ.
Inserting Comments
'This program example demonstrates the insertion of comments into a program. Comments are
'placed in two places: to occupy single lines, such as this explanation does, or to be
'placed after a statement.
'Declaration of variables starts here.
Public Start(6)
'Declare the start time array
BeginProg
EndProg
7.8.2.2.2 Conserving Program Memory
One or more of the following memory-saving techniques can be used on the rare
occasions when a program reaches memory limits:
x
x
x
x
x
Declare variables as DIM instead of Public. DIM variables do not require
buffer memory for data retrieval.
Reduce arrays to the minimum size needed. Arrays save memory over the
use of scalars as there is less "meta-data" required per value. However, as a
rough approximation, 192000 (4 kB memory) or 87000 (2 kB memory)
variables will fill available memory.
Use variable arrays with aliases instead of individual variables with unique
names. Aliases consume less memory than unique variable names.
Confine string concatenation to DIM variables.
Dimension string variables only to the size required.
Read More More information on string variable-memory use and conservation is
available in String Operations (p. 282).
7.8.3
Sending CRBasic Programs
The CR1000 requires that a CRBasic program file be sent to its memory to direct
measurement, processing, and data-storage operations. The program file can have
the extension cr1 or .dld and can be compressed using the GZip algorithm before
sending it to the CR1000. Upon receipt of the file, the CR1000 automatically
decompresses the file and uses it just as any other program file. See the appendix
Program and OS Compression (p. 463) for more information.
Options for sending a program include the following:
x
x
x
126
Program Send (p. 524) command in datalogger-support software (p. 95)
Program send command in Device Configuration Utility (DevConfig (p. 111))
Campbell Scientific mass storage device (p. 653) or memory card
Section 7. Installation
A good practice is to always retrieve data from the CR1000 before sending a
program; otherwise, data may be lost.
Read More See File Management (p. 382) and the Campbell Scientific mass
storage device or memory card documentation available at www.campbellsci.com.
7.8.3.1 Preserving Data at Program Send
When sending programs to the CR1000 through the software options listed in
table Program Send Options that Reset Memory (p. 127), memory is reset and data
are erased.
When data retention is desired, send programs using the File Control Send (p. 515)
command or CRBasic Editor command Compile, Save, Send in the Compile
menu. The window shown in the figure CRBasic Editor Program Send File
Control Window (p. 127) is displayed before the program is sent. Select Run Now,
Run On Power-up, and Preserve data if no table changed before pressing Send
Program.
Note To retain data, Preserve data if no table changed must be selected
whether or not a Campbell Scientific mass storage device or memory card is
connected.
Regardless of the program-upload tool used, if any change occurs to data table
structures listed in table Data Table Structures (p. 128), data will be erased when a
new program is sent.
Table 9. Program Send Options that Reset
Memory*
LoggerNet | Connect | Program Send
PC400 | Clock/Program | Send Program
PC200W | Clock/Program | Send Program
RTDAQ | Clock/Program | Send Program
DevConfig | Logger Control | Send Program
*Reset memory and set program attributes to Run Always
Figure 39. CRBasic Editor Program Send File Control window
127
Section 7. Installation
Table 10. Data Table
Structures
–Data table name(s)
–Data-output interval or offset
–Number of fields per record
–Number of bytes per field
–Field type, size, name, or position
–Number of records in table
7.8.4
Programming Syntax
7.8.4.1 Program Statements
CRBasic programs are made up of a series of statements. Each statement
normally occupies one line of text in the program file. Statements consist of
instructions, variables, constants, expressions, or a combination of these.
"Instructions" are CRBasic commands. Normally, only one instruction is
included in a statement. However, some instructions, such as If and Then, are
allowed to be included in the same statement.
Lists of instructions and expression operators can be found in the appendix
CRBasic Programming Instructions (p. 537). A full treatment of each instruction
and operator is located in the Help files of CRBasic Editor (p. 125).
7.8.4.1.1 Multiple Statements on One Line
Multiple short statements can be placed on a single text line if they are separated
by a colon (:). This is a convenient feature in some programs. However, in
general, programs that confine text lines to single statements are easier for
humans to read.
In most cases, regarding statements separated by : as being separate lines is safe.
However, in the case of an implied EndIf, CRBasic behaves in what may be an
unexpected manner. In the case of an If...Then...Else...EndIf statement, where
the EndIf is only implied, it is implied after the last statement on the line. For
example:
If A then B : C : D
does not mean:
If A then B (implied EndIf) : C : D
Rather, it does mean:
If A then B : C : D (implied EndIf)
7.8.4.1.2 One Statement on Multiple Lines
Long statements that overrun the CRBasic Editor page width can be continued on
the next line if the statement break includes a space and an underscore ( _). The
underscore must be the last character in a text line, other than additional white
space.
128
Section 7. Installation
Note CRBasic statements are limited to 512 characters, whether or not a line
continuation is used.
Examples:
Public A, B, _
C,D, E, F
If (A And B) _
Or (C And D) _
Or (E And F) then ExitScan
7.8.4.2 Single-Statement Declarations
Single-statements are used to declare variables, constants, variable and constant
related elements, and the station name. The following instructions are used
usually before the BeginProg instruction:
x
x
x
x
x
x
Public
Dim
Constant
Units
Alias
StationName
The table Rules for Names (p. 159) lists declaration names and allowed lengths. See
the section Predefined Constants (p. 138) for other naming limitations.
7.8.4.3 Declaring Variables
A variable is a packet of memory that is given an alphanumeric name.
Measurements and processing results pass through variables during program
execution. Variables are declared as Public or Dim. Public variables are
viewable through numeric monitors (p. 521). Dim variables cannot be viewed. A
public variables can be set as read-only, using the ReadOnly instruction, so that it
cannot be changed from a numeric monitor. The program, however, continues to
have read/write access to the variable.
Declared variables are initialized once when the program starts. Additionally,
variables that are used in the Function() or Sub() declaration, or that are declared
within the body of the function or subroutine, are local to that function or
subroutine.
Variable names can be up to 39 characters in length, but most variables should be
no more than 35 characters long. This allows for four additional characters that
are added as a suffix to the variable name when it is output to a data table.
Variable names can contain the following characters:
x
x
x
x
x
A to Z
a to z
0 to 9
_ (underscore)
$
Names must start with a letter, underscore, or dollar sign. Spaces and quote
marks are not allowed. Variable names are not case sensitive.
129
Section 7. Installation
Several variables can be declared on a single line, separated by commas:
Public RefTemp, AirTemp2, Batt_Volt
Variables can also be assigned initial values in the declaration. Following is an
example of declaring a variable and assigning it an initial value.
Public SetTemp = {35}
In string variables, string size defaults to 24 characters (changed from 16
characters in April 2013, OS 26).
7.8.4.3.1 Declaring Data Types
Variables and data values stored in final memory can be configured with various
data types to optimize program execution and memory usage.
The declaration of variables with the Dim or Public instructions allows an
optional type descriptor As that specifies the data type. The default data type
(declaration without a descriptor) is IEEE4 floating point, which is equivalent to
the As Float declaration. Variable data types are listed in the table Data Types in
Variable Memory (p. 131, p. 130). Final-data memory data types are listed in the table
Data Types in Final-Data Memory (p. 131). CRBasic example Data Type
Declarations (p. 132) shows various data types in use in the declarations and output
sections of a program.
CRBasic allows mixing data types within a single array of variables; however,
this practice can result in at least one problem. The datalogger support software is
incapable of efficiently handling different data types for the same field name.
Consequently, the software mangles the field names in data file headers.
Table 11. Data Types in Variable Memory
Name
Command
Description
Word Size
(Bytes)
Float
As Float or
As IEEE4
IEEE floating point
4
Notes
Data type of all variables unless
declared otherwise.
Resolution / Range
r1.4E–45 to r3.4E38
IEEE Standard 754
Use to store count data in the range of
r2,147,483,648
Speed: integer math is faster than
floating point math.
Long
As Long
Signed integer
4
Resolution: 32 bits. Compare to 24
bits in IEEE4.
–2,147,483,648 to +2,147,483,647
Suitable for storing whole numbers,
counting number, and integers in
final-data memory. If storing nonintegers, the fractional portion of the
value is lost.
Boolean
130
As Boolean
Signed integer
4
Use to store true or false states, such
as states of flags and control ports. 0
is always false. –1 is always true.
Depending on the application, any
other number may be interpreted as
true or false. See the section True = 1, False = 0 (p. 164).
True = –RUDQ\QXPEHU•
)DOVH DQ\QXPEHU•DQG
Section 7. Installation
Table 11. Data Types in Variable Memory
Name
Command
Description
Word Size
(Bytes)
Notes
Resolution / Range
1
See caution.
Minimum: 3
(4 with null
terminator)
Default: 24
String
As String
ASCII string
Maximum:
limited only
to the size of
available
CR1000
memory.
String size is defined by the CR1000
operating system and CRBasic
program.
When converting from STRING to
FLOAT, numerics at the beginning
of a string convert, but conversion
stops when a non-numeric is
encountered. If the string begins with
a non-numeric, the FLOAT will be
NAN. If the string contains multiple
numeric values separated by nonnumeric characters, the SplitStr()
instruction can be used to parse out
the numeric values. See the sections
String Operations (p. 282) and Serial
I/O (p. 245).
Unless declared otherwise, string size is 24
bytes or characters. String size is allocated
in multiples of four bytes; for example,
String * 25, String * 26, String * 27, and
String * 28 allocate 28 bytes (27 usable).
Minimum string size is 4 (3 usable). See
CRBasic Editor Help for more information.
Maximum length is limited only by
available CR1000 memory.
1
CAUTION When using a very long string in a variable declared Public, the operations of datalogger support software (p. 654) will frequently transmit
the entire string over the communication link. If communication bandwidth is limited, or if communications are paid for by they byte, declaring the
variable Dim may be preferred.
Table 12. Data Types in Final-Data Memory
Name
FP2
IEEE4
Argument
FP2
IEEE4 or
Float
Description
Campbell Scientific
floating point
IEEE floating point
Word Size
(Bytes)
2
4
Notes
Default final-memory data type. Use
FP2 for stored data requiring 3 or 4
significant digits. If more significant
digits are needed, use IEEE4 or an
offset.
IEEE Standard 754
Resolution / Range
Zero
Minimum
Maximum
0.000
±0.001
±7999.
Absolute
Value
Decimal Location
0 – 7.999
X.XXX
8 – 79.99
XX.XX
80 – 799.9
XXX.X
800 – 7999.
XXXX.
r1.4E–45 to r3.4E38
Use to store count data in the range of
r2,147,483,648
Speed: integer math is faster than
floating point math.
Long
Long
Signed integer
4
Resolution: 32 bits. Compare to 24
bits in IEEE4.
–2,147,483,648 to +2,147,483,647
Suitable for storing whole numbers,
counting number, and integers in
final-data memory. If storing nonintegers, the fractional portion of the
value is lost.
131
Section 7. Installation
Table 12. Data Types in Final-Data Memory
Name
Argument
Description
Word Size
(Bytes)
Notes
Resolution / Range
8VHWRVWRUHSRVLWLYHFRXQWGDWD”
+65535.
UINT2
UINT2
Unsigned integer
2
Use to store port or flag status. See
CRBasic example Load binary
information into a variable (p. 139).
When Public FLOATs convert to
UINT2 at final data storage, values
outside the range 0 – 65535 yield
unusable data. INF converts to
65535. NAN converts to 0.
0 to 65535
8VHWRVWRUHSRVLWLYHFRXQWGDWD”
2147483647.
UINT4
UINT4
Unsigned integer
4
Other uses include storage of long ID
numbers (such as are read from a bar
reader), serial numbers, or address.
0 to 2147483647
May also be required for use in some
Modbus devices.
Boolean
Bool8
NSEC
Boolean
Bool8
NSEC
Signed integer
Integer
Time stamp
4
Use to store true or false states, such
as states of flags and control ports. 0
is always false. –1 is always true.
Depending on the application, any
other number may be interpreted as
true or false. See the section True = 1, False = 0 (p. 164). To save
memory, consider using UINT2 or
BOOL8.
True = –RUDQ\QXPEHU•
)DOVH DQ\QXPEHU•DQG
1
8 bits (0 or 1) of information. Uses
less space than 32-bit BOOLEAN.
Holding the same information in
BOOLEAN will require 256 bits.
See Bool8 Data Type (p. 198).
True = 1, False = 0
8
Divided up as four bytes of seconds
since 1990 and four bytes of
nanoseconds into the second. Used to
record and process time data. See
NSEC Data Type (p. 202).
1 nanosecond
1
See caution.
Minimum: 3
(4 with null
terminator)
Default: 24
String
132
String
ASCII string
Maximum:
limited only
to the size of
available
CR1000
memory.
String size is defined by the CR1000
operating system and CRBasic
program.
When converting from STRING to
FLOAT, numerics at the beginning
of a string convert, but conversion
stops when a non-numeric is
encountered. If the string begins with
a non-numeric, the FLOAT will be
NAN. If the string contains multiple
numeric values separated by nonnumeric characters, the SplitStr()
instruction can be used to parse out
the numeric values. See the sections
String Operations (p. 282) and Serial
I/O (p. 245)..
Unless declared otherwise, string size is 24
bytes or characters. String size is allocated
in multiples of four bytes; for example,
String * 25, String * 26, String * 27, and
String * 28 allocate 28 bytes (27 usable).
Minimum string size is 4 (3 usable). See
CRBasic Editor Help for more information.
Maximum length is limited only by
available CR1000 memory.
Section 7. Installation
CRBasic Example 3.
Data Type Declarations
'This program example demonstrates various data type declarations.
'Data type declarations associated with any one variable occur twice: first in a Public
'or Dim statement, then in a DataTable/EndTable segment. If not otherwise specified, data
'types default to floating point: As Float in Public or Dim declarations, FP2 in data
'table declarations.
'Float Variable Examples
Public Z
Public X As Float
'Long Variable Example
Public CR1000Time As Long
Public PosCounter As Long
Public PosNegCounter As Long
'Boolean Variable Examples
Public Switches(8) As Boolean
Public FLAGS(16) As Boolean
'String Variable Example
Public FirstName As String * 16 'allows a string up to 16 characters long
DataTable(TableName,True,-1)
'FP2 Data Storage Example
Sample(1,Z,FP2)
'IEEE4 / Float Data Storage Example
Sample(1,X,IEEE4)
'UINT2 Data Storage Example
Sample(1,PosCounter,UINT2)
'LONG Data Storage Example
Sample(1,PosNegCounter,Long)
'STRING Data Storage Example
Sample(1,FirstName,String)
'BOOLEAN Data Storage Example
Sample(8,Switches(),Boolean)
'BOOL8 Data Storage Example
Sample(2,FLAGS(),Bool8)
'NSEC Data Storage Example
Sample(1,CR1000Time,Nsec)
EndTable
BeginProg
'Program logic goes here
EndProg
133
Section 7. Installation
7.8.4.3.2 Dimensioning Numeric Variables
Some applications require multi-dimension arrays. Array dimensions are
analogous to spatial dimensions (distance, area, and volume). A single-dimension
array, declared as,
Public VariableName(x)
with (x) being the index, denotes x number of variables as a series.
A two-dimensional array, declared as,
Public VariableName(x,y)
with (x,y) being the indices, denotes (x ‡y) number of variables in a square x-by-y
matrix.
Three-dimensional arrays, declared as
Public VariableName (x,y,z)
ZLWK[\]EHLQJWKHLQGLFHVKDYH[‡\‡]QXPEHURIYDULDEOHVLQDFXELF[-byy-by-z matrix. Dimensions greater than three are not permitted by CRBasic.
When using variables in place of integers as dimension indices (see CRBasic
example Using variable array dimension indices (p. 134)), declaring the indices As
Long variables is recommended. Doing so allows for more efficient use of
CR1000 resources.
CRBasic Example 4.
Using Variable Array Dimension Indices
'This program example demonstrates the use of dimension indices in arrays. The variable
'VariableName is declared with three dimensions with 4 in each index. This indicates the
'array has means it has 64 elements. Element 24 is loaded with the value 2.718.
'
Dim aaa As Long
Dim bbb As Long
Dim ccc As Long
Public VariableName(4,4,4) As Float
BeginProg
Scan(1,sec,0,0)
aaa = 3
bbb = 2
ccc = 4
VariableName(aaa,bbb,ccc) = 2.718
NextScan
EndProg
7.8.4.3.3 Dimensioning String Variables
Strings can be declared to a maximum of two dimensions. The third "dimension"
is used for accessing characters within a string. See String Operations (p. 282).
String length can also be declared. See the table Data Types in Variable Memory.
(p. 131, p. 130)
A one-dimension string array called StringVar, with five elements in the array
and each element with a length of 36 characters, is declared as
Public StringVar(5) As String * 36
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Section 7. Installation
Five variables are declared, each 36 characters long:
StringVar(1)
StringVar(2)
StringVar(3)
StringVar(4)
StringVar(5)
7.8.4.3.4 Declaring Flag Variables
A flag is a variable, usually declared As Boolean (p. 508), that indicates True or
False, on or off, go or not go, etc. Program execution can be branched based on
the value in a flag. Sometime flags are simply used to inform an observer that an
event is occurring or has occurred. While any variable of any data type can be
used as a flag, using Boolean variables, especially variables named "Flag", usually
works best in practice. CRBasic example Flag Declaration and Use (p. 135)
demonstrates changing words in a string based on a flag.
CRBasic Example ϱ.
Flag Declaration and Use
'This program example demonstrates the declaration and use of flags as Boolean variables,
'and the use of strings to report flag status. To run the demonstration, send this program
'to the CR1000, then toggle variables Flag(1) and Flag(2) to true or false to see how the
'program logic sets the words "High" or "Low" in variables FlagReport(1) and FlagReport(2).
'To set a flag to true when using LoggerNet Connect Numeric Monitor, simply click on the
'forest green dot adjacent to the word "false." If using a keyboard, a choice of "True" or
'"False" is made available.
Public Flag(2) As Boolean
Public FlagReport(2) As String
BeginProg
Scan(1,Sec,0,0)
If Flag(1) = True Then
FlagReport(1) = "High"
Else
FlagReport(1) = "Low"
EndIf
If Flag(2) = True Then
FlagReport(2) = "High"
Else
FlagReport(2) = "Low"
EndIf
NextScan
EndProg
7.8.4.4 Declaring Arrays
Related Topics:
‡Declaring Arrays (p. 135)
‡$UUD\VRI0XOWLSOLHUVDQG2IIVHWV
‡VarOutOfBounds (p. 488)
Multiple variables of the same root name can be declared. The resulting series of
like-named variables is called an array. An array is created by placing a suffix of
135
Section 7. Installation
(x) on the variable name. X number of variables are created that differ in name
only by the incrementing number in the suffix. For example, the four statements
Public
Public
Public
Public
TempC1
TempC2
TempC3
TempC4
can simply be condensed to
Public TempC(4).
This statement creates in memory the four variables TempC(1), TempC(2),
TempC(3), and TempC(4).
A variable array is useful in program operations that affect many variables in the
same way. CRBasic example Using a Variable Array in Calculations (p. 136)
shows compact code that converts four temperatures (°C) to °F.
In this example, a For/Next structure with an incrementing variable is used to
specify which elements of the array will have the logical operation applied to
them. The CRBasic For/Next function will only operate on array elements that
are clearly specified and ignore the rest. If an array element is not specifically
referenced, as is the case in the declaration
Dim TempC()
CRBasic references only the first element of the array, TempC(1).
See CRBasic example Concatenation of Numbers and Strings (p. 284) for an
example of using the += assignment operator (p. 565) when working with arrays.
CRBasic Example 6.
Using a Variable Array in Calculations
'This program example demonstrates the use of a variable array to reduce code. In this
'example, two variable arrays are used to convert four temperature measurements from
'degree C to degrees F.
Public TempC(4)
Public TempF(4)
Dim T
BeginProg
Scan(1,Sec,0,0)
Therm107(TempC(),1,1,Vx1,0,250,1.0,0)
Therm107(TempC(),1,2,Vx1,0,250,1.0,0)
Therm107(TempC(),1,3,Vx1,0,250,1.0,0)
Therm107(TempC(),1,4,Vx1,0,250,1.0,0)
For T = 1 To 4
TempF(T) = TempC(T) * 1.8 + 32
Next T
NextScan
EndProg
7.8.4.5 Declaring Local and Global Variables
Advanced programs may use subroutines (p. 288) or functions (p. 602), each of which
can have a set of Dim variables dedicated to that subroutine or function. These
136
Section 7. Installation
are called local variables. Names of local variable can be identical to names of
global variables (p. 517) and to names of local variables declared in other
subroutines and functions. This feature allows creation of a CRBasic library of
reusable subroutines and functions that will not cause variable name conflicts. If
a program with local Dim variables attempts to use them globally, the compile
error undeclared variable will occur.
To make a local variable displayable, in cases where making it public creates a
naming conflict, sample the local variable to a data table and display the data
element table in a numeric monitor (p. 521).
When exchanging the contents of a global and local variables, declare each
passing / receiving pair with identical data types and string lengths.
7.8.4.6 Initializing Variables
By default, variables are set equal to zero at the time the datalogger program
compiles. Variables can be initialized to non-zero values in the declaration.
Examples of syntax are shown in CRBasic example Initializing Variables (p. 137).
CRBasic Example 7.
Initializing Variables
'This program example demonstrates how variables can be declared as specific data types.
'Variables not declared as a specific data type default to data type Float. Also
'demonstrated is the loading of values into variables that are being declared.
Public aaa As Long = 1 'Declaring a single variable As Long and loading the value of 1.
Public bbb(2) As String *20 = {"String_1", "String_2"} 'Declaring an array As String and
'loading strings in each element.
Public ccc As Boolean = True 'Declaring a variable As Boolean and loading the value of True.
'Initialize variable ddd elements 1,1 1,2 1,3 & 2,1.
'Elements (2,2) and (2,3) default to zero.
Dim ddd(2,3)= {1.1, 1.2, 1.3, 2.1}
'Initialize variable eee
Dim eee = 1.5
BeginProg
EndProg
7.8.4.7 Declaring Constants
CRBasic example Using the Const Declaration (p. 137) shows use of the constant
declaration. A constant can be declared at the beginning of a program to assign an
alphanumeric name to be used in place of a value so the program can refer to the
name rather than the value itself. Using a constant in place of a value can make
the program easier to read and modify, and more secure against unintended
changes. If declared using ConstTable / EndConstTable, constants can be
changed while the program is running by using the CR1000KD Keyboard Display
menu (Configure, Settings | Constant Table) or the C command in a terminal
emulator (see Troubleshooting – Terminal Emulator (p. 501) ).
Note Using all uppercase for constant names may make them easier to recognize.
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Section 7. Installation
CRBasic Example 8.
Using the Const Declaration
'This program example demonstrates the use of the Const declaration.
'Declare variables
Public PTempC
Public PTempF
'Declare constants
Const CtoF_Mult = 1.8
Const CtoF_Offset = 32
BeginProg
Scan(1,Sec,0,0)
PanelTemp(PTempC,250)
PTempF = PTempC * CtoF_Mult + CtoF_Offset
NextScan
EndProg
7.8.4.7.1 Predefined Constants
Many words are reserved for use by CRBasic. These words cannot be used as
variable or table names in a program. Predefined constants include instruction
names and valid alphanumeric names for instruction parameters. On account the
list of predefined constants is long and frequently increases as the operating
system is developed, the best course is to compile programs frequently during
CRBasic program development. The compiler will catch the use of any reserved
words. Following are listed predefined constants that are assigned a value:
x
LoggerType = 1000 (as in CR1000)
These may be useful in programming.
7.8.4.8 Declaring Aliases and Units
A variable can be assigned a second name, or alias, in the CRBasic program.
Aliasing is particularly useful when using arrays. Arrays are powerful tools for
complex programming, but they place near identical names on multiple variables.
Aliasing allows the power of the array to be used with the clarity of unique
names.
The declared variable name can be used interchangeably with the declared alias in
the body of the CRBasic program. However, when a value is stored to finalmemory, the value will have the alias name attached to it. So, if the CRBasic
program needs to access that value, the program must use the the alias-derived
name.
Variables in one, two, and three dimensional arrays can be assigned units. Units
are not used elsewhere in programming, but add meaning to resultant data table
headers. If different units are to be used with each element of an array, first
assign aliases to the array elements and then assign units to each alias. For
example:
Alias var_array(1) = solar_radiation
Alias var_array(2) = quanta
Units solar_radiation = Wm-2
Units variable2 = moles_m-2_s-1
138
Section 7. Installation
7.8.4.9 Numerical Formats
Four numerical formats are supported by CRBasic. Most common is the use of
base-10 numbers. Scientific notation, binary, and hexadecimal formats can also
be used, as shown in the table Formats for Entering Numbers in CRBasic (p. 139).
Only standard, base-10 notation is supported by Campbell Scientific hardware and
software displays.
Table 13. Formats for Entering Numbers in CRBasic
Format
Example
Base-10 Equivalent Value
Standard
6.832
6.832
Scientific notation
5.67E-8
Binary
&B1101
13
Hexadecimal
&HFF
255
5.67X10
-8
Binary format (1 = high, 0 = low) is useful when loading the status of multiple
flags or ports into a single variable. For example, storing the binary number
&B11100000 preserves the status of flags 8 through 1: flags 1 to 5 are low, 6 to 8
are high. CRBasic example Load binary information into a variable (p. 139) shows
an algorithm that loads binary status of flags into a LONG integer variable.
CRBasic Example 9.
Load binary information into a variable
'This program example demonstrates how binary data are loaded into a variable. The binary
'format (1 = high, 0 = low) is useful when loading the status of multiple flags
'or ports into a single variable. For example, storing the binary number &B11100000
'preserves the status of flags 8 through 1: flags 1 to 5 are low, 6 to 8 are high.
'This example demonstrates an algorithm that loads binary status of flags into a LONG
'integer variable.
Public FlagInt As Long
Public Flag(8) As Boolean
Public I
DataTable(FlagOut,True,-1)
Sample(1,FlagInt,UINT2)
EndTable
BeginProg
Scan(1,Sec,3,0)
FlagInt = 0
For I = 1 To 8
If Flag(I) = true Then
FlagInt = FlagInt + 2 ^ (I - 1)
EndIf
Next I
CallTable FlagOut
NextScan
EndProg
139
Section 7. Installation
7.8.4.10 Multi-Statement Declarations
Multi-statement declarations are used to declare data tables, subroutines,
functions, and incidentals. Related instructions include the following:
x
x
x
x
x
x
x
DataTable() / EndTable
Sub() / EndSub
Function() / EndFunction
ShutDown / ShutdownEnd
DialSequence() / EndDialSequence
ModemHangup() / EndModemHangup
WebPageBegin() / WebPageEnd
Multi-statement declarations can be located as follows:
x
x
x
7.8.4.10.1
Prior to BeginProg,
After EndSequence or an infinite Scan() / NextScan and before EndProg or
SlowSequence
Immediately following SlowSequence. SlowSequence code starts executing
after any declaration sequence. Only declaration sequences can occur after
EndSequence and before SlowSequence or EndProg.
Declaring Data Tables
Data are stored in tables as directed by the CRBasic program. A data table is
created by a series of CRBasic instructions entered after variable declarations but
before the BeginProg instruction. These instructions include:
DataTable()
'Output Trigger Condition(s)
'Output Processing Instructions
EndTable
A data table is essentially a file that resides in CR1000 memory. The file is
written to each time data are directed to that file. The trigger that initiates data
storage is tripped either by the CR1000 clock, or by an event, such as a high
temperature. The number of data tables declared is limited only by the available
CR1000 memory (prior to OS 28, the limit was 30 data tables). Data tables may
store individual measurements, individual calculated values, or summary data
such as averages, maxima, or minima to data tables.
Each data table is associated with overhead information that becomes part of the
ASCII file header (first few lines of the file) when data are downloaded to a PC.
Overhead information includes the following:
x
x
x
x
x
Table format
Datalogger type and operating system version
Name of the CRBasic program running in the datalogger
Name of the data table (limited to 20 characters)
Alphanumeric field names to attach at the head of data columns
This information is referred to as "table definitions."
140
Section 7. Installation
Table 14. Typical Data Table
TOA5
CR1000
CR1000
1048
CR1000.Std.13.06
CPU:Data.cr1
TIMESTAMP
RECORD
BattVolt_Avg
PTempC_Avg
TempC_Avg(1)
TempC_Avg(2)
TS
RN
Volts
Deg C
Deg C
Deg C
Avg
Avg
Avg
Avg
7/11/2007 16:10
0
13.18
23.5
23.54
25.12
7/11/2007 16:20
1
13.18
23.5
23.54
25.51
7/11/2007 16:30
2
13.19
23.51
23.05
25.73
7/11/2007 16:40
3
13.19
23.54
23.61
25.95
7/11/2007 16:50
4
13.19
23.55
23.09
26.05
7/11/2007 17:00
5
13.19
23.55
23.05
26.05
7/11/2007 17:10
6
13.18
23.55
23.06
25.04
35723
OneMin
The table Typical Data Table (p. 140) shows a data file as it appears after the
associated data table is downloaded from a CR1000 programmed with the code in
CRBasic example Definition and Use of a Data Table (p. 142). The data file
consists of five or more lines. Each line consists of one or more fields. The first
four lines constitute the file header. Subsequent lines contain data.
Note Discrete data files (ASCII or binary) can also be written to a CR1000
memory drive using the TableFile() instruction.
The first header line is the environment line. It consists of eight fields, listed in
table TOA5 Environment Line (p. 141).
Table 15. TOA5 Environment Line
Field
Description
1
TOA5
2
Station name
Changed By
DevConfig or CRBasic program acting on
the setting
3
Datalogger model
4
Datalogger serial number
5
Datalogger OS version
New OS
6
Datalogger program name
New program
7
Datalogger program signature
New or revised program
8
Table name
Revised program
The second header line reports field names. This line consists of a set of commadelimited strings that identify the name of individual fields as given in the
datalogger program. If the field is an element of an array, the name will be
followed by a comma-separated list of subscripts within parentheses that
identifies the array index. For example, a variable named Values, which is
declared as a two-by-two array in the datalogger program, will be represented by
IRXU¿HOGQDPHVValues(1,1), Values(1,2), Values(2,1), and Values(2,2). Scalar
variables will not have array subscripts. There will be one value on this line for
141
Section 7. Installation
HDFKVFDODUYDOXHGH¿QHGE\WKHWDEOH'HIDXOWILHOGQDPHVDUHDFRPELQDWLRQRI
the variable names (or alias) from which data are derived and a three-letter suffix.
The suffix is an abbreviation of the data process that outputs the data to storage.
For example, Avg is the abbreviation for the data process called by the Average()
instruction. If the default field names are not acceptable to the programmer,
FieldNames() instruction can be used to customize the names. TIMESTAMP,
RECORD, Batt_Volt_Avg, PTemp_C_Avg, TempC_Avg(1), and
TempC_Avg(2) are the default field names in the table Typical Data Table (p. 140).
The third-header line identifies engineering units for that field of data. These
units are declared at the beginning of a CRBasic program, as shown in CRBasic
example Definition and Use of a Data Table (p. 142). Units are strictly for
documentation. The CR1000 does not make use of declared units, nor does it
check their accuracy.
The fourth line of the header reports abbreviations of the data process used to
produce the field of data. See the table Data Process Abbreviations (p. 168).
Subsequent lines are observed data and associated record keeping. The first field
being a time stamp, and the second being the record (data line) number.
As shown in CRBasic example Definition and Use of a Data Table (p. 142), data
table declaration begins with the DataTable() instruction and ends with the
EndTable() instruction. Between DataTable() and EndTable() are instructions
that define what data to store and under what conditions data are stored. A data
table must be called by the CRBasic program for data storage processing to occur.
Typically, data tables are called by the CallTable() instruction once each Scan.
CRBasic Example 10.
Definition and Use of a Data Table
'This program example demonstrates definition and use of data tables.
'Declare Variables
Public Batt_Volt
Public PTemp_C
Public Temp_C(2)
'Define Units
Units Batt_Volt=Volts
Units PTemp_C=Deg_C
Units Temp_C()=Deg_C
'Define Data Tables
DataTable(OneMin,True,-1)
DataInterval(0,1,Min,10)
Average(1,Batt_Volt,FP2,False)
Average(1,PTemp_C,FP2,False)
Average(2,Temp_C(),FP2,False)
EndTable
'Required
'Optional
'Optional
'Optional
'Optional
'Required
beginning of data table declaration
instruction to trigger table at one-minute interval
instruction to average variable Batt_Volt
instruction to average variable PTemp_C
instruction to average variable Temp_C
end of data table declaration
DataTable(Table1,True,-1)
DataInterval(0,1440,Min,0) 'Optional instruction to trigger table at 24-hour interval
Minimum(1,Batt_Volt,FP2,False,False) 'Optional instruction to determine minimum Batt_Volt
EndTable
142
Section 7. Installation
'Main Program
BeginProg
Scan(5,Sec,1,0)
'Default Datalogger Battery Voltage measurement Batt_Volt:
Battery(Batt_Volt)
'Wiring Panel Temperature measurement PTemp_C:
PanelTemp(PTemp_C,_60Hz)
'Type T (copper-constantan) Thermocouple measurements Temp_C:
TCDiff(Temp_C(),2,mV2_5C,1,TypeT,PTemp_C,True,0,_60Hz,1,0)
'Call Data Tables and Store Data
CallTable(OneMin)
CallTable(Table1)
NextScan
EndProg
DataTable() / EndTable Instructions
The DataTable() instruction has three parameters: a user-specified alphanumeric
name for the table such as OneMin, a trigger condition (for example, True), and
the size to make the table in memory such as -1 (automatic allocation).
x
Name — The table name can be any combination of numbers, letters, and
underscore up to 20 characters in length. The first character must be a letter
or underscore.
Note While other characters may pass the precompiler and compiler, runtime
errors may occur if these naming rules are not adhered to.
x
TrigVar — Controls whether or not data records are written to storage. Data
records are written to storage if TrigVar is true and if other conditions, such
as DataInterval(), are met. Default setting is -1 (True). TrigVar may be a
variable, expression, or constant. TrigVar does not control intermediate
processing. Intermediate processing is controlled by the disable variable,
DisableVar, which is a parameter in all output processing instructions (see
section, Output Processing Instructions (p. 145) ).
Read More Section, TrigVar and DisableVar — Controlling Data Output and
Output Processing (p. 195) discusses the use of TrigVar and DisableVar in
special applications.
x
Size — Table size is the number of records to store in a table before new data
begins overwriting old data. If 10 is entered, 10 records are stored in the
table; the eleventh record will overwrite the first record. If –1 is entered,
memory for the table is allocated automatically at the time the program
compiles. Automatic allocation is preferred in most applications since the
CR1000 sizes all tables such that they fill (and begin overwriting the oldest
data) at about the same time. Approximately 2 kB of extra data-table space
are allocated to minimize the possibility of new data overwriting the oldest
data in ring memory when datalogger support software (p. 654) collects the
oldest data at the same time new data are written. These extra records are not
reported in the Status table and are not reported to the support software and
so are not collected.
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Section 7. Installation
Rules on table size change if a CardOut() instruction or TableFile()
instruction with Option 64 are included in the table declaration. These
instructions support writing of data to a memory card. Writing data to a card
requires additional memory be allocated as a data copy buffer. The CR1000
automatically determines the size the buffer needs to be (see Memory Cards
and Record Numbers (p. 466) ).
CRBasic example Definition and Use of a Data Table (p. 142) creates a data table
named OneMin, stores data once a minute as defined by DataInterval(), and
retains the most recent records in SRAM. DataRecordSize entries in the
DataTableInformation table report allocated memory in terms of number of
records the tables hold.
DataInterval() Instruction
DataInterval() instructs the CR1000 to both write data records at the specified
interval and to recognize when a record has been skipped. The interval is
independent of the Scan() / NextScan interval; however, it must be a multiple of
the Scan() / NextScan interval.
Sometimes, usually because of a timing issue, program logic prevents a record
from being written. If a record is not written, the CR1000 recognizes the omission
as a "lapse" and increments the SkippedRecord counter in the Status table.
Lapses waste significant memory in the data table and may cause the data table to
fill sooner than expected. DataInterval() instruction parameter Lapses controls
the CR1000 response to a lapse. See table DataInterval () Lapse Parameter
Options (p. 145) for more information.
Note Program logic that results in lapses includes scan intervals inadequate to the
length of the program (skipped scans), the use of DataInterval() in event-driven
data tables, and logic that directs program execution around the CallTable()
instruction.
A data table consists of successive 1 KB data frames. Each data frame contains a
time stamp, frame number, and one or more records. By default, a time stamp and
record number are not stored with each record. Rather, the datalogger support
software data extraction extraction routine uses the frame time stamp and frame
number to time stamp and number each record as it is stored to computer memory.
This technique saves telecommunication bandwidth and 16 bytes of CR1000
memory per record. However, when a record is skipped, or several records are
skipped contiguously, a lapse occurs, the SkippedRecords status entry is
incremented, and a 16-byte sub-header with time stamp and record number is
inserted into the data frame before the next record is written. Consequently,
programs that lapse frequently waste significant memory.
If Lapses is set to an argument of 20, the memory allocated for the data table is
increased by enough memory to accommodate 20 sub-headers (320 bytes). If
more than 20 lapses occur, the actual number of records that are written to the
data table before the oldest is overwritten (ring memory) may be less than what
was specified in the DataTable(), or the CF CardOut() instruction, or a
TableFile() instruction with Option 64.
If a program is planned to experience multiple lapses, and if telecommunication
bandwidth is not a consideration, the Lapses parameter should be set to 0 to
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Section 7. Installation
ensure the CR1000 allocates adequate memory for each data table.
Table 16. DataInterval() Lapse Parameter Options
DataInterval() Lapse
Argument
Effect
Lapse > 0
If table record number is fixed, X data frames (1 kB per data
frame) are added to data table if memory is available. If record
number is auto-allocated, no memory is added to table.
Lapse = 0
Time stamp and record number are always stored with each
record.
Lapse < 0
When lapse occurs, no new data frame is created. Record time
stamps calculated at data extraction may be in error.
Scan Time and System Time
In some applications, system time (see System Time (p. 530) ), rather than scan time
(see Scan Time (p. 527) ), is desired. To get the system time, the CallTable()
instruction must be run outside the Scan() loop. See section Time Stamps (p. 303).
OpenInterval() Instruction
By default, the CR1000 uses closed intervals. Data output to a data table based on
DataInterval() includes measurements from only the current interval.
Intermediate memory that contains measurements is cleared the next time the data
table is called regardless of whether or not a record was written to the data table.
Typically, time-series data (averages, totals, maxima, etc.), that are output to a
data table based on an interval, only include measurements from the current
interval. After each data-output interval, the memory that contains the
measurements for the time-series data are cleared. If a data-output interval is
missed (because all criteria are not met for output to occur), the memory is cleared
the next time the data table is called. If the OpenInterval instruction is contained
in the DataTable() declaration, the memory is not cleared. This results in all
measurements being included in the time-series data since the last time data were
stored (even though the data may span multiple data-output intervals).
Note Array-based dataloggers, such as CR10X and CR23X, use open intervals
exclusively.
Data-Output Processing Instructions
Data-storage processing instructions (aka, "output processing" instructions)
determine what data are stored in a data table. When a data table is called in the
CRBasic program, data-storage processing instructions process variables holding
current inputs or calculations. If trigger conditions are true, for example if the
data-output interval has expired, processed values are stored into the data table. In
CRBasic example Definition and Use of a Data Table (p. 142), three averages are
stored.
Consider the Average() instruction as an example data-storage processing
instruction. Average() stores the average of a variable over the data-output
interval. Its parameters are:
145
Section 7. Installation
x
x
x
Reps — number of sequential elements in the variable array for which
averages are calculated. Reps is set to 1 to average PTemp, and set to 2 to
average two thermocouple temperatures, both of which reside in the variable
array Temp_C.
Source — variable array to average. Variable arrays PTemp_C (an array of
1) and Temp_C() (an array of 2) are used.
DataType — Data type for the stored average (the example uses data type
FP2 (p. 641)).
Read More See Declaring Data Types (p. 130) for more information on available
data types.
x
DisableVar — controls whether a measurement or value is included in an
output processing function. A measurement or value is not included if
DisableVar is true 0). For example, if the disable variable in an
Average() instruction is true, the current value will not be included in the
average. CRBasic example Use of the Disable Variable (p. 146) and CRBasic
example Using NAN to Filter Data (p. 484) show how DisableVar can be used
to exclude values from an averaging process. In these examples, DisableVar
is controlled by Flag1. When Flag1 is high, or True, DisableVar is True.
When it is False, DisableVar is False. When False is entered as the
argument for DisableVar, all readings are included in the average. The
average of variable Oscillator does not include samples occurring when
Flag1 is high (True), which results in an average of 2; when Flag1 is low or
False (all samples used), the average is 1.5.
Read More TrigVar and DisableVar (p. 195)— Controlling Data Output and
Output Processing (p. 195) and Measurements and NAN (p. 482) discuss the use of
TrigVar and DisableVar in special applications.
Read More For a complete list of output processing instructions, see the section
Final Data (Output to Memory) Precessing (p. 542).
CRBasic Example 11.
Use of the Disable Variable
'This program example demonstrates the use of the 'disable' variable, or DisableVar, which
'is a parameter in many output processing instructions. Use of the 'disable' variable
'allows source data to be selectively included in averages, maxima, minima, etc. If the
''disable' variable equals -1, or true, data are not included; if equal to 0, or false,
'data are included. The 'disable' variable is set to false by default.
'Declare Variables and Units
Public Oscillator As Long
Public Flag(1) As Boolean
Public DisableVar As Boolean
'Define Data Tables
DataTable(OscAvgData,True,-1)
DataInterval(0,1,Min,10)
Average(1,Oscillator,FP2,DisableVar)
EndTable
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Section 7. Installation
'Main Program
BeginProg
Scan(1,Sec,1,0)
'Reset and Increment Counter
If Oscillator = 2 Then Oscillator = 0
Oscillator = Oscillator + 1
'Process and Control
If Oscillator = 1
If Flag(1) = True Then
DisableVar = True
EndIf
Else
DisableVar = False
EndIf
'Call Data Tables and Store Data
CallTable(OscAvgData)
NextScan
EndProg
Numbers of Records
The exact number of records that can be stored in a data table is governed by a
complex set of rules, the summary of which can be found in the appendix
Numbers of Records in Data Tables (p. 466).
7.8.4.10.2
Declaring Subroutines
Read More See section Subroutines (p. 288) for more information on programming
with subroutines.
Subroutines allow a section of code to be called by multiple processes in the main
body of a program. Subroutines are defined before the main program body of a
program.
Note A particular subroutine can be called by multiple program sequences
simultaneously. To preserve measurement and processing integrity, the CR1000
queues calls on the subroutine, allowing only one call to be processed at a time in
the order calls are received. This may cause unexpected pauses in the conflicting
program sequences.
7.8.4.10.3
'Include' File
An alternative to a subroutine is an 'include' file. An 'include' file is a CRBasic
program file that resides on the CR1000 CPU: drive and compiles as an insert to
the CRBasic program. It may also run on its own (p. 116). It is essentially a
subroutine stored in a file separate from the main program file. It can be used
once or multiple times by the main program, and by multiple programs. The file
begins with the SlowSequence instruction and can contain any code.
Procedure to use the "Include File":
1. Write the file, beginning with the SlowSequence instruction followed by any
other code.
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Section 7. Installation
2. Send the file to the CR1000 using tools in the File Control menu of datalogger
support software (p. 95).
3. Enter the path and name of the file in the Include File setting using DevConfig
or PakBusGraph.
Figures "Include File" Settings with DevConfig (p. 149) and "Include File" settings
with PakBusGraph (p. 149) show methods to set required settings with DevConfig or
with telecommunications. There is no restriction on the length of the file.
CRBasic example Using an "Include File" to Control Switched 12 V (p. 149) shows
a program that expects a file to control power to a modem; CRBasic example
"Include File" to Control Switched 12 V (p. 150) lists the code.
Consider the the example "include file", CPU:pakbus_broker.dld. The rules used
by the CR1000 when it starts are as follows:
1. If the logger is starting from power-up, any file that is marked as the "run on
power-up" program is the "current program". Otherwise, any file that is marked as
"run now" is selected. This behavior has always been present and is not affected
by this setting.
2. If there is a file specified by this setting, it is incorporated into the program
selected above.
3. If there is no current file selected or if the current file cannot be compiled, the
datalogger will run the program given by this setting as the current program.
4. If the program run by this setting cannot be run or if no program is specified,
the datalogger will attempt to run the program named default.cr1 on its CPU:
drive.
5. If there is no default.cr1 file or if that file cannot be compiled, the datalogger
will not run any program.
The CR1000 will now allow a SlowSequence statement to take the place of the
BeginProg statement. This feature allows the specified file to act both as an
include file and as the default program.
The formal syntax for this setting follows:
include-setting := device-name ":" file-name "." file-extension.
device-name
:= "CPU" | "USR" | "CRD"
File-extension := "dld" | "cr1"
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Section 7. Installation
Figure 40. "Include File" Settings Via DevConfig
Figure 41. "Include File" Settings Via PakBusGraph
CRBasic Example 1Ϯ.
Using an 'Include' File
'This program example demonstrates the use of an 'include' file. An 'include' file is a CRBasic
file that usually
'resides on the CPU: drive of the CR1000. It is essentially a subroutine that is
'stored in a file separate from the main program, but it compiles as an insert to the main
'program. It can be used once or multiple times, and by multiple programs.
''Include' files begin with the SlowSequence instruction and can contain any code.
'
'Procedure to use an 'include' file in this example:
'1. Copy the code from the CRbasic example 'Include' File to Control Switched 12 V (p. 150) to
149
Section 7. Installation
'
'
'
CRBasic Editor, name it 'IncludeFile.cr1, and save it to the same PC folder on which
resides the main program file (this make pre-compiling possible. Including the
SlowSequence instruction as the first statement is required, followed by any other code.
'2. Send the 'include' file to the CPU: drive of the CR1000 using the File Control menu
'
of the datalogger support software (p. 654). Be sure to de-select the Run Now and Run On
'
Power-up options that are presented by the software when sending the file.
'3. Add the Include instruction to the main CRBasic program at the location from which the
'
'include' file is to be called (see the following code).
'4. Enter the CR1000 file system path and file name after the Include() instruction, as shown
'
in the following code.
'
'IncludeFile.cr1 contains code to control power to a cellular phone modem.
'
'Cell phone + wire to be connected to SW12 terminal. Negative (-) wire
'to G.
Public PTemp, batt_volt
DataTable(Test,1,-1)
DataInterval(0,15,Sec,10)
Minimum(1,batt_volt,FP2,0,False)
Sample(1,PTemp,FP2)
EndTable
BeginProg
Scan(1,Sec,0,0)
PanelTemp(PTemp,250)
Battery(Batt_volt)
CallTable Test
NextScan
Include "CPU:IncludeFile.CR1" '<<<<<<<<<<<<<<<'include' file code executed here
EndProg
CRBasic Example 13.
'Include' File to Control SW1Ϯ Terminal.
'This program example demonstrates the use of an 'include' file. See the documentation in CRBasic
example
'Using an Include File (p. 149)
'
'<<<<<<<<<<<<<<<<<<<<<<<NOTE: No BeginProg instruction
SlowSequence '<<<<<<<<<<NOTE: Begins with SlowSequence
Scan(1,Sec,0,0)
If TimeIntoInterval(9,24,Hr) Then SW12(1)
'Modem on at 9:00 AM (900 hours)
If TimeIntoInterval(17,24,Hr) Then SW12(0) 'Modem off at 5:00 PM (1700 hours)
NextScan
'
'<<<<<<<<<<<<<<<<<<<<<<<NOTE: No EndProg instruction
7.8.4.10.4
Declaring Subroutines
Function() / EndFunction instructions allow you to create a customized CRBasic
instruction. The declaration is similar to a subroutine declaration.
7.8.4.10.5
Declaring Incidental Sequences
A sequence is two or more statements of code. Data-table sequences are essential
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Section 7. Installation
features of nearly all programs. Although used less frequently, subroutine and
function sequences also have a general purpose nature. In contrast, the following
sequences are used only in specific applications.
Shut-Down Sequences
The ShutDownBegin / ShutDownEnd instructions are used to define code that
will execute whenever the currently running program is shutdown by prescribed
means. More information is available in CRBasic Editor Help.
Dial Sequences
The DialSequence / EndDialSequence instructions are used to define the code
necessary to route packets to a PakBus® device. More information is available in
CRBasic Editor Help.
Modem-Hangup Sequences
The ModemHangup / EndModemHangup instructions are used to enclose code
that should be run when a COM port hangs up communication. More information
is available in CRBasic Editor Help.
Web-Page Sequences
The WebPageBegin / WebPageEnd instructions are used to declare a web page
that is displayed when a request for the defined HTML page comes from an
external source. More information is available in CRBasic Editor Help.
7.8.4.11 Execution and Task Priority
Execution of program instructions is divided among the following three tasks:
x
x
x
x
Measurement task — rigidly timed measurement of sensors connected
directly to the CR1000
CDM task — rigidly timed measurement and control of CDM (p. 509)
peripheral devices
SDM task — rigidly timed measurement and control of SDM (p. 527) peripheral
devices
Processing task — converts measurements to numbers represented by
engineering units, performs calculations, stores data, makes decisions to
actuate controls, and performs serial I/O communication.
Instructions or commands that are handled by each task are listed in table
Program Tasks (p. 152).
These tasks are executed in either pipeline or sequential mode. When in pipeline
mode, tasks run more or less in parallel. When in sequential mode, tasks run
more or less in sequence. When a program is compiled, the CR1000 evaluates the
program and automatically determines which mode to use. Using the
PipelineMode or SequentialMode instruction at the beginning of the program
will force the program into one mode or the other. Mode information is included
in a message returned by the datalogger, which is displayed by the datalogger
support software (p. 654). The CRBasic Editor pre-compiler returns a similar
message.
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Section 7. Installation
Note A program can be forced to run in sequential or pipeline mode by placing
the SequentialMode or PipelineMode instruction in the declarations section of
the program.
Some tasks in a program may have higher priorities than others. Measurement
tasks generally take precedence over all others. Task priorities are different for
pipeline mode and sequential mode.
Table 17. Program Tasks
Measurement Task
7.8.4.11.1
x
Analog
measurements
x
Excitation
x
Read pulse
counters
x
Read control ports
(GetPort())
x
Set control ports
(SetPort())
x
VibratingWire()
x
PeriodAvg()
x
CS616()
x
Calibrate()
Digital Task
x
x
SDM instructions,
except SDMSI04()
and SDMI016()
CDM instructions /
CPI devices.
Processing Task
x
Processing
x
Output
x
Serial I/O
x
SDMSIO4()
x
SDMIO16()
x
ReadIO()
x
WriteIO()
x
Expression evaluation and
variable setting in
measurement and SDM
instructions
Pipeline Mode
Pipeline mode handles measurement, most digital, and processing tasks
separately, and possibly simultaneously. Measurements are scheduled to execute
at exact times and with the highest priority, resulting in more precise timing of
measurement, and usually more efficient processing and power consumption.
Pipeline scheduling requires that the program be written such that measurements
are executed every scan. Because multiple tasks are taking place at the same time,
the sequence in which the instructions are executed may not be in the order in
which they appear in the program. Therefore, conditional measurements are not
allowed in pipeline mode. Because of the precise execution of measurement
instructions, processing in the current scan (including update of public variables
and data storage) is delayed until all measurements are complete. Some
processing, such as transferring variables to control instructions, like PortSet()
and ExciteV(), may not be completed until the next scan.
When a condition is true for a task to start, it is put in a queue. Because all tasks
are given the same priority, the task is put at the back of the queue. Every 10 ms
(or faster if a new task is triggered) the task currently running is paused and put at
the back of the queue, and the next task in the queue begins running. In this way,
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Section 7. Installation
all tasks are given equal processing time by the CR1000.
All tasks are given the same general priority. However, when a conflict arises
between tasks, program execution adheres to the priority schedule in table
Pipeline Mode Task Priorities (p. 153).
Table 18. Pipeline Mode Task Priorities
1. Measurements in main program
2. Background calibration
3. Measurements in slow sequences
4. Processing tasks
7.8.4.11.2
Sequential Mode
Sequential mode executes instructions in the sequence in which they are written in
the program. Sequential mode may be slower than pipeline mode since it executes
only one line of code at a time. After a measurement is made, the result is
converted to a value determined by processing arguments that are included in the
measurement command, and then program execution proceeds to the next
instruction. This line-by-line execution allows writing conditional measurements
into the program.
Note The exact time at which measurements are made in sequential mode may
vary if other measurements or processing are made conditionally, if there is heavy
communication activity, or if other interrupts, such as accessing a Campbell
Scientific mass storage device or memory card, occur.
When running in sequential mode, the datalogger uses a queuing system for
processing tasks similar to the one used in pipeline mode. The main difference
when running a program in sequential mode is that there is no pre-scheduling of
measurements; instead, all instructions are executed in the programmed order.
A priority scheme is used to avoid conflicting use of measurement hardware. The
main scan has the highest priority and prevents other sequences from using
measurement hardware until the main scan, including processing, is complete.
Other tasks, such as processing from other sequences and communications, can
occur while the main sequence is running. Once the main scan has finished, other
sequences have access to measurement hardware with the order of priority being
the background calibration sequence followed by the slow sequences in the order
they are declared in the program.
Note Measurement tasks have priority over other tasks such as processing and
communication to allow accurate timing needed within most measurement
instructions.
Care must be taken when initializing variables when multiple sequences are used
in a program. If any sequence relies on something (variable, port, etc.) that is
initialized in another sequence, there must be a handshaking scheme placed in the
CRBasic program to make sure that the initializing sequence has completed
before the dependent task can proceed. This can be done with a simple variable or
even a delay, but understand that the CR1000 operating system will not do this
handshaking between independent tasks.
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Section 7. Installation
A similar concern is the reuse of the same variable in multiple tasks. Without
some sort of messaging between the two tasks placed into the CRBasic program,
unpredictable results are likely to occur. The SemaphoreGet() and
SemaphoreRelease() instruction pair provide a tool to prevent unwanted access
of an object (variable, COM port, etc.) by another task while the object is in use.
Consult CRBasic Editor Help for information on using SemaphoreGet() and
SemaphoreRelease().
7.8.4.12 Execution Timing
Timing of program execution is regulated by timing instructions listed in the
following table.
Table 19. Program Timing Instructions
Instructions
7.8.4.12.1
General Guidelines
Scan() / NextScan
Use in most programs. Begins
/ ends the main scan.
SlowSequence /
EndSequence
Use when measurements or
processing must run at slower
frequencies than that of the
main program.
SubScan / NextSubScan
Use when measurements or
processing must run at faster
frequencies than that of the
main program.
Syntax Form
BeginProg
Scan()
'.
'.
'.
NextScan
EndProg
BeginProg
Scan()
'.
'.
'.
NextScan
SlowSequence
Scan()
'.
'.
'.
NextScan
EndSequence
EndProg
BeginProg
Scan()
'.
'.
'.
SubScan()
'.
'.
'.
NextSubScan
NextScan
EndProg
Scan() / NextScan
Simple CR1000 programs are often built entirely within a single Scan() /
NextScan structure, with only variable and data-table declarations outside the
scan. Scan() / NextScan creates an infinite loop; each periodic pass through the
loop is synchronized to the CR1000 clock. Scan() parameters allow modification
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Section 7. Installation
of the period in 10 ms increments up to 24 hours. As shown in CRBasic example
BeginProg / Scan() / NextScan / EndProg Syntax (p. 155), the CRBasic program
may be relatively short.
CRBasic Example 14.
BeginProg / Scan() / NextScan / EndProg Syntax
'This program example demonstrates the use of BeginProg/EndProg and Scan()/NextScan syntax.
Public PanelTemp_
DataTable(PanelTempData,True,-1)
DataInterval(0,1,Min,10)
Sample(1,PanelTemp_,FP2)
EndTable
BeginProg '
<<<<<<<BeginProg
Scan(1,Sec,3,0) '
<<<<<<< Scan
PanelTemp(PanelTemp_,250)
CallTable PanelTempData
NextScan '
<<<<<<< NextScan
EndProg '
<<<<<<<EndProg
Scan() determines how frequently instructions in the program are executed, as
shown in the following CRBasic code snip:
'Scan(Interval, Units, BufferSize, Count)
Scan(1,Sec,3,0)
'CRBasic instructions go here
ExitScan
Scan() has four parameters:
x
x
x
x
7.8.4.12.2
Interval — WKHLQWHUYDOEHWZHHQVFDQV,QWHUYDOLVPV”Interval ”1 day.
Units — the time unit for the interval.
BufferSize — the size (number of scans) of a buffer in RAM that holds the
raw results of measurements. When running in pipeline mode, using a buffer
allows the processing in the scan to lag behind measurements at times
without affecting measurement timing. Use of the CRBasic Editor default
size is normal. Refer to section SkippedScan (p. 487) for troubleshooting tips.
Count — number of scans to make before proceeding to the instruction
following NextScan. A count of 0 means to continue looping forever (or until
ExitScan). In the example in CRBasic example Scan Syntax, the scan is one
second, three scans are buffered, and measurements and data storage continue
indefinitely.
SlowSequence / EndSequence
Slow sequences include automatic and user entered sequences. Background
calibration is an automatic slow sequence. A
User-entered slow sequences are declared with the SlowSequence instruction and
run outside the main-program scan. Slow sequences typically run at a slower rate
than the main scan. Up to four slow-sequence scans can be defined in a program.
Instructions in a slow-sequence scan are executed when the main scan is not
active. When running in pipeline mode, slow-sequence measurements are spliced
in after measurements in the main program, as time allows. Because of this
splicing, measurements in a slow sequence may span across multiple-scan
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Section 7. Installation
intervals in the main program. When no measurements need to be spliced, the
slow-sequence scan will run independent of the main scan, so slow sequences
with no measurements can run at intervals d main-scan interval (still in 10 ms
increments) without skipping scans. When measurements are spliced, checking
for skipped slow scans is done after the first splice is complete rather than
immediately after the interval comes true.
In sequential mode, all instructions in slow sequences are executed as they occur
in the program according to task priority.
Background calibration is an automatic, slow-sequence scan, as is the watchdog
task.
Read More See the section CR1000 Auto Calibration — Overview (p. 92).
7.8.4.12.3
SubScan() / NextSubScan
SubScan() / NextSubScan are used in the control of analog multiplexers (see the
appendix Analog Multiplexers (p. 646) for information on available analog
multiplexers) or to measure analog inputs at a faster rate than the program scan.
SubScan() / NextSubScan can be used in a SlowSequenc / EndSequence with
an interval of 0. SubScan cannot be nested. PulseCount or SDM measurement
cannot be used within a sub scan.
7.8.4.12.4
Scan Priorities in Sequential Mode
Note Measurement tasks have priority over other tasks such as processing and
communication to allow accurate timing needed within most measurement
instructions.
A priority scheme is used in sequential mode to avoid conflicting use of
measurement hardware. As illustrated in figure Sequential-Mode Scan Priority
Flow Diagrams (p. 158), the main scan sequence has the highest priority. Other
sequences, such as slow sequences and calibration scans, must wait to access
measurement hardware until the main scan, including measurements and
processing, is complete.
Main Scans
Execution of the main scan usually occurs quickly, so the processor may be idle
much of the time. For example, a weather-measurement program may scan once
per second, but program execution may only occupy 250 ms, leaving 75% of
available scan time unused. The CR1000 can make efficient use of this interstitialscan time to optimize program execution and communication control. Unless
disabled, or crowded out by a too demanding schedule, self-calibration (see
CR1000 Auto Calibration — Overview (p. 92)) has priority and uses some
interstitial scan time. If self-calibration is crowded out, a warning message is
issued by the CRBasic pre-compiler. Remaining priorities include slow-sequence
scans in the order they are programmed and digital triggers. Following is a brief
introduction to the rules and priorities that govern use of interstitial-scan time in
sequential mode. Rules and priorities governing pipeline mode are somewhat
more complex and are not expanded upon.
Permission to proceed with a measurement is granted by the measurement
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Section 7. Installation
semaphore (p. 527). Main scans with measurements have priority to acquire the
semaphore before measurements in a calibration or slow-sequence scan. The
semaphore is taken by the main scan at its beginning if there are measurements
included in the scan. The semaphore is released only after the last instruction in
the main scan is executed.
Slow-Sequence Scans
Slow-sequence scans begin after a SlowSequence instruction. They start
processing tasks prior to a measurement but stop to wait when a measurement
semaphore is needed. Slow sequences release the semaphore (p. 527) after complete
execution of each measurement instruction to allow the main scan to acquire the
semaphore when it needs to start. If the measurement semaphore is set by a slowsequence scan and the beginning of a main scan gets to the top of the queue, the
main scan will not start until it can acquire the semaphore; it waits for the slow
sequence to release the semaphore. A slow-sequence scan does not hold the
semaphore for the whole of its scan. It releases the semaphore after each use of
the hardware.
WaitDigTrig Scans
Read More See Synchronizing Measurements (p. 365).
Main scans and slow sequences usually trigger at intervals defined by the Scan()
instruction. Some applications, however, require the main- or slow-sequence scan
to be started by an external digital trigger such as a 5 Vdc pulse on a control port.
The WaitDigTrig() instruction activates a program when an external trigger is
detected. WaitDigTrig() gives priority to begin a scan, but the scan will execute
and acquire the semaphore (p. 527) according to the rules stated in Main Scans (p. 156)
and Slow-Sequence Scans (p. 157). Any processing will be time sliced with
processing from other sequences. Every time the program encounters
WaitDigTrig(), it will stop and wait to be triggered.
Note WaitDigTrig() can be used to program a CR1000 to control another
CR1000.
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Section 7. Installation
Figure 42. Sequential-Mode Scan Priority Flow Diagrams
7.8.4.13 Programming Instructions
In addition to BASIC syntax, additional instructions are included in CRBasic to
facilitate measurements and store data. The section CRBasic Programming
Instructions (p. 537) contains a comprehensive list of these instructions.
7.8.4.13.1
Measurement and Data-Storage Processing
CRBasic instructions have been created for making measurements and storing
data. Measurement instructions set up CR1000 hardware to make measurements
and store results in variables. Data-storage instructions process measurements into
averages, maxima, minima, standard deviation, FFT, etc.
Each instruction is a keyword followed by a series of informational parameters
needed to complete the procedure. For example, the instruction for measuring
CR1000 panel temperature is:
PanelTemp(Dest,Integ)
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Section 7. Installation
PanelTemp is the keyword. Two parameters follow: Dest, a destination variable
name in which the temperature value is stored; and Integ, a length of time to
integrate the measurement. To place the panel temperature measurement in the
variable RefTemp, using a 250 μs integration time, the syntax is as shown in
CRBasic example Measurement Instruction Syntax (p. 159).
CRBasic Example 1ϱ.
Measurement Instruction Syntax
'This program example demonstrates the use of a single measurement instruction.
'case, the program measures the temperature of the CR1000 wiring panel.
In this
Public RefTemp 'Declare variable to receive instruction
BeginProg
Scan(1,Sec,3,0)
PanelTemp(RefTemp, 250) '<<<<<<Instruction to make measurement
NextScan
EndProg
7.8.4.13.2
Argument Types
Most CRBasic commands or instructions, have sub-commands or parameters.
Parameters are populated by the programmer with arguments. Many instructions
have parameters that allow different types of arguments. Common argument types
are listed below. Allowed argument types are specifically identified in the
description of each instruction in CRBasic Editor Help.
x
x
x
x
x
x
x
x
x
7.8.4.13.3
Constant, or Expression that evaluates as a constant
Variable
Variable or Array
Constant, Variable, or Expression
Constant, Variable, Array, or Expression
Name
Name or list of Names
Variable, or Expression
Variable, Array, or Expression
Names in Arguments
Table Rules for Names (p. 159) lists the maximum length and allowed characters for
the names for variables, arrays, constants, etc. The CRBasic Editor pre-compiler
will identify names that are too long or improperly formatted.
Caution Concerning characters allowed in names, characters not listed in in the
table, Rules for Names, may appear to be supported in a specific operating system.
However, they may not be supported in future operating systems.
Table 20. Rules for Names
Name
Category
1
Maximum Length
(number of
characters)
Variable or array
39
Constant
38
Allowed characters
Letters A to Z, a to z, _ (underscore), and
numbers 0 to 9. Names must start with a letter
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Section 7. Installation
Table 20. Rules for Names
Name
Category
1
Maximum Length
(number of
characters)
Units
38
Alias
39
Station name
64
Data-table name
20
Field name
39
Field-name
description
64
Allowed characters
or underscore. CRBasic is not case sensitive.
Units are excepted from the above rules. Since
units are strings that ride along with the data,
they are not subjected to the stringent syntax
checking that is applied to variables, constants,
subroutines, tables, and other names.
1
Variables, constants, units, aliases, station names, field names, data table names, and file names
can share identical names; that is, once a name is used, it is reserved only in that category. See
the section Predefined Constants (p. 138) for another naming limitation.
7.8.4.14 Expressions in Arguments
Read More See Programming Express Types (p. 160) for more information on
expressions.
Many CRBasic instruction parameters allow the entry of arguments as
expressions. If an expression is a comparison, it will return -1 if true and 0 if false.
(See the section Logical Expressions (p. 164)). The following code snip shows the
use of an expressions as an argument in the TrigVar parameter of the
DataTable() instruction:
'DataTable(Name, TrigVar, Size)
DataTable(Temp, TC > 100, 5000)
When the trigger is TC > 100, a thermocouple temperature greater than 100 sets
the trigger to True and data are stored.
7.8.4.15 Programming Expression Types
An expression is a series of words, operators, or numbers that produce a value or
result. Expressions are evaluated from left to right, with deference to precedence
rules. The result of each stage of the evaluation is of type Long (integer, 32 bits) if
the variables are of type Long (constants are integers) and the functions give
integer results, such as occurs with INTDV(). If part of the equation has a
floating point variable or constant (24 bits), or a function that results in a floating
point, the rest of the expression is evaluated using floating-point, 24-bit math,
even if the final function is to convert the result to an integer, so precision can be
lost; for example, INT((rtYear-1993)*.25). This is a critical feature to consider
when, 1) trying to use integer math to retain numerical resolution beyond the limit
of floating point variables, or 2) if the result is to be tested for equivalence against
another value. See section Floating-Point Arithmetic (p. 161) for limits.
Two types of expressions, mathematical and programming, are used in CRBasic.
A useful property of expressions in CRBasic is that they are equivalent to and
often interchangeable with their results.
160
Section 7. Installation
Consider the expressions:
x = (z * 1.8) + 32 '(mathematical expression)
If x = 23 then y = 5 '(programming expression)
The variable x can be omitted and the expressions combined and written as:
If (z * 1.8 + 32 = 23) then y = 5
Replacing the result with the expression should be done judiciously and with the
realization that doing so may make program code more difficult to decipher.
7.8.4.15.1
Floating-Point Arithmetic
Variables and calculations are performed internally in single-precision IEEE fourbyte floating point with some operations calculated in double precision.
Note Single-precision float has 24 bits of mantissa. Double precision has a 32-bit
extension of the mantissa, resulting in 56 bits of precision. Instructions that use
double precision are AddPrecise(), Average(), AvgRun(), AvgSpa(), CovSpa(),
MovePrecise(), RMSSpa(), StdDev(), StdDevSpa(), Totalize(), and TotRun().
Floating-point arithmetic is common in many electronic, computational systems,
but it has pitfalls high-level programmers should be aware of. Several sources
discuss floating-point arithmetic thoroughly. One readily available source is the
topic Floating Point at www.wikipedia.org. In summary, CR1000 programmers
should consider at least the following:
x
x
x
x
7.8.4.15.2
Floating-point numbers do not perfectly mimic real numbers.
Floating-point arithmetic does not perfectly mimic true arithmetic.
Avoid use of equality in conditional statements. Use >= and <= instead. For
example, use If X >= Y then do rather than If X = Y then do.
When programming extended-cyclical summation of non-integers, use the
AddPrecise() instruction. Otherwise, as the size of the sum increases,
fractional addends will have an ever decreasing effect on the magnitude of
the sum, because normal floating-point numbers are limited to about 7 digits
of resolution.
Mathematical Operations
Mathematical operations are written out much as they are algebraically. For
example, to convert Celsius temperature to Fahrenheit, the syntax is:
TempF = TempC * 1.8 + 32
Read More Code space can be conserved while filling an array or partial array
with the same value. See an example of how this is done in the CRBasic example
Use of Move() to Conserve Code Space. CRBasic example Use of Variable
Arrays to Conserve Code Space (p. 162) shows example code to convert twenty
temperatures in a variable array from °C to °F.
161
Section 7. Installation
CRBasic Example 16.
Use of Move() to Conserve Code Space
Move(counter(1),6,0,1)
Move(TempC(2),9,TempC(1),9)
'Reset six counters to zero. Keep array
'filled with the ten most current readings
'Shift previous nine readings to make room
'for new measurement
'New measurement:
TCDiff(TempC(1),1,mV2_5C,8,TypeT,PTemp,True,0,_60Hz,1.0,0)
CRBasic Example 17.
Use of Variable Arrays to Conserve Code Space
For I = 1 to 20
TCTemp(I) = TCTemp(I) * 1.8 + 32
Next I
7.8.4.15.3
Expressions with Numeric Data Types
FLOATs, LONGs and Booleans are cross-converted to other data types, such as
FP2, by using '='.
Boolean from FLOAT or LONG
When a FLOAT or LONG is converted to a Boolean as shown in CRBasic
example Conversion of FLOAT / LONG to Boolean (p. 162), zero becomes false (0)
and non-zero becomes true (-1).
CRBasic Example 18.
Conversion of FLOAT / LONG to Boolean
'This program example demonstrates conversion of Float and Long data types to Boolean
'data type.
Public
Public
Public
Public
Public
Public
Fa As Float
Fb As Float
L As Long
Ba As Boolean
Bb As Boolean
Bc As Boolean
BeginProg
Fa = 0
Fb = 0.125
L = 126
Ba = Fa
Bb = Fb
Bc = L
EndProg
'This will set Ba = False (0)
'This will Set Bb = True (-1)
'This will Set Bc = True (-1)
FLOAT from LONG or Boolean
When a LONG or Boolean is converted to FLOAT, the integer value is loaded
into the FLOAT. Booleans are converted to -1 or 0. LONG integers greater than
24 bits (16,777,215; the size of the mantissa for a FLOAT) will lose resolution
when converted to FLOAT.
LONG from FLOAT or Boolean
When converted to Long, Boolean is converted to -1 or 0. When a FLOAT is
162
Section 7. Installation
converted to a LONG, it is truncated. This conversion is the same as the INT
function (Arithmetic Functions (p. 568) ). The conversion is to an integer equal to or
less than the value of the float; for example, 4.6 becomes 4 and –4.6 becomes –5).
If a FLOAT is greater than the largest allowable LONG (+2,147,483,647), the
integer is set to the maximum. If a FLOAT is less than the smallest allowable
LONG (–2,147,483,648), the integer is set to the minimum.
Integers in Expressions
LONGs are evaluated in expressions as integers when possible. CRBasic example
Evaluation of Integers (p. 163) illustrates evaluation of integers as LONGs and
FLOATs.
CRBasic Example 19.
Evaluation of Integers
'This program example demonstrates the evaluation of integers.
Public I As Long
Public X As Float
BeginProg
I = 126
X = (I+3) * 3.4
'I+3 is evaluated as an integer, then converted to Float data type before it is
'multiplied by 3.4.
EndProg
Constants Conversion
Constants are not declared with a data type, so the CR1000 assigns the data type
as needed. If a constant (either entered as a number or declared with CONST) can
be expressed correctly as an integer, the compiler will use the type that is most
efficient in each expression. The integer version is used if possible, for example, if
the expression has not yet encountered a FLOAT. CRBasic example Constants to
LONGs or FLOATs (p. 163) lists a programming case wherein a value normally
considered an integer (10) is assigned by the CR1000 to be As FLOAT.
CRBasic Example Ϯ0.
Constants to LONGs or FLOATs
'This program example demonstrates conversion of constants to Long or Float data types.
Public L As Long
Public F1 As Float
Public F2 As Float
Const ID = 10
BeginProg
F1 = F2 + ID
L = ID * 5
EndProg
In CRBasic example Constants to LONGs or FLOATs (p. 163), I is an integer. A1
and A2 are FLOATS. The number 5 is loaded As FLOAT to add efficiently with
constant ID, which was compiled As FLOAT for the previous expression to avoid
an inefficient runtime conversion from LONG to FLOAT before each floating
point addition.
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Section 7. Installation
7.8.4.15.4
Logical Expressions
Measurements can indicate absence or presence of an event. For example, an RH
measurement of 100% indicates a condensation event such as fog, rain, or dew.
The CR1000 can render the state of the event into binary form for further
processing, so the event is either occurring (true), or the event has not occurred
(false).
True = -1, False = 0
In all cases, the argument 0 is translated as FALSE in logical expressions; by
extension, any non-zero number is considered "non-FALSE." However, the
argument TRUE is predefined in the CR1000 operating system to only equal -1,
so only the argument -1 is always translated as TRUE. Consider the expression
If Condition(1) = TRUE Then...
This condition is true only when Condition(1) = -1. If Condition(1) is any other
non-zero, the condition will not be found true because the constant TRUE is
predefined as -1 in the CR1000 system memory. By entering = TRUE, a literal
comparison is done. So, to be absolutely certain a function is true, it must be set
to TRUE or -1.
Note TRUE is -1 so that every bit is set high (-1 is &B11111111 for all four
bytes). This allows the AND operation to work correctly. The AND operation
does an AND boolean function on every bit, so TRUE AND X will be non-zero if
at least one of the bits in X is non-zero (if X is not zero). When a variable of data
type BOOLEAN is assigned any non-zero number, the CR1000 internally
converts it to -1.
The CR1000 is able to translate the conditions listed in table Binary Conditions of
TRUE and FALSE (p. 164) to binary form (-1 or 0), using the listed instructions and
saving the binary form in the memory location indicated. Table Logical
Expression Examples (p. 165) explains some logical expressions.
Non-Zero = True (Sometimes)
Any argument other than 0 or -1 will be translated as TRUE in some cases and
FALSE in other cases. While using only -1 as the numerical representation of
TRUE is safe, it may not always be the best programming technique. Consider
the expression
If Condition(1) then...
Since = True is omitted from the expression, Condition(1) is considered true if it
equals any non-zero value.
164
Section 7. Installation
Table 21. Binary Conditions of TRUE and FALSE
CRBasic Instruction(s)
Used
Condition
Time
Memory Location of Binary
Result
TimeIntoInterval()
Variable, System
IfTime()
Variable, System
TimeIsBetween()
Variable, System
Control Port Trigger
WaitDigTrig()
System
Communications
VoiceBeg()
System
ComPortIsActive()
Variable
PPPClose()
Variable
DataEvent()
System
Measurement Event
Using TRUE or FALSE conditions with logic operators such as AND and OR,
logical expressions can be encoded to perform one of the following three general
logic functions. Doing so facilitates conditional processing and control
applications:
1. Evaluate an expression, take one path or action if the expression is true (= –1),
and / or another path or action if the expression is false (= 0).
2. Evaluate multiple expressions linked with AND or OR.
3. Evaluate multiple AND or OR links.
The following commands and logical operators are used to construct logical
expressions. CRBasic example Logical Expression Examples (p. 165) demonstrate
some logical expressions.
x
x
x
x
x
x
x
IF
AND
OR
NOT
XOR
IMP
IIF
Table 22. Logical Expression Examples
If X >= 5 then Y = 0
Sets the variable Y to 0 if the expression "X >= 5" is true, i.e. if X is greater than or equal to 5. The CR1000 evaluates the
expression (X >= 5) and registers in system memory a -1 if the expression is true, or a 0 if the expression is false.
If X >= 5 OR Z = 2 then Y = 0
Sets Y = 0 if either X >= 5 or Z = 2 is true.
If X >= 5 AND Z = 2 then Y = 0
Sets Y = 0 only if both X >= 5 and Z = 2 are true.
If 6 then Y = 0.
If 6 is true since 6 (a non-zero number) is returned, so Y is set to 0 every time the statement is executed.
If 0 then Y = 0.
If 0 is false since 0 is returned, so Y will never be set to 0 by this statement.
Z = (X > Y).
Z equals -1 if X > Y, or Z will equal 0 if X <= Y.
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Section 7. Installation
Table 22. Logical Expression Examples
The NOT operator complements every bit in the word. A Boolean can be FALSE (0 or all bits set to 0) or TRUE (-1 or all bits set to 1).
“Complementing” a Boolean turns TRUE to FALSE (all bits complemented to 0).
Example Program
'(a AND b) = (26 AND 26) = (&b11010 AND &b11010) =
'&b11010. NOT (&b11010) yields &b00101.
'This is non-zero, so when converted to a
'BOOLEAN, it becomes TRUE.
Public a As LONG
Public b As LONG
Public is_true As Boolean
Public not_is_true As Boolean
Public not_a_and_b As Boolean
BeginProg
a = 26
b = a
Scan (1,Sec,0,0)
is_true = a AND b
'This evaluates to TRUE.
not_is_true = NOT (is_true) 'This evaluates to FALSE.
not_a_and_b = NOT (a AND b) 'This evaluates to TRUE!
NextScan
EndProg
7.8.4.15.5
String Expressions
CRBasic facilitates concatenation of string variables to variables of all data types
using & and + operators. To ensure consistent results, use & when concatenating
strings. Use + when concatenating strings to other variable types. CRBasic
example String and Variable Concatenation (p. 166) demonstrates CRBasic code for
concatenating strings and integers. See section String Operations (p. 282) in the
Programming Resource Library (p. 169) for more information on string
programming.
CRBasic Example Ϯ1.
String and Variable Concatenation
'This program example demonstrates the concatenation of variables declared As String to
'other strings and to variables declared as other data types.
'
'Declare Variables
Dim PhraseNum(2) As Long
Dim Word(15) As String * 10
Public Phrase(2) As String * 80
'Declare Data Table
DataTable(HAL,1,-1)
DataInterval(0,15,Sec,10)
'Write phrases to data table "Test"
Sample(2,Phrase,String)
EndTable
166
Section 7. Installation
'Program
BeginProg
Scan(1,Sec,0,0)
'Assign strings to String variables
Word(1) = "Good"
Word(2) = "morning"
Word(3) = "Dave"
Word(4) = "I'm"
Word(5) = "sorry"
Word(6) = "afraid"
Word(7) = "I"
Word(8) = "can't"
Word(9) = "do"
Word(10) = "that"
Word(11) = " "
Word(12) = ","
Word(13) = ";"
Word(14) = "."
Word(15) = Chr(34)
'Assign integers to Long variables
PhraseNum(1) = 1
PhraseNum(2) = 2
'Concatenate string "1. Good morning, Dave"
Phrase(1) = PhraseNum(1)+Word(14)+Word(11)&Word(15)&Word(1)&Word(11)&Word(2)& _
Word(12)&Word(11)&Word(3)&Word(14)&Word(15)
'Concatenate string "2. I'm afraid I can't do that, Dave."
Phrase(2) = PhraseNum(2)+Word(14)&Word(11)&Word(15)&Word(4)&Word(11)&Word(6)&Word(11)& _
Word(7)&Word(11)&Word(8)&Word(11)&Word(9)&Word(11)&Word(10)&Word(12)& _
Word(11)&Word(3)&Word(14)&Word(15)
CallTable HAL
NextScan
EndProg
7.8.4.16 Programming Access to Data Tables
A data table is a memory location where data records are stored. Sometimes, the
stored data needs to be used in the CRBasic program. For example, a program
can be written to retrieve the average temperature of the last five days for further
processing. CRBasic has syntax provisions facilitating access to these table data,
or to meta data relating to the data table. Except when using the GetRecord()
instruction (Data Table Access and Management (p. 592) ), the syntax is entered
directly into the CRBasic program through a variable name. The general form is:
TableName.FieldName_Prc(Fieldname Index, Records Back)
Where:
x
x
x
TableName is the name of the data table.
FieldName is the name of the variable from which the processed value is
derived.
Prc is the abbreviation of the name of the data process used. See table Data
Process Abbreviations (p. 168) for a complete list of these abbreviations. This is
not needed for values from Status or Public tables.
167
Section 7. Installation
x
x
Fieldname Index is the array element number in fields that are arrays
(optional).
Records Back is how far back into the table to go to get the value (optional).
If left blank, the most recent record is acquired.
Table 23. Data Process Abbreviations
Abbreviation
Process Name
Tot
Totalize
Avg
Average
Max
Maximum
Min
Minimum
SMM
Sample at Max or Min
Std
Standard Deviation
MMT
Moment
No abbreviation
Sample
1
Hst
Histogram
H4D
Histogram4D
FFT
FFT
Cov
Covariance
RFH
Rainflow Histogram
LCr
Level Crossing
WVc
WindVector
Med
Median
ETsz
ET
RSo
Solar Radiation (from ET)
TMx
Time of Max
TMn
Time of Min
1
Hst is reported in the form Hst,20,1.0000e+00,0.0000e+00,1.0000e+01 where Hst denotes a
histogram, 20 = 20 bins, 1 = weighting factor, 0 = lower bound, 10 = upper bound.
For example, to access the number of watchdog errors, use the statement
wderr = status.watchdogerrors
where wderr is a declared variable, status is the table name, and watchdogerrors
is the keyword for the watchdog error field.
Seven special variable names are used to access information about a table.
x
x
x
x
x
x
x
168
EventCount
EventEnd
Output
Record
TableFull
TableSize
TimeStamp
Section 7. Installation
Consult CRBasic Editor Help index topic DataTable access for complete
information.
The DataTableInformation table also include this information. See Status,
Settings, and Data Table Information (Status/Settings/DTI) (p. 603).
7.8.4.17 Programming to Use Signatures
Signatures help assure system integrity and security. The following resources
provide information on using signatures.
x
x
x
x
x
Signature() instruction in Diagnostics (p. 550)
RunSignature entry in table Signature Status/Settings/DTI (p. 603)
ProgSignature entry in table Signature Status/Settings/DTI (p. 603)
OSSignature entry in table Signature Status/Settings/DTI (p. 603)
Security (p. 92)
Many signatures are recorded in the Status table, which is a type of data table.
Signatures recorded in the Status table can be copied to a variable using the
programming technique described in the Programming Access to Data Tables (p.
167). Once in variable form, signatures can be sampled as part of another data
table for archiving.
7.9
Programming Resource Library
This library of notes and CRBasic code addresses a narrow selection of CR1000
applications. Consult a Campbell Scientific application engineer if other
resources are needed.
7.9.1
Advanced Programming Techniques
7.9.1.1 Capturing Events
CRBasic example Capturing Events (p. 169) demonstrates programming to output
data to a data table at the occurrence of an event.
CRBasic Example ϮϮ.
BeginProg / Scan / NextScan / EndProg Syntax
'This program example demonstrates detection and recording of an event. An event has a
'beginning and an end. This program records an event as occurring at the end of the event.
'The event recorded is the transition of a delta temperature above 3 degrees. The event is
'recorded when the delta temperature drops back below 3 degrees.
'The DataEvent instruction forces a record in data table Event each time an
'event ends. Number of events is written to the reserved variable
'EventCount(1,1). In this program, EventCount(1,1) is recorded in the
'OneMinute Table.
'Note : the DataEvent instruction must be used within a data table with a
'more frequent record interval than the expected frequency of the event.
'Declare Variables
Public PTemp_C, AirTemp_C, DeltaT_C
Public EventCounter
169
Section 7. Installation
'Declare Event Driven Data Table
DataTable(Event,True,1000)
DataEvent(0,DeltaT_C>=3,DeltaT_C<3,0)
Sample(1,PTemp_C, FP2)
Sample(1,AirTemp_C, FP2)
Sample(1,DeltaT_C, FP2)
EndTable
'Declare Time Driven Data Table
DataTable(OneMin,True,-1)
DataInterval(0,1,Min,10)
Sample(1,EventCounter, FP2)
EndTable
BeginProg
Scan(1,Sec,1,0)
'Wiring Panel Temperature
PanelTemp(PTemp_C,_60Hz)
'Type T Thermocouple measurements:
TCDiff(AirTemp_C,1,mV2_5C,1,TypeT,PTemp_C,True,0,_60Hz,1,0)
'Calculate the difference between air and panel temps
DeltaT_C = AirTemp_C - PTemp_C
'Update Event Counter (uses special syntax Event.EventCount(1,1))
EventCounter = Event.EventCount(1,1)
'Call data table(s)
CallTable(Event)
CallTable(OneMin)
NextScan
EndProg
7.9.1.2 Conditional Output
CRBasic example Conditional Output (p. 170) demonstrates programming to output
data to a data table conditional on a trigger other than time.
CRBasic Example Ϯ3.
Conditional Output
'This program example demonstrates the conditional writing of data to a data table.
'also demonstrates use of StationName() and Units instructions.
'Declare Station Name (saved to Status table)
StationName(Delta_Temp_Station)
'Declare Variables
Public PTemp_C, AirTemp_C, DeltaT_C
170
It
Section 7. Installation
'Declare Units
Units PTemp_C = deg C
Units AirTemp_C = deg C
Units DeltaT_C = deg C
'Declare Output Table -- Output Conditional on Delta T >=3
'Table stores data at the Scan rate (once per second) when condition met
'because DataInterval instruction is not included in table declaration.
DataTable(DeltaT,DeltaT_C >= 3,-1)
Sample(1,Status.StationName,String)
Sample(1,DeltaT_C,FP2)
Sample(1,PTemp_C,FP2)
Sample(1,AirTemp_C,FP2)
EndTable
BeginProg
Scan(1,Sec,1,0)
'Measure wiring panel temperature
PanelTemp(PTemp_C,_60Hz)
'Measure type T thermocouple
TCDiff(AirTemp_C,1,mV2_5C,1,TypeT,PTemp_C,True,0, _60Hz,1,0)
'Calculate the difference between air and panel temps
DeltaT_C = AirTemp_C - PTemp_C
'Call data table(s)
CallTable(DeltaT)
NextScan
EndProg
7.9.1.3 Groundwater Pump Test
CRBasic example Groundwater Pump Test (p. 171) demonstrates:
x
x
x
x
How to write multiple-interval data to the same data table
Use of program-control instructions outside the Scan() / NextScan structure
One way to execute conditional code
Use of multiple sequential scans, each with a scan count
171
Section 7. Installation
CRBasic Example Ϯ4.
Groundwater Pump Test
'This program example demonstrates the use of multiple scans in a program by running a
'groundwater pump test. Note that Scan() time units of Sec have been changed to mSec for
'this demonstration to allow the program to run its course in a short time. To use this
'program for an actual pump test, change the Scan() instruction mSec arguments to Sec. You
'will also need to put a level measurement in the MeasureLevel subroutine.
'A groundwater pump test requires that water level be measured and recorded
'according to the following schedule:
'Minutes into Test
'----------------'
0-10
'
10-30
'
30-100
'
100-300
' 300-1000
'
1000+
Data-Output Interval
-------------------10 seconds
30 seconds
60 seconds
120 seconds
300 seconds
600 seconds
'Declare Variables
Public PTemp
Public Batt_Volt
Public Level
Public LevelMeasureCount As Long
Public ScanCounter(6) As Long
'Declare Data Table
DataTable(LogTable,1,-1)
Minimum(1,Batt_Volt,FP2,0,False)
Sample(1,PTemp,FP2)
Sample(1,Level,FP2)
EndTable
'Declare Level Measurement Subroutine
Sub MeasureLevel
LevelMeasureCount = LevelMeasureCount + 1 'Included to show passes through sub-routine
'Level measurement instructions goes here
EndSub
'Main Program
BeginProg
'Minute 0 to 10 of test: 10-second data-output interval
Scan(10,mSec,0,60) 'There are 60 10-second scans in 10 minutes
ScanCounter(1) = ScanCounter(1) + 1 'Included to show passes through this scan
Battery(Batt_volt)
PanelTemp(PTemp,250)
Call MeasureLevel
'Call Output Tables
CallTable LogTable
NextScan
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Section 7. Installation
'Minute 10 to 30 of test: 30-second data-output interval
Scan(30,mSec,0,40)'There are 40 30-second scans in 20 minutes
ScanCounter(2) = ScanCounter(2) + 1 'Included to show passes through this scan
Battery(Batt_volt)
PanelTemp(PTemp,250)
Call MeasureLevel
'Call Output Tables
CallTable LogTable
NextScan
'Minute 30 to 100 of test: 60-second data-output interval
Scan(60,mSec,0,70)'There are 70 60-second scans in 70 minutes
ScanCounter(3) = ScanCounter(3) + 1 'Included to show passes through this scan
Battery(Batt_volt)
PanelTemp(PTemp,250)
Call MeasureLevel
'Call Output Tables
CallTable LogTable
NextScan
'Minute 100 to 300 of test: 120-second data-output interval
Scan(120,mSec,0,200)'There are 200 120-second scans in 10 minutes
ScanCounter(4) = ScanCounter(4) + 1 'Included to show passes through this scan
Battery(Batt_volt)
PanelTemp(PTemp,250)
Call MeasureLevel
'Call Output Tables
CallTable LogTable
NextScan
'Minute 300 to 1000 of test: 300-second data-output interval
Scan(300,mSec,0,140)'There are 140 300-second scans in 700 minutes
ScanCounter(5) = ScanCounter(5) + 1 'Included to show passes through this scan
Battery(Batt_volt)
PanelTemp(PTemp,250)
Call MeasureLevel
'Call Output Tables
CallTable LogTable
NextScan
'Minute 1000+ of test: 600-second data-output interval
Scan(600,mSec,0,0)'At minute 1000, continue 600-second scans indefinitely
ScanCounter(6) = ScanCounter(6) + 1 'Included to show passes through this scan
Battery(Batt_volt)
PanelTemp(PTemp,250)
Call MeasureLevel
'Call Output Tables
CallTable LogTable
NextScan
EndProg
173
Section 7. Installation
7.9.1.4 Miscellaneous Features
CRBasic example Miscellaneous Features (p. 174) demonstrates use of several
CRBasic features: data type, units, names, event counters, flags, data-output
intervals, and control.
CRBasic Example Ϯϱ.
Miscellaneous Program Features
'This program example demonstrates the use of a single measurement instruction.
'case, the program measures the temperature of the CR1000 wiring panel.
In this
Public RefTemp 'Declare variable to receive instruction
BeginProg
Scan(1,Sec,3,0)
PanelTemp(RefTemp, 250) 'Instruction to make measurement
NextScan
EndProg
'A program can be (and should be!) extensively documented.
'apostrophe is ignored by the CRBasic compiler.
Any text preceded by an
'One thermocouple is measured twice using the wiring panel temperature as the reference
'temperature. The first measurement is reported in Degrees C, the second in Degrees F.
'The first measurement is then converted from Degree C to Degrees F on the subsequent
'line, the result being placed in another variable. The difference between the panel
'reference temperature and the first measurement is calculated, the difference is then
'used to control the status of a program control flag. Program control then
'transitions into device control as the status of the flag is used to determine the
'state of a control port that controls an LED (light emitting diode).
'Battery voltage is measured and stored just because good programming practice dictates
'it be so.
'Two data storage tables are created. Table “OneMin” is an interval driven table that
'stores data every minute as determined by the CR1000 clock. Table “Event” is an event
'driven table that only stores data when certain conditions are met.
'Declare Public (viewable) Variables
Public Batt_Volt As FLOAT
Public PTemp_C
Public AirTemp_C
Public AirTemp_F
Public AirTemp2_F
Public DeltaT_C
Public HowMany
Public Counter As Long
Public SiteName As String * 16
'Declared as Float
'Float by default
'Float by default
'Float by default
'Float by default
'Float by default
'Float by default
'Declared as Long so counter does not have
'rounding error
'Declared as String with 16 chars for a
'site name (optional)
'Declare program control flags & terms. Set the words “High” and “Low” to equal “TRUE”
'and “FALSE” respectively
Public Flag(1) As Boolean
Const High = True
Const Low = False
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Section 7. Installation
'Optional – Declare a Station Name into a location in the Status table.
StationName(CR1000_on_desk)
'Optional -- Declare units.
'data file header.
Units Batt_Volt = Volts
Units PTemp = deg C
Units AirTemp = deg C
Units AirTempF2 = deg F
Units DeltaT_C = deg C
Units are not used in programming, but only appear in the
'Declare an interval driven output table
DataTable(OneMin,True,-1)
DataInterval(0,1,Min,0)
Average(1,AirTemp_C,IEEE4,0)
Maximum(1,AirTemp_C,IEEE4,0,False)
Minimum(1,AirTemp_C,FP2,0,False)
Minimum(1,Batt_Volt,FP2,0,False)
Sample(1,Counter,Long)
Sample(1,SiteName,String)
Sample(1,HowMany, FP2)
'Time driven data storage
'Controls the interval
'Stores temperature average in high
'resolution format
'Stores temperature maximum in high
'resolution format
'Stores temperature minimum in low
'resolution format
'Stores battery voltage minimum in low
'resolution format
'Stores counter in integer format
'Stores site name as a string
'Stores how many data events in low
'resolution format
EndTable
'Declare an event driven data output table
DataTable(Event,True,1000)
DataInterval(0,5,Sec,10)
DataEvent(0,DeltaT_C >= 3,DeltaT_C < 3,0)
Maximum(1,AirTemp_C,FP2,0,False)
Minimum(1,AirTemp_C,FP2,0,False)
Sample(1,DeltaT_C, FP2)
Sample(1,HowMany, FP2)
'Data table – event driven
'—AND interval driven
'—AND event range driven
'Stores temperature maximum in low
'resolution format
'Stores temperature minimum in low
'resolution format
'Stores temp difference sample in low
'resolution format
'Stores how many data events in low
'resolution format
EndTable
BeginProg
'A second way of naming a station is to load the name into a string variable. The is
'place here so it is executed only once, which saves a small amount of program
'execution time.
SiteName = "CR1000SiteName"
175
Section 7. Installation
Scan(1,Sec,1,0)
'Measurements
'Battery Voltage
Battery(Batt_Volt)
'Wiring Panel Temperature
PanelTemp(PTemp_C,_60Hz)
'Type T Thermocouple measurements:
TCDiff(AirTemp_C,1,mV2_5C,1,TypeT,PTemp_C,True,0,_60Hz,1,0)
TCDiff(AirTemp_F,1,mV2_5C,1,TypeT,PTemp_C,True,0,_60Hz,1.8,32)
'Convert from degree C to degree F
AirTemp2_F = AirTemp_C * 1.8 + 32
'Count the number of times through the program.
'Long integer variable in counters.
Counter = Counter + 1
This demonstrates the use of a
'Calculate the difference between air and panel temps
DeltaT_C = AirTemp_C - PTemp_C
'Control the flag based on the difference in temperature.
'set Flag 1 high, otherwise set it low
If DeltaT_C >= 3 Then
Flag(1) = high
Else
Flag(1) = low
EndIf
If DeltaT >= 3 then
'Turn LED connected to Port 1 on when Flag 1 is high
If Flag(1) = high Then
PortSet(1,1)
'alternate syntax:
Else
PortSet(1,0)
'alternate syntax:
EndIf
PortSet(1,high)
PortSet(1,low)
'Count how many times the DataEvent “DeltaT_C>=3” has occurred. The
'TableName.EventCount syntax is used to return the number of data storage events
'that have occurred for an event driven table. This example looks in the data
'table “Event”, which is declared above, and reports the event count. The (1,1)
'after EventCount just needs to be included.
HowMany = Event.EventCount(1,1)
'Call Data Tables
CallTable(OneMin)
CallTable(Event)
NextScan
EndProg
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Section 7. Installation
7.9.1.5 PulseCountReset Instruction
PulseCountReset is used in rare instances to force the reset or zeroing of CR1000
pulse accumulators (see Measurements — Overview (p. 62)).
PulseCountReset is needed in applications wherein two separate PulseCount()
instructions in separate scans measure the same pulse-input terminal. While the
compiler does not allow multiple PulseCount() instructions in the same scan to
measure the same terminal, multiple scans using the same terminal are allowed.
PulseCount() information is not maintained globally, but for each individual
instruction occurrence. So, if a program needs to alternate between fast and slow
scan times, two separate scans can be used with logic to jump between them. If a
PulseCount() is used in both scans, then a PulseCountReset is used prior to
entering each scan.
7.9.1.6 Scaling Array
CRBasic example Scaling Array (p. 177) demonstrates programming to create and
use a scaling array. Several multipliers and offsets are entered at the beginning of
the program and then used by several measurement instructions throughout the
program.
CRBasic Example Ϯ6.
Scaling Array
'This program example demonstrates the use of a scaling array. An array of three
'temperatures are measured. The first is expressed as degrees Celsius, the second as
'Kelvin, and the third as degrees Fahrenheit.
'Declare viewable variables
Public PTemp_C
Public Temp_C(3)
Public Count
'Declare scaling arrays as non-viewable variables
Dim Mult(3)
Dim Offset(3)
'Declare Output Table
DataTable(Min_5,True,-1)
DataInterval(0,5,Min,0)
Average(1,PTemp_C,FP2,0)
Maximum(1,PTemp_C,FP2,0,0)
Minimum(1,PTemp_C,FP2,0,0)
Average(3,Temp_C(),FP2,0)
Minimum(3,Temp_C(1),FP2,0,0)
Maximum(3,Temp_C(1),FP2,0,0)
EndTable
'Begin Program
BeginProg
'Load scaling
Mult(1) = 1.0
Mult(2) = 1.0
Mult(3) = 1.8
array
: Offset(1) = 0
'Scales 1st thermocouple temperature to Celsius
: Offset(2) = 273.15 'Scales 2nd thermocouple temperature to Kelvin
: Offset(3) = 32
'Scales 3rd thermocouple temperature to Fahrenheit
177
Section 7. Installation
Scan(5,Sec,1,0)
'Measure reference temperature
PanelTemp(PTemp_C,_60Hz)
'Measure three thermocouples and scale each. Scaling factors from the scaling array
'are applied to each measurement because the syntax uses an argument of 3 in the Reps
'parameter of the TCDiff() instruction and scaling variable arrays as arguments in the
'Multiplier and Offset parameters.
TCDiff(Temp_C(), 3, mV2_5C,1,TypeT,PTemp_C,True,0,250,Mult(),Offset())
CallTable(Min_5)
NextScan
EndProg
7.9.1.7 Signatures: Example Programs
A program signature is a unique integer calculated from all characters in a given
set of code. When a character changes, the signature changes. Incorporating
signature data into a the CR1000 data set allows system administrators to track
program changes and assure data quality. The following program signatures are
available.
x
x
x
text signature
binary-runtime signature
executable-code signatures
7.9.1.7.1 Text Signature
The text signature is the most-widely used program signature. This signature is
calculated from all text in a program, including blank lines and comments. The
program text signature is found in the Status table as ProgSignature. See
CRBasic example Program Signatures (p. 178).
7.9.1.7.2 Binary Runtime Signature
The binary runtime signature is calculated only from program code. It does not
include comments or blank lines. See CRBasic example Program Signatures (p.
178).
7.9.1.7.3 Executable Code Signatures
Executable code signatures allow signatures to be calculated on discrete sections
of executable code. Executable code is code that resides between BeginProg and
EndProg instructions. See CRBasic example Program Signatures (p. 178).
CRBasic Example Ϯ7.
Program Signatures
'This program example demonstrates how to request the program text signature (ProgSig =
Status.ProgSignature), and the
'binary run-time signature (RunSig = Status.RunSignature). It also calculates two
'executable code segment signatures (ExeSig(1), ExeSig(2))
'Define Public Variables
Public RunSig, ProgSig, ExeSig(2),x,y
178
Section 7. Installation
'Define Data Table
DataTable(Signatures,1,1000)
DataInterval(0,1,Day,10)
Sample(1,ProgSig,FP2)
Sample(1,RunSig,FP2)
Sample(2,ExeSig(),FP2)
EndTable
'Program
BeginProg
ExeSig() = Signature
'initialize executable code signature
'function
Scan(1,Sec,0,0)
ProgSig = Status.ProgSignature
RunSig = Status.RunSignature
x = 24
ExeSig(1) = Signature
'Set variable to Status table entry
'"ProgSignature"
'Set variable to Status table entry
'"RunSignature"
'signature includes code since initial
'Signature instruction
y = 43
ExeSig(2) = Signature
'Signature includes all code since
'ExeSig(1) = Signature
CallTable Signatures
NextScan
7.9.1.8 Use of Multiple Scans
CRBasic example Use of Multiple Scans (p. 179) demonstrates the use of multiple
scans. Some applications require measurements or processing to occur at an
interval different from that of the main program scan. Secondary, or slow
sequence, scans are prefaced with the SlowSequence instruction.
CRBasic Example Ϯ8.
Use of Multiple Scans
'This program example demonstrates the use of multiple scans. Some applications require
'measurements or processing to occur at an interval different from that of the main
'program scan. Secondary scans are preceded with the SlowSequence instruction.
'Declare Public Variables
Public PTemp
Public Counter1
'Declare Data Table 1
DataTable(DataTable1,1,-1)
'DataTable1 is event driven.
'The event is the scan.
Sample(1,PTemp,FP2)
Sample(1, Counter1, fp2)
EndTable
'Main Program
BeginProg
Scan(1,Sec,0,0)
PanelTemp(PTemp,250)
Counter1 = Counter1 + 1
CallTable DataTable1
NextScan
'Begin executable section of program
'Begin main scan
'Call DataTable1
'End main scan
179
Section 7. Installation
SlowSequence
'Begin slow sequence
'Declare Public Variables for Secondary Scan (can be declared at head of program)
Public Batt_Volt
Public Counter2
'Declare Data Table
DataTable(DataTable2,1,-1)
'DataTable2 is event driven.
'The event is the scan.
Sample(1,Batt_Volt,FP2)
Sample(1,Counter2,FP2)
EndTable
Scan(5,Sec,0,0)
Counter2 = Counter2 + 1
Battery(Batt_Volt)
CallTable DataTable2
NextScan
EndProg
7.9.2
'Begin 1st secondary scan
'Call DataTable2
'End slow sequence scan
'End executable section of program
Compiling: Conditional Code
When a CRBasic user program is sent to the CR1000, an exact copy of the
program is saved as a file on the CPU: drive (p. 371). A binary version of the
program, the "operating program", is created by the CR1000 compiler and written
to Operating Memory (p. 372). This is the program version that runs the CR1000.
CRBasic allows definition of conditional code, preceded by a hash character (#),
in the CRBasic program that is compiled into the operating program depending on
the conditional settings. In addition, all Campbell Scientific datalogger (except
the CR200) accept program files, or Include() instruction files, with .DLD
extensions. This feature circumvents system filters that look at file extensions for
specific loggers; it makes possible the writing of a single file of code to run on
multiple models of CRBasic dataloggers.
Note Do not confuse CRBasic files with .DLD extensions with files of .DLD
type used by legacy Campbell Scientific dataloggers.
As an example, pseudo code using this feature might be written as:
#Const Destination = LoggerType
#If Destination = 3000 Then
<code specific to the CR3000>
#ElseIf Destination = 1000 Then
<code specific to the CR1000>
#ElseIf Destination = 800 Then
<code specific to the CR800>
#ElseIf Destination = 6 Then
<code specific to the CR6>
#Else
<code to include otherwise>
#EndIf
This logic allows a simple change of a constant to direct, for instance, which
measurement instructions to include.
CRBasic Editor now features a pre-compile option that enables the creation of a
CRBasic text file with only the desired conditional statements from a larger
master program. This option can also be used at the pre-compiler command line
180
Section 7. Installation
by using -p <outfile name>. This feature allows the smallest size program file
possible to be sent to the CR1000, which may help keep costs down over very
expensive telecommunication links.
CRBasic example Conditional Code (p. 181) shows a sample program that
demonstrates use of conditional compilation features in CRBasic. Within the
program are examples showing the use of the predefined LoggerType constant
and associated predefined datalogger constants (6, 800, 1000, and 3000).
CRBasic Example Ϯ9.
Conditional Code
'This program example demonstrates program compilation than is conditional on datalogger
'model and program speed. Key instructions include #If, #ElseIf, #Else and #EndIf.
'Set program options based on:
' LoggerType, which is a constant predefined in the CR1000 operating system
' ProgramSpeed, which is defined in the following statement:
Const ProgramSpeed = 2
#If ProgramSpeed = 1
Const ScanRate = 1
Const Speed = "1 Second"
#ElseIf ProgramSpeed = 2
Const ScanRate = 10
Const Speed = "10 Second"
'1 second
'10 seconds
#ElseIf ProgramSpeed = 3
Const ScanRate = 30
'30 seconds
Const Speed = "30 Second"
#Else
Const ScanRate = 5
'5 seconds
Const Speed = "5 Second"
#EndIf
'Public Variables
Public ValueRead, SelectedSpeed As String * 50
'Main Program
BeginProg
'Return the selected speed and logger type for display.
#If LoggerType = 3000
SelectedSpeed = "CR3000 running at " & Speed & " intervals."
#ElseIf LoggerType = 1000
SelectedSpeed = "CR1000 running at " & Speed & " intervals."
#ElseIf LoggerType = 800
SelectedSpeed = "CR800 running at " & Speed & " intervals."
#ElseIf LoggerType = 6
SelectedSpeed = "CR6 running at " & Speed & " intervals."
#Else
SelectedSpeed = "Unknown Logger " & Speed & " intervals."
#EndIf
'Open the serial port
SerialOpen(ComC1,9600,10,0,10000)
'Main Scan
Scan(ScanRate,Sec,0,0)
'Measure using different parameters and a different SE channel depending
'on the datalogger type the program is running in.
181
Section 7. Installation
#If LoggerType = 3000
'This instruction is used if the datalogger is a
VoltSe(ValueRead,1,mV1000,22,0,0,_50Hz,0.1,-30)
#ElseIf LoggerType = 1000
'This instruction is used if the datalogger is a
VoltSe(ValueRead,1,mV2500,12,0,0,_50Hz,0.1,-30)
#ElseIf LoggerType = 800
'This instruction is used if the datalogger is a
VoltSe(ValueRead,1,mV2500,3,0,0,_50Hz,0.1,-30)
#ElseIf LoggerType = 6
'This instruction is used if the datalogger is a
VoltSe(ValueRead,1,mV1000,U3,0,0,50,0.1,-30)
#Else
ValueRead = NAN
#EndIf
NextScan
CR3000
CR1000
CR800 Series
CR6 Series
EndProg
7.9.3
Displaying Data: Custom Menus — Details
Related Topics:
‡Custom Menus — Overview (p. 84, p. 581)
‡Data Displays: Custom Menus — Details (p. 182)
‡Custom Menus — Instruction Set (p. 581)
‡Keyboard Display — Overview (p. 83)
‡CRBasic Editor Help for DisplayMenu()
Menus for the CR1000KD Keyboard Display can be customized to simplify
routine operations. Viewing data, toggling control functions, or entering notes are
common applications. Individual menu screens support up to eight lines of text
with up to seven variables.
Use the following CRBasic instructions. Refer to CRBasic Editor Help for
complete information.
DisplayMenu()
Marks the beginning and end of a custom menu. Only one allowed per
program.
Note Label must be at least six characters long to mask default display clock.
EndMenu
Marks the end of a custom menu. Only one allowed per program.
DisplayValue()
Defines a label and displays a value (variable or data table value) not to be
edited, such as a measurement.
MenuItem()
Defines a label and displays a variable to be edited by typing or from a pick
list defined by MenuPick ().
MenuPick()
Creates a pick list from which to edit a MenuItem() variable. Follows
182
Section 7. Installation
immediately after MenuItem(). If variable is declared As Boolean,
MenuPick() allows only True or False or declared equivalents. Otherwise,
many items are allowed in the pick list. Order of items in list is determined by
order of instruction; however, item displayed initially in MenuItem() is
determined by the value of the item.
SubMenu() / EndSubMenu
Defines the beginning and end of a second-level menu.
Note SubMenu() label must be at least six characters long to mask default
display clock.
CRBasic example Custom Menus (p. 185) lists CRBasic programming for a custom
menu that facilitates viewing data, entering notes, and controlling a device.
Following is a list of figures that show the organization of the custom menu that is
programmed using CRBasic example Custom Menus (p. 185).
Custom Menu Example — Home Screen (p. 183)
Custom Menu Example — View Data Window (p. 183)
Custom Menu Example — Make Notes Sub Menu (p. 184)
Custom Menu Example — Predefined Notes Pick List (p. 184)
Custom Menu Example — Free Entry Notes Window (p. 184)
Custom Menu Example — Accept / Clear Notes Window (p. 184)
Custom Menu Example — Control Sub Menu (p. 185)
Custom Menu Example — Control LED Pick List (p. 185)
Custom Menu Example — Control LED Boolean Pick List (p. 185)
Figure 43. Custom Menu Example — Home Screen
Figure 44. Custom Menu Example — View Data Window
183
Section 7. Installation
Figure 45. Custom Menu Example — Make Notes Sub Menu
Figure 46. Custom Menu Example — Predefined Notes Pick List
Figure 47. Custom Menu Example — Free Entry Notes Window
Figure 48. Custom Menu Example — Accept / Clear Notes Window
184
Section 7. Installation
Figure 49. Custom Menu Example — Control Sub Menu
Figure 50. Custom Menu Example — Control LED Pick List
Figure 51. Custom Menu Example — Control LED Boolean Pick List
Note See figures Custom Menu Example — Home Screen (p. 183) through Custom
Menu Example — Control LED Boolean Pick List (p. 185) in reference to the
following CRBasic example Custom Menus (p. 84, p. 581).
CRBasic Example 30.
Custom Menus
'This program example demonstrates the building of a custom CR1000KD Keyboard Display menu.
'Declarations supporting View Data menu item
Public RefTemp
Public TCTemp(2)
'Reference Temp Variable
'Thermocouple Temp Array
'Delarations supporting blank line menu item
Const Escape = "Hit Esc"
'Word indicates action to exit dead end
'Declarations supporting Enter Notes menu item
Public SelectNote As String * 20
'Hold predefined pick list note
185
Section 7. Installation
Const Cal_Done = "Cal Done"
Const Offst_Chgd = "Offset Changed"
Const Blank = ""
Public EnterNote As String * 30
Public CycleNotes As String * 20
Const Accept = "Accept"
Const Clear = "Clear"
'Word stored when Cal_Don selected
'Word stored when Offst_Chgd selected
'Word stored when blank selected
'Variable to hold free entry note
'Variable to hold notes control word
'Notes control word
'Notes control word
'Declarations supporting Control menu item
Const On = true
Const Off = false
Public StartFlag As Boolean
Public CountDown As Long
Public ToggleLED As Boolean
'Assign "On" as Boolean True
'Assign "Off" as Boolean False
'LED Control Process Variable
'LED Count Down Variable
'LED Control Variable
'Define Note DataTable
DataTable(Notes,1,-1)
Sample(1,SelectNote,String)
Sample(1,EnterNote,String)
EndTable
'Set up Notes data table, written
'to when a note is accepted
'Sample Pick List Note
'Sample Free Entry Note
'Define temperature DataTable
DataTable(TempC,1,-1)
DataInterval(0,60,Sec,10)
Sample(1,RefTemp,FP2)
Sample(1,TCTemp(1),FP2)
Sample(1,TCTemp(2),FP2)
EndTable
'Set up temperature data table.
'Written to every 60 seconds with:
'Custom Menu Declarations
DisplayMenu("**CUSTOM MENU DEMO**",-3)
186
'Sample of reference temperature
'Sample of thermocouple 1
'Sample of thermocouple 2
'Create Menu; Upon power up, the custom menu
'is displayed. The system menu is hidden
'from the user.
SubMenu("")
DisplayValue("",Escape)
EndSubMenu
'Dummy Sub menu to write a blank line
'a blank line
'End of dummy submenu
SubMenu("View Data ")
DisplayValue("Ref Temp C",RefTemp)
DisplayValue("TC 1 Temp C",TCTemp(1))
DisplayValue("TC 2 Temp C",TCTemp(2))
EndSubMenu
'Create Submenu named PanelTemps
'Item for Submenu from Public
'Item for Submenu - TCTemps(1)
'Item for Submenu - TCTemps(2)
'End of Submenu
SubMenu("Make Notes ")
MenuItem("Predefined",SelectNote)
MenuPick(Cal_Done,Offset_Changed)
MenuItem("Free Entry",EnterNote)
MenuItem("Accept/Clear",CycleNotes)
MenuPick(Accept,Clear)
EndSubMenu
'Create Submenu named PanelTemps
'Choose predefined notes Menu Item
'Create pick list of predefined notes
'User entered notes Menu Item
Section 7. Installation
SubMenu("Control ")
MenuItem("Count to LED",CountDown)
MenuPick(15,30,45,60)
MenuItem("Manual LED",toggleLED)
MenuPick(On,Off)
EndSubMenu
EndMenu
'Create
'Create
'Create
'Manual
Submenu named PanelTemps
menu item CountDown
a pick list for CountDown
LED control Menu Item
'End custom menu creation
'Main Program
BeginProg
CycleNotes = "??????"
'Initialize Notes Sub Menu,
'write ????? as a null
Scan(1,Sec,3,0)
'Measurements
PanelTemp(RefTemp,250)
'Measure Reference Temperature
'Measure Two Thermocouples
TCDiff(TCTemp(),2,mV2_5C,1,TypeT,RefTemp,True,0,_60Hz,1.0,0)
CallTable TempC
'Call data table
'Menu Item "Make Notes" Support Code
If CycleNotes = "Accept" Then
CallTable Notes
CycleNotes = "Accepted"
Delay(1,500,mSec)
SelectNote = ""
EnterNote = ""
CycleNotes = "??????"
EndIf
If CycleNotes = "Clear" Then
SelectNote = ""
EnterNote = ""
CycleNotes = "??????"
EndIf
'Write
'Write
'Pause
'Clear
'Clear
'Write
data to Notes data table
"Accepted" after written
so user can read "Accepted"
pick list note
free entry note
????? as a null prompt
'Clear
'Clear
'Clear
'Write
notes when requested
pick list note
free entry note
????? as a null prompt
'Menu Item "Control" Menu Support Code
CountDown = CountDown - 1
'Count down by 1
If CountDown <= 0
'Stop count down from passing 0
CountDown = 0
EndIf
If CountDown > 0 Then
StartFlag = True
'Indicate countdown started
EndIf
If StartFlag = True AND CountDown = 0 Then'Interprocess count down
'and manual LED
ToggleLED = True
StartFlag = False
EndIf
If StartFlag = True AND CountDown <> 0 Then'Interprocess count down and manual LED
ToggleLED = False
EndIf
PortSet(4,ToggleLED)
'Set control port according
'to result of processing
NextScan
EndProg
187
Section 7. Installation
7.9.4
Data Input: Loading Large Data Sets
Large data sets, such as look up tables or tag numbers, can be loaded in the
CR1000 for use by the CRBasic program. This is efficiently accomplished by
using the Data, DataLong, and Read instructions, as demonstrated in CRBasic
example Loading Large Data Sets (p. 188).
CRBasic Example 31.
Loading Large Data Sets
'This program example demonstrates how to load a set of data into variables. Twenty values
'are loaded into two arrays: one declared As Float, one declared As Long. Individual Data
'lines can be many more values long than shown (limited only by maximum statement length),
'and many more lines can be written. Thousands of values can be loaded in this way.
'Declare Float and Long variables.
Public DataSetFloat(10) As Float
Public DataSetLong(10) As Long
Dim x
Can also be declared as Dim.
'Write data set to CR1000 memory
Data 1.1,2.2,3.3,4.4,5.5
Data -1.1,-2.2,-3.3,-4.4,-5.5
DataLong 1,2,3,4,5
DataLong -1,-2,-3,-4,-5
'Declare data table
DataTable (DataSet_,True,-1)
Sample (10,DataSetFloat(),Float)
Sample (10,DataSetLong(),Long)
EndTable
BeginProg
'Assign Float data to variable array declared As Float
For x = 1 To 10
Read DataSetFloat(x)
Next x
'Assign Long data to variable array declared As Long
For x = 1 To 10
Read DataSetLong(x)
Next x
Scan(1,sec,0,1)
'Write all data to final-data memory
CallTable DataSet_
NextScan
EndProg
7.9.5
Data Input: Array-Assigned Expression
CRBasic provides for the following operations on one dimension of a multidimensional array:
188
Section 7. Installation
x
x
x
x
x
Initialize
Transpose
Copy
Mathematical
Logical
Examples include:
x
x
x
x
Process a variable array without use of For/Next
Create boolean arrays based on comparisons with another array or a scalar
variable
Copy a dimension to a new location
Perform logical operations for each element in a dimension using scalar or
similarly located elements in different arrays and dimensions
Note Array-assigned expression notation is an alternative to For/Next
instructions, typically for use by more advanced programmers. It will probably
not reduce processing time significantly over the use of For/Next. To reduce
processing time, consider using the Move() instruction, which requires more
intensive programming.
Syntax rules:
x
Definitions:
o
o
x
x
x
x
An empty set of parentheses designates an array-assigned expression. For
example, reference array() or array(a,b,c)().
Only one dimension of the array is operated on at a time.
To select the dimension to be operated on, negate the dimension of index of
interest.
Operations will not cross dimensions. An operation begins at the specified
starting point and continues to one of the following:
o
o
o
x
x
x
Least-significant dimension — the last or right-most figure in an array
index. For example, in the array array(a,b), b is the least-significant
dimension index. In the array array(a,b,c), c is least significant.
Negate — place a negative or minus sign (-) before the array index. For
example, when negating the least-significant dimension in array(a,b,c),
the notion is array(a,b,-c)
End of the dimension
Where the dimension is specified by a negative
Where the dimension is the least significant (default)
If indices are not specified, or none have been preceded with a minus sign,
the least significant dimension of the array is assumed.
The offset into the dimension being accessed is given by (a,b,c).
If the array is referenced as array(), the starting point is array(1,1,1) and the
least significant dimension is accessed. For example, if the array is declared
as test(a,b,c), and subsequently referenced as test(), then the starting point is
test(1,1,1) and dimension c is accessed.
189
Section 7. Installation
Table 24. CRBasic Example. Array Assigned Expression: Sum Columns and Rows
'This example sums three rows and two columns of a 3x2 array.
'Source array image:
'1.23,2.34
'3.45,4.56
'5.67,6.78
Public Array(3,2) = {1.23,2.34,3.45,4.56,5.67,6.78}'load values into source array
Public RowSum(3)
Public ColumnSum(2)
BeginProg
Scan(1,Sec,0,0)
'For each row, add up the two columns
RowSum() = Array(-1,1)() + Array(-1,2)()
'For each column, add up the three rows
ColumnSum() = Array(1,-1)() + Array(2,-1)() + Array(3,-1)()
NextScan
EndProg
Table 25. CRBasic Example. Array Assigned Expression: Transpose an Array
'This example transposes a 3x2 array to a 2x3 array
'Source array image:
'1,2
'3,4
'5,6
'Destination array image (transpose of source):
'1,3,5
'2,4,6
'Dimension and initialize source array
Public A(3,2) = {1,2,3,4,5,6}
'Dimension destination array
Public At(2,3)
'Delcare For/Next counter
Dim i
BeginProg
Scan (1,Sec,0,0)
For i = 1 To 2
'For each column of the source array A(), copy the column into a row of the
'destination array At()
At(i,-1)() = A(-1,i)()
Next i
NextScan
EndProg
190
Section 7. Installation
Table 26. CRBasic Example. Array Assigned Expression: Comparison / Boolean Evaluation
'Example: Comparison / Boolean Evaluation
'Element-wise comparisons is performed through scalar expansion or by comparing each
'element in one array to a similarly located element in another array to generate a
'resultant boolean array to be used for decision making and control, such as
'an array input to a SDM-CD16AC.
Public
Public
Public
Public
Public
Public
TempC(3) = {15.1234,20.5678,25.9876}
TempC_Rounded(3)
TempDiff(3)
TempC_Alarm(3) As Boolean
TempF_Thresh(3) = {55,60,80}
TempF_Alarm(3) As Boolean
BeginProg
Scan(1,Sec,0,0)
'element-wise comparison of each temperature in the array to a scalar value
'set corresponding alarm boolean value true if temperature exceeds 20 degC
TempC_Alarm() = TempC() > 20
'some, not all or most, instructions will accept this array notation to auto-index
'through the array
'round each temperature to the nearest tenth of a degree
TempC_Rounded() = Round(TempC(),1)
'element-wise subtraction
'each element in TempC_Rounded is subtracted from the similarly located element inTempC
'calculate the difference between each TempC value and the rounded counterpart
TempDiff() = TempC() - TempC_Rounded()
'element-wise operations can be mixed with scalar expansion operations
'set corresponding alarm boolean value true if temperature, after being
'converted to degF, exceeds it's corresponding alarm threshold value in degF
TempF_Alarm() = (TempC() * 1.8 + 32) > TempF_Thresh()
NextScan
EndProg
191
Section 7. Installation
Table 27. CRBasic Example. Array Assigned Expression: Fill Array Dimension
'Example: Fill Array Dimension
Public
Public
Public
Public
Public
Public
Public
A(3)
B(3,2)
C(4,3,2)
Da(3,2) = {1,1,1,1,1,1}
Db(3,2)
DMultiplier(3) = {10,100,1000}
DOffset(3) = {1,2,3}
BeginProg
Scan(1,Sec,0,0)
A() = 1 'set all elements of 1D array or first dimension to 1
B(1,1)() = 100 'set B(1,1) and B(1,2) to 100
B(-2,1)() = 200 'set B(2,1) and B(3,1) to 200
B(-2,2)() = 300 'set B(2,2) and B(3,2) to 300
C(1,-1,1)() = A() 'copy A(1), A(2), and A(3) into C(1,1,1), C(1,2,1), and C(1,3,1),
'respectively
C(2,-1,1)() = A() * 1.8 + 32 'scale and then copy A(1), A(2), and A(3) into C(2,1,1),
'C(2,2,1), and C(2,3,1), respectively
'scale the first column of Da by corresponding multiplier and offset
'copy the result into the first column of Db
'then set second column of Db to NAN
Db(-1,1)() = Da(-1,1)() * DMultiplier() + DOffset()
Db(-1,2)() = NAN
NextScan
EndProg
7.9.6
Data Output: Calculating Running Average
The AvgRun() instruction calculates a running average of a measurement or
calculated value. A running average (Dest) is the average of the last N values
where N is the number of values, as expressed in the running-average equation:
where XN is the most recent value of the source variable and XN-1 is the previous
value (X1 is the oldest value included in the average, i.e., N-1 values back from
the most recent). NANs are ignored in the processing of AvgRun() unless all
values in the population are NAN.
AvgRun() uses high-precision math, so a 32-bit extension of the mantissa is saved
and used internally resulting in 56 bits of precision.
Note This instruction should not normally be inserted within a For/Next
construct with the Source and Destination parameters indexed and Reps set to 1.
Doing so will perform a single running average, using the values of the different
192
Section 7. Installation
elements of the array, instead of performing an independent running average on
each element of the array. The results will be a running average of a spatial
average of the various source array elements.
A running average is a digital low-pass filter; its output is attenuated as a function
of frequency, and its output is delayed in time. Degree of attenuation and phase
shift (time delay) depend on the frequency of the input signal and the time length
(which is related to the number of points) of the running average.
The figure Running-Average Frequency Response (p. 194) is a graph of signal
attenuation plotted against signal frequency normalized to 1/(running average
duration). The signal is attenuated by a synchronizing filter with an order of 1
(simple averaJLQJ6LQʌ;ʌ;ZKHUH;LVWKHUDWLRRIWKHLQSXWVLJQDO
frequency to the running-average frequency (running-average frequency = 1 /
time length of the running average).
Example:
Scan period = 1 ms,
N value = 4 (number of points to average),
Running-average duration = 4 ms
Running-average frequency = 1 / (running-average duration = 250 Hz)
Input-signal frequency = 100 Hz
Input frequency to running average (normalized frequency) = 100 / 250 = 0.4
6LQʌʌ RUUHDGIURPILJXUHRunning-Average Frequency
Response (p. 194), where the X axis is 0.4)
For a 100 Hz input signal with an amplitude of 10 V peak-to-peak, a running
average outputs a 100 Hz signal with an amplitude of 7.57 V peak-to-peak.
There is also a phase shift, or delay, in the AvgRun() output. The formula for
calculating the delay, in number of samples, is:
Delay in samples = (N–1) / 2
Note N = number of points in running average
To calculate the delay in time, multiply the result from the above equation by the
period at which the running average is executed (usually the scan period):
'HOD\LQWLPH VFDQSHULRG‡1–1) / 2
For the example above, the delay is:
'HOD\LQWLPH PV‡– 1) / 2 = 1.5 ms
Example:
An accelerometer was tested while mounted on a beam. The test had the
following characteristics:
o
o
o
$FFHOHURPHWHUUHVRQDQWIUHTXHQF\§+]
Measurement period = 2 ms
Running average duration = 20 ms (frequency of 50 Hz)
Normalized resonant frequency was calculated as follows:
193
Section 7. Installation
36 Hz / 50 Hz = 0.72
SIN(0.72›) / (0.72›) = 0.34.
So, the recorded amplitude was about 1/3 of the input-signal amplitude. A
CRBasic program was written with variables Accel2 and Accel2RA. The
raw measurement was stored in Accel2. Accel2RA held the result of
performing a running average on the Accel2. Both values were stored at a
rate of 500 Hz. Figure Running-Average Signal Attenuation (p. 195) shows the
two variables plotted to illustrate the attenuation. The running-average value
has the lower amplitude.
The resultant delay, Dr, is calculated as follows:
Dr = (scan rate) ‡ (N–1)/2 = 2 ms (10–1)/2
= 9 ms
Dr is about 1/3 of the input-signal period.
Figure 52. Running-Average Frequency Response
194
Section 7. Installation
Figure 53. Running-Average Signal Attenuation
7.9.7
Data Output: Triggers and Omitting Samples
TrigVar is the third parameter in the DataTable() instruction. It controls whether
or not a data record is written to final memory. TrigVar control is subject to other
conditional instructions such as the DataInterval() and DataEvent() instructions.
DisableVar is the last parameter in most output processing instructions, such as
Average(), Maximum(), Minimum(), etc. It controls whether or not a particular
measurement or value is included in the affected output-processing function.
For individual measurements to affect summary data, output processing
instructions such as Average() must be executed whenever the data table is called
from the program — normally once each scan. For example, for an average to be
calculated for the hour, each measurement must be added to a total over the hour.
This accumulation of data is not affected by TrigVar. TrigVar controls only the
moment when the final calculation is performed and the processed data (the
average) are written to the data table. For this summary moment to occur,
TrigVar and all other conditions (such as DataInterval() and DataEvent()) must
be true. Expressed another way, when TrigVar is false, output processing
instructions (for example, Average()) perform intermediate processing but not the
final process, and a new record will not be created.
Note In many applications, output records are solely interval based and TrigVar
is always set to TRUE (-1). In such applications, DataInterval() is the sole
specifier of the output trigger condition.
Figure Data from TrigVar Program (p. 196) shows data produced by CRBasic
example Using TrigVar to Trigger Data Storage (p. 196), which uses TrigVar rather
than DataInterval() to trigger data storage.
195
Section 7. Installation
Figure 54. Data from TrigVar Program
CRBasic Example 3Ϯ.
Using TrigVar to Trigger Data Storage
'This program example demonstrates the use of the TrigVar parameter in the DataTable()
'instruction to trigger data storage. In this example, the variable Counter is
'incremented by 1 at each scan. The data table, which includes the Sample(), Average(), and
'Totalize() instructions, is called every scan. Data are stored when TrigVar is true, and
'TrigVar is True when Counter = 2 or Counter = 3. Data stored are the sample, average,
'and total of the variable Counter, which is equal to 0, 1, 2, 3, or 4 when the data table
'is called.
Public Counter
DataTable(Test,Counter=2 or Counter=3,100)
Sample(1,Counter,FP2)
Average(1,Counter,FP2,False)
Totalize(1,Counter,FP2,False)
EndTable
BeginProg
Scan(1,Sec,0,0)
Counter = Counter + 1
If Counter = 5 Then
Counter = 0
EndIf
CallTable Test
NextScan
EndProg
196
Section 7. Installation
7.9.8
Data Output: Two Intervals in One Data Table
CRBasic Example 33.
Two Data-Output Intervals in One Data Table
'This program example demonstrates the use of two time intervals in a data table. One time
'interval in a data table is the norm, but some applications require two.
'
'A table with two time intervals should be allocated memory as is done with a conditional table:
'rather than auto-allocate, set a fixed number of records.
'Declare Public Variables
Public PTemp, batt_volt, airtempC, deltaT
Public int_fast As Boolean
Public int_slow As Boolean
Public counter(4) As Long
'Declare Data Table
'
'Table is output on one of two intervals, depending on condition.
'Note the parenthesis around the TriggerVariable AND statements.
DataTable(TwoInt,(int_fast AND TimeIntoInterval(0,5,Sec)) OR (int_slow AND _
TimeIntoInterval(0,15,sec)),-1)
Minimum(1,batt_volt,FP2,0,False)
Sample(1,PTemp,FP2)
Maximum(1,counter(1),Long,False,False)
Minimum(1,counter(1),Long,False,False)
Maximum(1,deltaT,FP2,False,False)
Minimum(1,deltaT,FP2,False,False)
Average(1,deltaT,IEEE4,false)
EndTable
'Main Program
BeginProg
Scan(1,Sec,0,0)
PanelTemp(PTemp,250)
Battery(Batt_volt)
counter(1) = counter(1) + 1
'Measure thermocouple
TCDiff(AirTempC,1,mV2_5C,1,TypeT,PTemp,True,0,250,1.0,0)
'calculate the difference in air temperature and panel temperature
deltaT = airtempC - PTemp
'When the difference in air temperatures is >=3 turn LED on and trigger the faster of
'the two data-table intervals.
If deltaT >= 3 Then
PortSet(4,true)
int_fast = true
int_slow = false
Else
PortSet(4,false)
int_fast = false
int_slow = true
EndIf
197
Section 7. Installation
'Call output tables
CallTable TwoInt
NextScan
EndProg
7.9.9
Data Output: Using Data Type Bool8
Variables used exclusively to store either True or False are usually declared As
BOOLEAN. When recorded in final-data memory, the state of Boolean variables
is typically stored in BOOLEAN data type. BOOLEAN data type uses a fourbyte integer format. To conserve final-data memory or telecommunication band,
you can use the BOOL8 data type. A BOOL8 is a one-byte value that holds eight
bits of information (eight states with one bit per state). To store the same
information using a 32 bit BOOLEAN data type, 256 bits are required (8 states *
32 bits per state).
When programming with BOOL8 data type, repetitions in the output processing
DataTable() instruction must be divisible by two, since an odd number of bytes
cannot be stored. Also note that when the CR1000 converts a LONG or FLOAT
data type to BOOL8, only the least significant eight bits of the binary equivalent
are used, i.e., only the binary representation of the decimal integer modulo divide
(p. 520) 256 is used.
Example:
Given: LONG integer 5435
Find: BOOL8 representation of 5435
Solution:
5435 / 256 = 21.2304687
0.2304687 * 256 = 59
Binary representation of 59 = 00111011 (CR1000 stores
these bits in reverse order)
When datalogger support software (p. 95) retrieves the BOOL8 value, it splits it
apart into eight fields of -1 or 0 when storing to an ASCII file. Consequently,
more memory is required for the ASCII file, but CR1000 memory is conserved.
The compact BOOL8 data type also uses less telecommunication band width
when transmitted.
CRBasic example Programming with Bool8 and Bit-Shift Operators (p. 200)
programs the CR1000 to monitor the state of 32 "alarms" as a tutorial exercise.
The alarms are toggled by manually entering zero or non-zero (e.g., 0 or 1) in
each public variable representing an alarm as shown in figure Alarms Toggled in
Bit-Shift Example (p. 199). Samples of the four public variables FlagsBool8(1),
FlagsBool8(2), FlagsBool8(3), and FlagsBool8(4) are stored in data table
Bool8Data as four one-byte values. However, as shown in figure Bool8 Data
from Bit-Shift Example (Numeric Monitor) (p. 199), when viewing the data table in a
numeric monitor (p. 521), data are conveniently translated into 32 values of True or
False. In addition, as shown in figure Bool8 Data from Bit-Shift Example (PC
Data File) (p. 200), when datalogger support software (p. 95) stores the data in an
ASCII file, it is stored as 32 columns of either -1 or 0, each column representing
the state of an alarm. You can use variable aliasing (p. 138) in the CRBasic
program to make the data more understandable.
198
Section 7. Installation
Figure 55. Alarms Toggled in Bit-Shift Example
Figure 56. Bool8 Data from Bit-Shift Example (Numeric Monitor)
199
Section 7. Installation
Figure 57. Bool8 Data from Bit-Shift Example (PC Data File)
CRBasic Example 34.
Programming with Bool8 and a Bit-Shift Operator
'This program example demonstrates the use of the Bool8 data type and the ">>" bit-shift
'operator.
Public Alarm(32)
Public Flags As Long
Public FlagsBool8(4) As Long
DataTable(Bool8Data,True,-1)
DataInterval(0,1,Sec,10)
'store bits 1 through 16 in columns 1 through 16 of data file
Sample(2,FlagsBool8(1),Bool8)
'store bits 17 through 32 in columns 17 through 32 of data file
Sample(2,FlagsBool8(3),Bool8)
EndTable
BeginProg
Scan(1,Sec,3,0)
'Reset all bits each pass before setting bits selectively
Flags = &h0
'Set bits selectively. Hex is used to save space.
'Logical OR bitwise comparison
200
Section 7. Installation
'If bit in
'Flags Is
'---------'
0
'
0
'
1
'
1
OR bit in
Bin/Hex Is
---------0
1
0
1
The result
Is
---------0
1
1
1
'Binary equivalent of Hex:
If Alarm(1) Then Flags = Flags OR &h1
If Alarm(2) Then Flags = Flags OR &h2
If Alarm(3) Then Flags = Flags OR &h4
If Alarm(4) Then Flags = Flags OR &h8
If Alarm(5) Then Flags = Flags OR &h10
If Alarm(6) Then Flags = Flags OR &h20
If Alarm(7) Then Flags = Flags OR &h40
If Alarm(8) Then Flags = Flags OR &h80
If Alarm(9) Then Flags = Flags OR &h100
If Alarm(10) Then Flags = Flags OR &h200
If Alarm(11) Then Flags = Flags OR &h400
If Alarm(12) Then Flags = Flags OR &h800
If Alarm(13) Then Flags = Flags OR &h1000
If Alarm(14) Then Flags = Flags OR &h2000
If Alarm(15) Then Flags = Flags OR &h4000
If Alarm(16) Then Flags = Flags OR &h8000
If Alarm(17) Then Flags = Flags OR &h10000
If Alarm(18) Then Flags = Flags OR &h20000
If Alarm(19) Then Flags = Flags OR &h40000
If Alarm(20) Then Flags = Flags OR &h80000
If Alarm(21) Then Flags = Flags OR &h100000
If Alarm(22) Then Flags = Flags OR &h200000
If Alarm(23) Then Flags = Flags OR &h400000
If Alarm(24) Then Flags = Flags OR &h800000
If Alarm(25) Then Flags = Flags OR &h1000000
If Alarm(26) Then Flags = Flags OR &h2000000
If Alarm(27) Then Flags = Flags OR &h4000000
If Alarm(28) Then Flags = Flags OR &h8000000
If Alarm(29) Then Flags = Flags OR &h10000000
If Alarm(30) Then Flags = Flags OR &h20000000
If Alarm(31) Then Flags = Flags OR &h40000000
If Alarm(32) Then Flags = Flags OR &h80000000
'
&b1
'
&b10
'
&b100
'
&b1000
'
&b10000
'
&b100000
'
&b1000000
'
&b10000000
'
&b100000000
'
&b1000000000
'
&b10000000000
'
&b100000000000
'
&b1000000000000
'
&b10000000000000
'
&b100000000000000
'
&b1000000000000000
'
&b10000000000000000
'
&b100000000000000000
'
&b1000000000000000000
'
&b10000000000000000000
'
&b100000000000000000000
'
&b1000000000000000000000
'
&b10000000000000000000000
'
&b100000000000000000000000
'
&b1000000000000000000000000
'
&b10000000000000000000000000
'
&b100000000000000000000000000
'
&b1000000000000000000000000000
'
&b10000000000000000000000000000
' &b100000000000000000000000000000
' &b1000000000000000000000000000000
'&b10000000000000000000000000000000
'Note &HFF = &B11111111. By shifting at 8 bit increments along 32-bit 'Flags' (Long
'data type), the first 8 bits in the four Longs FlagsBool8(4) are loaded with alarm
'states. Only the first 8 bits of each Long 'FlagsBool8' are stored when converted
'to Bool8.
'Logical AND bitwise comparison
'If bit in
'Flags Is
'---------'
0
'
0
'
1
'
1
OR bit in
Bin/Hex Is
---------0
1
0
1
The result
Is
---------0
0
0
1
201
Section 7. Installation
FlagsBool8(1)
FlagsBool8(2)
FlagsBool8(3)
FlagsBool8(4)
=
=
=
=
Flags AND
(Flags >>
(Flags >>
(Flags >>
&HFF
8) AND &HFF
16) AND &HFF
24) AND &HFF
'AND
'AND
'AND
'AND
1st
2nd
3rd
4th
8
8
8
8
bits
bits
bits
bits
of
of
of
of
"Flags"
"Flags"
"Flags"
"Flags"
&
&
&
&
11111111
11111111
11111111
11111111
CallTable(Bool8Data)
NextScan
EndProg
7.9.10 Data Output: Using Data Type NSEC
Data of NSEC type reside only in final-data memory. A datum of NSEC consists
of eight bytes — four bytes of seconds since 1990 and four bytes of nanoseconds
into the second. Nsec is declared in the Data Type parameter in final-data
memory output-processing instructions (p. 542). It is used in the following
applications:
x
x
x
Placing a time stamp in a second position in a record.
Accessing a time stamp from a data table and subsequently storing it as part
of a larger data table. Maximum(), Minimum(), and FileTime() instructions
produce a time stamp that may be accessed from the program after being
written to a data table. The time of other events, such as alarms, can be stored
using the RealTime() instruction.
Accessing and storing a time stamp from another datalogger in a PakBus
network.
7.9.10.1 NSEC Options
NSEC is used in a CRBasic program one of the following ways. In all cases, the
time variable is only sampled with a Sample() instruction, Reps = 1.
1. Time variable is declared As Long. Sample() instruction assumes the time
variable holds seconds since 1990 and microseconds into the second is 0. The
value stored in final-data memory is a standard time stamp. See CRBasic
example NSEC — One Element Time Array (p. 202).
2. Time-variable array dimensioned to (2) and As Long — Sample() instruction
assumes the first time variable array element holds seconds since 1990 and the
second element holds microseconds into the second. See CRBasic example
NSEC — Two Element Time Array (p. 203).
3. Time-variable array dimensioned to (7) or (9) and As Long or As Float —
Sample() instruction assumes data are stored in the variable array in the
sequence year, month, day of year, hour, minutes, seconds, and milliseconds.
See CRBasic example NSEC — Seven and Nine Element Time Arrays (p. 204).
CRBasic example NSEC — Convert Time Stamp to Universal Time (p. 202) shows
one of several practical uses of the NSEC data type.
202
Section 7. Installation
CRBasic Example 3ϱ.
NSEC — One Element Time Array
'This program example demonstrates the use of NSEC data type to determine seconds since
'00:00:00 1 January 1990. A time stamp is retrieved into variable TimeVar(1) as seconds
'since 00:00:00 1 January 1990. Because the variable is dimensioned to 1, NSEC assumes
'the value = seconds since 00:00:00 1 January 1990.
'Declarations
Public PTemp
Public TimeVar(1) As Long
DataTable(FirstTable,True,-1)
DataInterval(0,1,Sec,10)
Sample(1,PTemp,FP2)
EndTable
DataTable(SecondTable,True,-1)
DataInterval(0,5,Sec,10)
Sample(1,TimeVar,Nsec)
EndTable
'Program
BeginProg
Scan(1,Sec,0,0)
TimeVar = FirstTable.TimeStamp
CallTable FirstTable
CallTable SecondTable
NextScan
EndProg
CRBasic Example 36.
NSEC — Two Element Time Array
'This program example demonstrates how to determine seconds since 00:00:00 1 January 1990,
'and microseconds into the last second. This is done by retrieving variable TimeStamp into
'variables TimeOfMaxVar(1) and TimeOfMaxVar(2). Because the variable TimeOfMaxVar() is
'dimensioned to 2, NSEC assumes the following:
' 1) TimeOfMaxVar(1) = seconds since 00:00:00 1 January 1990, and
' 2) TimeOfMaxVar(2) = microseconds into a second.
'Declarations
Public PTempC
Public MaxVar
Public TimeOfMaxVar(2) As Long
DataTable(FirstTable,True,-1)
DataInterval(0,1,Min,10)
Maximum(1,PTempC,FP2,False,True)
EndTable
DataTable(SecondTable,True,-1)
DataInterval(0,5,Min,10)
Sample(1,MaxVar,FP2)
Sample(1,TimeOfMaxVar,Nsec)
EndTable
203
Section 7. Installation
'Program
BeginProg
Scan(1,Sec,0,0)
PanelTemp(PTempC,250)
MaxVar = FirstTable.PTempC_Max
TimeOfMaxVar = FirstTable.PTempC_TMx
CallTable FirstTable
CallTable SecondTable
NextScan
EndProg
CRBasic Example 37.
NSEC — Seven and Nine Element Time Arrays
'This program example demonstrates the use of NSEC data type to sample a time stamp into
'final-data memory using an array dimensioned to 7 or 9.
'A time stamp is retrieved into variable rTime(1) through rTime(9) as year, month, day,
'hour, minutes, seconds, and microseconds using the RealTime() instruction. The first
'seven time values are copied to variable rTime2(1) through rTime2(7). Because the
'variables are dimensioned to 7 or greater, NSEC assumes the first seven time factors
'in the arrays are year, month, day, hour, minutes, seconds, and microseconds.
'Declarations
Public rTime(9) As Long
Public rTime2(7) As Long
Dim x
DataTable(SecondTable,True,-1)
DataInterval(0,5,Sec,10)
Sample(1,rTime,NSEC)
Sample(1,rTime2,NSEC)
EndTable
'Program
BeginProg
Scan(1,Sec,0,0)
RealTime(rTime)
For x = 1 To 7
rTime2(x) = rTime(x)
Next
CallTable SecondTable
NextScan
EndProg
204
'(or Float)
'(or Float)
Section 7. Installation
CRBasic Example 38.
NSEC —Convert Timestamp to Universal Time
'This program example demonstrates the use of NSEC data type to convert a data time stamp
'to universal time.
'
'Application: the CR1000 needs to display Universal Time (UT) in human readable
'string forms. The CR1000 can calculate UT by adding the appropriate offset to a
'standard time stamp. Adding offsets requires the time stamp be converted to numeric
'form, the offset applied, then the new time be converted back to string forms.
'These are accomplished by:
' 1) reading Public.TimeStamp into a LONG numeric variable.
' 2) store it into a type NSEC datum in final-data memory.
' 3) sample it back into string form using the TableName.FieldName notation.
'Declarations
Public UTTime(3) As String * 30
Dim TimeLong As Long
Const UTC_Offset = -7 * 3600
'-7 hours offset (as seconds)
DataTable(TimeTable,true,1)
Sample(1,TimeLong,Nsec)
EndTable
'Program
BeginProg
Scan(1,Sec,0,0)
'1) Read Public.TimeStamp into a LONG numeric variable. Note that TimeStamp is a
'
system variable, so it is not declared.
TimeLong = Public.TimeStamp(1,1) + UTC_Offset
'2) Store it into a type NSEC datum in final-data memory.
CallTable(TimeTable)
'3) sample time to three string forms using the TableName.FieldName notation.
'Form 1: "mm/dd/yyyy hr:mm:ss
UTTime(1) = TimeTable.TimeLong(1,1)
'Form 2: "dd/mm/yyyy hr:mm:ss
UTTime(2) = TimeTable.TimeLong(3,1)
'Form 3: "ccyy-mm-dd hr:mm:ss (ISO 8601 Int'l Date)
UTTime(3) = TimeTable.TimeLong(4,1)
NextScan
EndProg
7.9.11 Data Output: Writing High-Frequency Data to Memory
Cards
Related Topics:
‡Memory Card (CRD: Drive) — Overview (p. 89)
‡Memory Card (CRD: Drive) — Details (p. 376)
‡Memory Cards and Record Numbers (p. 466)
‡Data Output: Writing High-Frequency Data to Memory Cards (p. 205)
‡File-System Errors (p. 389)
‡Data Storage Devices — List (p. 653)
205
Section 7. Installation
‡Data-File Format Examples (p. 379)
‡Data Storage Drives Table (p. 373)
The best method for writing high-frequency time-series data to memory cards,
especially in high-speed measurement applications, is usually to use the
TableFile() instruction with Option 64. It supports 16 GB or smaller memory
cards and permits smaller and variable file sizes.
7.9.11.1 TableFile() with Option 64
Option 64 has been added as a format option for the CRBasic instruction
TableFile(). It combines the speed and efficiency of the CardOut() instruction
with the flexibility of the TableFile() instruction. Memory cards1 up to 16 GB are
supported. TableFile() is a CRBasic instruction that creates a file from a data
table in datalogger CPU memory. Option 64 directs that the file be written in
TOB3 format exclusively to the CRD: drive2.
Syntax for the TableFile() instruction is as follows:
TableFile(FileName, Option, MaxFiles, NumRecs/
TimeIntoInterval, Interval, Units, OutStat, LastFileName)
where Option is given the argument of 64. Refer to CRBasic Editor Help3 for a
detailed description of each parameter.
Note The CRD: drive (the drive designation for the optional memory card) is the
only drive that is allowed for use with Option 64.
Note Memory cards add a measure of security in guarding against data loss.
However, no system is infallible. Finding a functioning memory card in the mud
after a moose has trampled your weather station or a tractor has run an offset disk
over your soil-moisture station may be difficult. The best rule is to collect data
from the CR1000 only as often as you can afford to lose the data. In other words,
if you can afford to lose a months worth of data, you can afford to collect the data
only once a month.
1
Memory cards for the CR1000 are the compact flash (CF) type.
2
The CRD: drive is a memory drive created when a memory card is connected into the CR1000
through the appropriate peripheral device. The CR1000 is adapted for CF use by addition of the
NL115 or CFM100 modules. NL115 and CFM100 modules are available at additional cost from
Campbell Scientific.
3
CRBasic Editor is included in Campbell Scientific datalogger support software (p. 95) suites
LoggerNet, PC400, and RTDAQ.
7.9.11.2 TableFile() with Option 64 Replaces CardOut()
TableFile() with Option 64 has several advantages over CardOut() when used in
most applications. These include:
x
x
206
Allowing multiple small files to be written from the same data table so that
storage for a single table can exceed 2 GB. TableFile() controls the size of
its output files through the NumRecs, TimeIntoInterval, and Interval
parameters.
Faster compile times when small file sizes are specified.
Section 7. Installation
x
Easy retrieval of closed files with File Control (p. 515) utility, FTP, or e-mail.
7.9.11.3 TableFile() with Option 64 Programming
As shown in the following CRBasic code snip, the TableFile() instruction must
be placed inside a DataTable() / EndTable declaration. The TableFile()
instruction writes data to the memory card based on user-specified parameters that
determine the file size based on number of records to store, or an interval over
which to store data. The resulting file is saved with a suffix of X.dat, where X is a
number that is incremented each time a new file is written.
DataTable(TableName,TriggerVariable,Size)
TableFile(FileName...LastFileName)
'Output processing instructions go here
EndTable
For example, in micrometeorological applications, TableFile() with Option 64 is
used to create a new high-frequency data file once per day. The size of the file
created is a function of the datalogger scan frequency and the number of variables
saved to the data table. For a typical eddy-covariance station, this daily file is
about 50 MB large (10 Hz scan frequency and 15 IEEE4 data points). CRBasic
example Using TableFile() with Option 64 with CF Cards (p. 207) is an example of
a micromet application.
CRBasic Example 39.
Using TableFile() with Option 64 with CF Card
'This program example demonstrates the use of TableFile() with Option 64 in micrometeorology
'eddy-covariance programs. The file naming scheme used in instruction TableFile() is
'customized using variables, constants, and text.
Public Sensor(10)
DataTable(Ts_data,TRUE,-1)
'TableFile("filename",Option,MaxFiles,NumRec/TimeIntoInterval,Interval,Units,
' OutStat,LastFileName)
TableFile("CRD:"&Status.SerialNumber(1,1)&".ts_data_",64,-1,0,1,Day,0,0)
Sample(10,sensor(1),IEEE4)
EndTable
BeginProg
Scan(100,mSec,100,0)
'Measurement instructions go here.
'Processing instructions go here.
CallTable ts_data
NextScan
EndProg
7.9.11.4 Converting TOB3 Files with CardConvert
The TOB3 format that is used to write data to memory cards saves disk space.
However, the resulting binary files must be converted to another format to be read
or used by other programs. The CardConvert software, included in Campbell
Scientific datalogger support software (p. 95), will convert data files from one
format to another. CardConvert Help has more details.
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Section 7. Installation
7.9.11.5 TableFile() with Option 64 Q & A
Q: How does Option 64 differ from other TableFile() options?
A: Pre-allocation of memory combines with TOB3 data format to give Option 64
two principal advantages over other TableFile() options. These are:
x
x
increased runtime write performance
short card eject times
Option 64 is unique among table file options in that it pre-allocates enough
memory on the memory card to store an interval amount of data1. Pre-allocation
DOORZVGDWDWREHFRQWLQXRXVO\DQGPRUHTXLFNO\ZULWWHQWRWKHFDUGLQ§.%
blocks. TOB3 binary format copies data directly from CPU memory to the
memory card without format conversion, lending additional speed and efficiency
to the data storage process.
Note Pre-allocation of memory card files significantly increases run time write
performance. It also reduces the risk of file corruption that can occur as a result
of power loss or incorrect card removal.
Note To avoid data corruption and loss, memory card removal must always be
initiated by pressing the Initiate Removal button on the face of the NL115 or
CFM100 modules. The card must be ejected only after the Status light shows a
solid green.
Q: Why are individual files limited to 2 GB?
A: In common with many other systems, the datalogger natively supports signed
four-byte integers. This data type can represent a number as large as 231, or in
terms of bytes, roughly 2 GB. This is the maximum file length that can be
represented in the datalogger directory table.
Q: Why does a large card cause long program compile times?
A: Program compile times increase with card and file sizes. As the datalogger
boots up, the card must be searched to determine space available for data storage.
In addition, for tables that are created by TableFile() with Option 64, an empty
file that is large enough to hold all of the specified records must be created (i.e.,
memory is pre-allocated). When using TableFile() with Option 64, program
compile times can be lessened by reducing the number of records or data-output
interval that will be included in each file. For example, if the maximum file size
specified is 2 GB, the datalogger must scan through and pre-allocate 2 GB of CF
card memory. However, if smaller files are specified, then compile times are
reduced because the datalogger is only required to scan through enough memory
to pre-allocate memory for the smaller file.
Q: Why does a freshly formatted card cause long compile times?
A: Program compile times take longer with freshly formatted cards because the
cards use a FAT32 system (File Allocation Table with 32 table element bits) to be
compatible with PCs. To avoid long compile times on a freshly formatted card,
format the card on a PC, then copy a small file to the card, and then delete the file
(while still in the PC). Copying the file to the freshly formatted card forces the
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Section 7. Installation
PC to update the info sector. The PC is much faster than the datalogger at
updating the info sector.
FAT32 uses an “info sector” to store the free cluster information. This info sector
prevents the need to repeatedly traverse the FAT for the bytes free information.
After a card is formatted by a PC, the info sector is not automatically updated.
Therefore, when the datalogger boots up, it must determine the bytes available on
the card prior to loading the Status table. Traversing the entire FAT of a 16 GB
card can take up to 30 minutes or more. However, subsequent compile times are
much shorter because the info sector is used to update the bytes free information.
Q: Which memory card should I use?
A: Campbell Scientific recommends and supports only the use of FMJ brand CF
cards. These cards are industrial-grade and have passed Campbell Scientific
hardware testing. Following are listed advantages these cards have over less
expensive commercial-grade cards:
x
x
x
x
x
less susceptible to failure and data loss
match the datalogger operating temperature range
faster read/write times
better vibration and shock resistance
longer life spans (more read/write cycles)
Note More CF card recommendations are presented in the application note, CF
Card Information, which is available at www.campbellsci.com.
Q: Can closed files be retrieved remotely?
A: Yes. Closed files can be retrieved using the Retrieve function in the
datalogger support software File Control (p. 515) utility, FTP, HTTP, or e-mail.
Although open files will appear in the CRD: drive directory, do not attempt to
retrieve open files. Doing so may corrupt the file and result in data loss. Smaller
files typically transmit more quickly and more reliably than large files.
Q: Can data be accessed?
A: Yes. Data in the open or most recent file can be collected using the Collect or
Custom Collect utilities in LoggerNet, PC400, or RTDAQ. Data can also be
viewed using datalogger support software or accessed through the datalogger
using data table access syntax such as TableName.FieldName (see CRBasic
Editor Help). Once a file is closed, data can be accessed only by first retrieving
the file, as discussed previously, and processing the file using CardConvert
software.
Q: What happens when a card is inserted?
A: When a card is inserted, whether it is a new card or the previously used card, a
new file is always created.
Q: What does a power cycle or program restart do?
A: Each time the program starts, whether by user control, power cycle, or a
watchdog, TableFile() with Option 64 will create a new file.
209
Section 7. Installation
Q: What happens when a card is filled?
A: If the memory card fills, new data are written over oldest data. A card must be
exchanged before it fills, or the oldest data will be overwritten by incoming new
records and lost. During the card exchange, once the old card is removed, the new
card must be inserted before the data table in datalogger CPU memory rings2, or
data will be overwritten and lost. For example, consider an application wherein
the data table in datalogger CPU memory has a capacity for about 45 minutes of
data3. The exchange must take place anytime before the 45 minutes expire. If the
exchange is delayed by an additional 5 minutes, 5 minutes of data at the beginning
of the last 45 minute interval (since it is the oldest data) will be overwritten in
CPU memory before transfer to the new card and lost.
1
Other options of TableFile() do not pre-allocate memory, so they should be avoided when collecting
high-frequency time-series data. More information is available in CRBasic Editor Help.
2
"rings": the datalogger has a ring memory. In other words, once filled, rather than stopping when
full, oldest data are overwritten by new data. In this context, "rings" designates when new data begins
to overwrite the oldest data.
3
CPU data table fill times can be confirmed in the datalogger Status table.
7.9.12 Field Calibration — Details
Related Topics:
‡Field Calibration — Overview (p. 73)
‡Field Calibration — Details (p. 210)
Calibration increases accuracy of a sensor by adjusting or correcting its output to
match independently verified quantities. Adjusting a sensor output signal is
preferred, but not always possible or practical. By using the FieldCal() or
FieldCalStrain() instruction, a linear sensor output can be corrected in the
CR1000 after the measurement by adjusting the multiplier and offset.
When included in the CRBasic program, FieldCal() and FieldCalStrain() can be
used through a datalogger support software calibration wizard (p. 509). Help for
using the wizard is available in the software.
A more arcane procedure that does not require a PC can be executed though the
CR1000KD Keyboard / Display. If you do not have a keyboard, the same
procedure can be done in a numeric monitor (p. 521). Numeric monitor screen
captures are used in the following procedures. Running through these procedures
will give you a foundation for how field calibration works, but use of the
calibration wizard for routine work is recommended.
Syntax of FieldCal() and FieldCalStrain() is summarized in the section
Calibration Functions (p. 598). More detail is available in CRBasic Editor Help.
7.9.12.1 Field Calibration CAL Files
Calibration data are stored automatically, usually on the CR1000 CPU: drive, in
CAL (.cal) files. These data become the source for calibration factors when
requested by the LoadFieldCal() instruction. A file is created automatically on
the same CR1000 memory drive and given the same name as the program that
creates and uses it. For example, the CRBasic program file CPU:MyProg.cr1
generates the CAL file CPU:MyProg.cal.
210
Section 7. Installation
CAL files are created if a program using FieldCal() or FieldCalStrain() does not
find an existing, compatible CAL file. Files are updated with each successful
calibration with new calibration factors factors. A calibration history is recorded
only if the CRBasic program creates a data table (p. 512) with the
SampleFieldCal() instruction.
Note CAL files created by FieldCal() and FieldCalStrain() differ from files
created by the CalFile() instruction (File Management (p. 382)).
7.9.12.2 Field Calibration Programming
Field-calibration functionality is included in a CRBasic program through either of
the following instructions:
x
x
FieldCal() — the principal instruction used for non-strain gage type sensors.
For introductory purposes, use one FieldCal() instruction and a unique set of
FieldCal() variables for each sensor. For more advanced applications, use
variable arrays.
FieldCalStrain() — the principal instruction used for strain gages measuring
microstrain. Use one FieldCalStrain() instruction and a unique set of
FieldCalStrain() variables for each sensor. For more advanced applications,
use variable arrays.
FieldCal() and FieldCalStrain() use the following instructions:
x
x
LoadFieldCal() — an optional instruction that evaluates the validity of, and
loads values from a CAL file.
SampleFieldCal — an optional data-storage output instruction that writes the
latest calibration values to a data table (not to the CAL file).
FieldCal() and FieldCalStrain() use the following reserved Boolean variable:
x
NewFieldCal — a reserved Boolean variable under CR1000 control used to
optionally trigger a data storage output table one time after a calibration has
succeeded.
See CRBasic Editor Help for operational details on CRBasic instructions.
7.9.12.3 Field Calibration Wizard Overview
The LoggerNet and RTDAQ field calibration wizards step you through the
procedure by performing the mode-variable changes and measurements
automatically. You set the sensor to known values and input those values into the
wizard.
When a program with FieldCal() or FieldCalStrain() is running, select
LoggerNet or RTDAQ | Datalogger | Calibration Wizard to start the wizard. A
list of measurements used is shown.
For more information on using the calibration wizard, consult LoggerNet or
RTDAQ Help.
7.9.12.4 Field Calibration Numeric Monitor Procedures
Manual field calibration through the numeric monitor (in lieu of a CR1000KD
Keyboard / Display is presented here to introduce the use and function of the
FieldCal() and FieldCalStrain() instructions. This section is not a
211
Section 7. Installation
comprehensive treatment of field-calibration topics. The most comprehensive
resource to date covering use of FieldCal() and FieldCalStrain() is RTDAQ
software documentation available at www.campbellsci.com
http://www.campbellsci.com. Be aware of the following precautions:
x
x
The CR1000 does not check for out-of-bounds values in mode variables.
Valid mode variable entries are 1 or 4.
Before, during, and after calibration, one of the following codes will be stored in
the CalMode variable:
Table 28. FieldCal() Codes
Value Returned
7.9.12.4.1
State
-1
Error in the calibration setup
-2
Multiplier set to 0 or NAN; measurement = NAN
-3
Reps is set to a value other than 1 or the size of MeasureVar
0
No calibration
1
Ready to calculate (KnownVar holds the first of a two point
calibration)
2
Working
3
First point done (only applicable for two point calibrations)
4
Ready to calculate (KnownVar holds the second of a two-point
calibration)
5
Working (only applicable for two point calibrations)
6
Calibration complete
One-Point Calibrations (Zero or Offset)
Zero operation applies an offset of equal magnitude but opposite sign. For
example, when performing a zeroing operation on a measurement of 15.3, the
value –15.3 will be added to subsequent measurements.
Offset operation applies an offset of equal magnitude and same sign. For
example, when performing an offset operation on a measurement of 15.3, the
value 15.3 will be added to subsequent measurements.
See FieldCal() Zero or Tare (Opt 0) Example (p. 214) and FieldCal() Offset (Opt 1)
Example (p. 216) for demonstration programs:
1. Use a separate FieldCal() instruction and variables for each sensor to be
calibrated. In the CRBasic program , put the FieldCal() instruction
immediately below the associated measurement instruction.
2. Set mode variable = 0 or 6 before starting.
3. Place the sensor into zeroing or offset condition.
4. Set KnownVar variable to the offset or zero value.
5. Set mode variable = 1 to start calibration.
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Section 7. Installation
7.9.12.4.2
Two-Point Calibrations (gain and offset)
Use this two-point calibration procedure to adjust multipliers (slopes) and offsets
(y intercepts). See FieldCal() Slope and Offset (Opt 2) Example (p. 218) and
FieldCal() Slope (Opt 3) Example (p. 220) for demonstration programs:
1. Use a separate FieldCal() instruction and separate variables for each sensor to
be calibrated.
2. Ensure mode variable = 0 or 6 before starting.
a. If Mode > 0 DQG6, calibration is in progress.
b. If Mode < 0, calibration encountered an error.
3. Place sensor into first known point condition.
4. Set KnownVar variable to first known point.
5. Set Mode variable = 1 to start first part of calibration.
a. Mode = 2 (automatic) during the first point calibration.
b. Mode = 3 (automatic) when the first point is completed.
6. Place sensor into second known point condition.
7. Set KnownVar variable to second known point.
8. Set Mode = 4 to start second part of calibration.
a. Mode = 5 (automatic) during second point calibration.
b. Mode = 6 (automatic) when calibration is complete.
7.9.12.4.3
Zero Basis Point Calibration
Zero-basis calibration (FieldCal() instruction Option 4) is designed for use with
static vibrating-wire measurements. It loads values into zero-point variables
to track conditions at the time of the zero calibration. See FieldCal() Zero
Basis (Opt 4) Example (p. 223) for a demonstration program.
7.9.12.5 Field Calibration Examples
FieldCal() has the following calibration options:
x
x
x
x
x
Zero
Offset
Two-point slope and offset
Two-point slope only
Zero basis (designed for use with static vibrating-wire measurements)
These demonstration programs are provided as an aid in becoming familiar with
the FieldCal() features at a test bench without actual sensors. For the purpose of
the demonstration, sensor signals are simulated by CR1000 terminals configured
for excitation. To reset tests, use the support software File Control (p. 515) menu
commands to delete .cal files, and then send the demonstration program again to
the CR1000. Term equivalents are as follows:
"offset" = "y- intercept" = "zero"
"multiplier" = "slope" = "gain"
213
Section 7. Installation
7.9.12.5.1
FieldCal() Zero or Tare (Opt 0) Example
Most CRBasic measurement instructions have a multiplier and offset parameter.
FieldCal() Option 0 adjusts the offset argument such that the output of the sensor
being calibrated is set to the value of the FieldCal() KnownVar parameter, which
is set to 0. Subsequent measurements have the same offset subtracted. Option 0
does not affect the multiplier argument.
Example Case: A sensor measures the relative humidity (RH) of air. Multiplier is
known to be stable, but sensor offset drifts and requires regular zeroing in a
desiccated chamber. The following procedure zeros the RH sensor to obtain the
calibration report shown. To step through the example, use the CR1000KD
Keyboard Display or software numeric monitor (p. 521) to change variable values as
directed.
Table 29. Calibration Report for Relative Humidity Sensor
CRBasic Variable
At Deployment
At 30-Day Service
SimulatedRHSignal output
100 mV
105 mV
KnownRH (desiccated
chamber)
0%
0%
RHMultiplier
0.05 % / mV
0.05 % / mV
RHOffset
-5 %
-5.25 %
RH
0%
0%
1. Send CRBasic example FieldCal() Zero (p. 214) to the CR1000. A terminal
configured for excitation has been programmed to simulate a sensor output.
2. To place the simulated RH sensor in a simulated-calibration condition (in the
field it would be placed in a desiccated chamber), place a jumper wire between
terminals VX1 and SE1. The following variables are preset by the program:
SimulatedRHSignal = 100, KnownRH = 0.
3. To start the 'calibration', set variable CalMode = 1. When CalMode increments
to 6, zero calibration is complete. Calibrated RHOffset will equal -5% at this
stage of this example.
4. To continue this example and simulate a zero-drift condition, set variable
SimulatedRHSignal = 105.
5. To simulate conditions for a 30-day-service calibration, again with desiccated
chamber conditions, keep variable KnownRH = 0.0. Set variable CalMode =
1 to start calibration. When CalMode increments to 6, simulated 30-dayservice zero calibration is complete. Calibrated RHOffset will equal -5.2 %.
214
Section 7. Installation
CRBasic Example 40.
FieldCal() Zero
'This program example demonstrates the use of FieldCal() in calculating and applying a zero
'calibration. A zero calibration measures the signal magnitude of a sensor in a known zero
'condition and calculates the negative magnitude to use as an offset in subsequent
'measurements. It does not affect the multiplier.
'
'This program demonstrates the zero calibration with the following procedure:
' -- Simulate a signal from a relative-humidity sensor.
' -- Measure the 'sensor' signal.
' -- Calculate and apply a zero calibration.
'You can set up the simulation by loading this program into the CR1000 and interconnecting
'the following terminals with a jumper wire to simulate the relative-humidity sensor signal
'as follows:
' Vx1 --- SE1
'For the simulation, the initial 'sensor' signal is set automatically. Start the zero routine
'by setting variable CalMode = 1. When CalMode = 6 (will occur automatically after 10
'measurements), the routine is complete. Note the new value in variable RHOffset. Now
'enter the following millivolt value as the simulated sensor signal and note how the new
'offset is added to the measurement:
' SimulatedRHSignal = 1000
'NOTE: This program places a .cal file on the CPU: drive of the CR1000. The .cal file must
'be erased to reset the demonstration.
'DECLARE SIMULATED SIGNAL VARIABLE AND SET INITIAL MILLIVOLT SIGNAL MAGNITUDE
Public SimulatedRHSignal = 100
'DECLARE CALIBRATION STANDARD VARIABLE AND SET PERCENT RH MAGNITUDE
Public KnownRH = 0
'DECLARE MEASUREMENT RESULT VARIABLE.
Public RH
'DECLARE OFFSET RESULT VARIABLE
Public RHOffset
'DECLARE VARIABLE FOR FieldCal() CONTROL
Public CalMode
'DECLARE DATA TABLE FOR RETRIEVABLE CALIBRATION RESULTS
DataTable(CalHist,NewFieldCal,200)
SampleFieldCal
EndTable
BeginProg
'LOAD CALIBRATION CONSTANTS FROM FILE CPU:CALHIST.CAL
'Effective after the zero calibration procedure (when variable CalMode = 6)
LoadFieldCal(true)
215
Section 7. Installation
Scan(100,mSec,0,0)
'SIMULATE SIGNAL THEN MAKE THE MEASUREMENT
'Zero calibration is applied when variable CalMode = 6
ExciteV(Vx1,SimulatedRHSignal,0)
VoltSE(RH,1,mV2500,1,1,0,250,0.05,RHOffset)
'PERFORM A ZERO CALIBRATION.
'Start by setting variable CalMode = 1. Finished when variable CalMode = 6.
'FieldCal(Function, MeasureVar, Reps, MultVar, OffsetVar, Mode, KnownVar, Index, Avg)
FieldCal(0,RH,1,0,RHOffset,CalMode,KnownRH,1,30)
'If there was a calibration, store calibration values into data table CalHist
CallTable(CalHist)
NextScan
EndProg
7.9.12.5.2
FieldCal() Offset (Opt 1) Example
Most CRBasic measurement instructions have a multiplier and offset parameter.
FieldCal() Option 1 adjusts the offset argument such that the output of the sensor
being calibrated is set to the magnitude of the FieldCal() KnownVar parameter.
Subsequent measurements have the same offset added. Option 0 does not affect
the multiplier argument. Option 0 does not affect the multiplier argument.
Example Case: A sensor measures the salinity of water. Multiplier is known to be
stable, but sensor offset drifts and requires regular offset correction using a
standard solution. The following procedure offsets the measurement to obtain the
calibration report shown.
Table 30. Calibration Report for Salinity Sensor
CRBasic Variable
At Deployment
At Seven-Day Service
SimulatedSalinitySignal output
1350 mV
1345 mV
KnownSalintiy (standard
solution)
30 mg/l
30 mg/l
SalinityMultiplier
0.05 mg/l/mV
0.05 mg/l/mV
SalinityOffset
-37.50 mg/l
-37.23 mg/l
Salinity reading
30 mg/l
30 mg/l
1. Send CRBasic example FieldCal() Offset (p. 217) to the CR1000. A terminal
configured for excitation has been programmed to simulate a sensor output.
2. To simulate the salinity sensor in a simulated-calibration condition, (in the field
it would be placed in a 30 mg/l standard solution), place a jumper wire
between terminals VX1 and SE1. The following variables are preset by the
program: SimulatedSalinitySignal = 1350, KnownSalinity = 30.
3. To start a simulated calibration, set variable CalMode = 1. When CalMode
increments to 6, offset calibration is complete. The calibrated offset will equal
-37.48 mg/l.
4. To continue this example and simulate an offset-drift condition, set variable
SimulatedSalinitySignal = 1345.
216
Section 7. Installation
5. To simulate seven-day-service calibration conditions (30 mg/l standard
solution), the variable KnownSalinity remains at 30.0. Change the value in
variable CalMode to 1 to start the calibration. When CalMode increments to 6,
the seven-day-service offset calibration is complete. Calibrated offset will
equal -37.23 mg/l.
CRBasic Example 41.
FieldCal() Offset
'This program example demonstrates the use of FieldCal() in calculating and applying an
'offset calibration. An offset calibration compares the signal magnitude of a sensor to a
'known standard and calculates an offset to adjust the sensor output to the known value.
'The offset is then used to adjust subsequent measurements.
'This program demonstrates the offset calibration with the following procedure:
' -- Simulate a signal from a salinity sensor.
' -- Measure the 'sensor' signal.
' -- Calculate and apply an offset.
'
'You can set up the simulation by loading this program into the CR1000 and interconnecting the
'following terminals with a jumper wire to simulate the salinity sensor signal as follows:
' Vx1 --- SE1
'For the simulation, the value of the calibration standard and the initial 'sensor' signal
'are set automatically. Start the calibration routine by setting variable CalMode = 1. When
'CalMode = 6 (will occur automatically after 10 measurements), the routine is complete.
'Note the new value in variable SalinityOffset. Now enter the following millivolt value as
'the simulated sensor signal and note how the new offset is added to the measurement:
' SimulatedSalinitySignal = 1345
'NOTE: This program places a .cal file on the CPU: drive of the CR1000. The .cal file must
'be erased to reset the demonstration.
'DECLARE SIMULATED SIGNAL VARIABLE AND SET INITIAL MAGNITUDE
Public SimulatedSalinitySignal = 1350
'mg/l
'DECLARE CALIBRATION STANDARD VARIABLE AND SET MAGNITUDE
Public KnownSalinity = 30
'mg/l
'DECLARE MEASUREMENT RESULT VARIABLE.
Public Salinity
'DECLARE OFFSET RESULT VARIABLE
Public SalinityOffset
'DECLARE VARIABLE FOR FieldCal() CONTROL
Public CalMode
'DECLARE DATA TABLE FOR RETRIEVABLE CALIBRATION RESULTS
DataTable(CalHist,NewFieldCal,200)
SampleFieldCal
EndTable
217
Section 7. Installation
BeginProg
'LOAD CALIBRATION CONSTANTS FROM FILE CPU:CALHIST.CAL
'Effective after the zero calibration procedure (when variable CalMode = 6)
LoadFieldCal(true)
Scan(100,mSec,0,0)
'SIMULATE SIGNAL THEN MAKE THE MEASUREMENT
'Zero calibration is applied when variable CalMode = 6
ExciteV(Vx1,SimulatedSalinitySignal,0)
VoltSE(Salinity,1,mV2500,1,1,0,250,0.05,SalinityOffset)
'PERFORM AN OFFSET CALIBRATION.
'Start by setting variable CalMode = 1. Finished when variable CalMode = 6.
'FieldCal(Function, MeasureVar, Reps, MultVar, OffsetVar, Mode, KnownVar, Index, Avg)
FieldCal(1,Salinity,1,0,SalinityOffset,CalMode,KnownSalinity,1,30)
'If there was a calibration, store calibration values into data table CalHist
CallTable(CalHist)
NextScan
EndProg
7.9.12.5.3
FieldCal() Slope and Offset (Opt 2) Example
Most CRBasic measurement instructions have a multiplier and offset parameter.
FieldCal() Option 2 adjusts the multiplier and offset arguments such that the
output of the sensor being calibrated is set to a value consistent with the linear
relationship that intersects two known points sequentially entered in the
FieldCal() KnownVar parameter. Subsequent measurements are scaled with the
same multiplier and offset.
Example Case: A meter measures the volume of water flowing through a pipe.
Multiplier and offset are known to drift, so a two-point calibration is required
periodically at known flow rates. The following procedure adjusts multiplier and
offset to correct for meter drift as shown in the calibration report below. Note that
the flow meter outputs millivolts inversely proportional to flow.
Table 31. Calibration Report for Flow Meter
CRBasic Variable
At Deployment
At Seven-Day Service
SimulatedFlowSignal
300 mV
285 mV
KnownFlow
30 L/s
30 L/s
SimulatedFlowSignal
550 mV
522 mV
KnownFlow
10 L/s
10 L/s
FlowMultiplier
-0.0799 L/s/mV
-0.0841 L/s/mV
FlowOffset
53.90 L
53.92 L
1. Send CRBasic example FieldCal() Two-Point Slope and Offset (p. 219) to the
CR1000.
2. To place the simulated flow sensor in a simulated calibration condition (in the
field a real sensor would be placed in a condition of know flow), place a
218
Section 7. Installation
jumper wire between terminals VX1 and SE1.
3. Perform the simulated deployment calibration as follows:
a. For the first point, set variable SimulatedFlowSignal = 300. Set variable
KnownFlow = 30.0.
b. Start the calibration by setting variable CalMode = 1.
c. When CalMode increments to 3, for the second point, set variable
SimulatedFlowSignal = 550. Set variable KnownFlow = 10.
d. Resume the deployment calibration by setting variable CalMode = 4
4. When variable CalMode increments to 6, the deployment calibration is
complete. Calibrated multiplier is -0.08; calibrated offset is 53.9.
5. To continue this example, suppose the simulated sensor multiplier and offset
drift. Simulate a seven-day service calibration to correct the drift as follows:
a. Set variable SimulatedFlowSignal = 285. Set variable KnownFlow =
30.0.
b. Start the seven-day service calibration by setting variable CalMode = 1.
c. When CalMode increments to 3, set variable SimulatedFlowSignal = 522.
Set variable KnownFlow = 10.
d. Resume the calibration by setting variable CalMode = 4
6. When variable CalMode increments to 6, the calibration is complete. The
corrected multiplier is -0.08; offset is 53.9.
CRBasic Example 4Ϯ.
FieldCal() Two-Point Slope and Offset
'This program example demonstrates the use of FieldCal() in calculating and applying a
'multiplier and offset calibration. A multiplier and offset calibration compares signal
'magnitudes of a sensor to known standards. The calculated multiplier and offset scale the
'reported magnitude of the sensor to a value consistent with the linear relationship that
'intersects known points sequentially entered in to the FieldCal() KnownVar parameter.
'Subsequent measurements are scaled by the new multiplier and offset.
'This
' -' -' --
program demonstrates the multiplier and offset calibration with the following procedure:
Simulate a signal from a flow sensor.
Measure the 'sensor' signal.
Calculate and apply a multiplier and offset.
'You can set up the simulation by loading this program into the CR1000 and interconnecting
'the following terminals with a jumper wire to simulate a flow sensor signal as follows:
' Vx1 --- SE1
'For the simulation, the value of the calibration standard and the initial 'sensor' signal
'are set automatically. Start the multiplier-and-offset routine by setting variable
'CalMode = 1. The value in CalMode will increment automatically. When CalMode = 3, set
'variables SimulatedFlowSignal = 550 and KnownFlow = 10, then set CalMode = 4. CalMode
'will again increment automatically. When CalMode = 6 (occurs automatically after 10
219
Section 7. Installation
'measurements), the routine is complete. Note the new values in variables FlowMultiplier and
'FlowOffest. Now enter a new value in the simulated sensor signal as follows and note
'how the new multiplier and offset scale the measurement:
' SimulatedFlowSignal = 1000
'NOTE: This program places a .cal file on the CPU: drive of the CR1000. The .cal file must
'be erased to reset the demonstration.
'DECLARE SIMULATED SIGNAL VARIABLE AND SET INITIAL MAGNITUDE
Public SimulatedFlowSignal = 300
'Excitation mV, second setting is 550
'DECLARE CALIBRATION STANDARD VARIABLE AND SET MAGNITUDE
Public KnownFlow = 30
'Known flow, second setting is 10
'DECLARE MEASUREMENT RESULT VARIABLE.
Public Flow
'DECLARE MULTIPLIER AND OFFSET RESULT VARIABLES AND SET INITIAL MAGNITUDES
Public FlowMultiplier = 1
Public FlowOffset = 0
'DECLARE VARIABLE FOR FieldCal() CONTROL
Public CalMode
'DECLARE DATA TABLE FOR RETRIEVABLE CALIBRATION RESULTS
DataTable(CalHist,NewFieldCal,200)
SampleFieldCal
EndTable
BeginProg
'LOAD CALIBRATION CONSTANTS FROM FILE CPU:CALHIST.CAL
'Effective after the zero calibration procedure (when variable CalMode = 6)
LoadFieldCal(true)
Scan(100,mSec,0,0)
'SIMULATE SIGNAL THEN MAKE THE MEASUREMENT
'Multiplier calibration is applied when variable CalMode = 6
ExciteV(Vx1,SimulatedFlowSignal,0)
VoltSE(Flow,1,mV2500,1,1,0,250,FlowMultiplier,FlowOffset)
'PERFORM A MULTIPLIER CALIBRATION.
'Start by setting variable CalMode = 1. Finished when variable CalMode = 6.
'FieldCal(Function, MeasureVar, Reps, MultVar, OffsetVar, Mode, KnownVar, Index, Avg)
FieldCal(2,Flow,1,FlowMultiplier,FlowOffset,CalMode,KnownFlow,1,30)
'If there was a calibration, store it into a data table
CallTable(CalHist)
NextScan
EndProg
7.9.12.5.4
FieldCal() Slope (Opt 3) Example
Most CRBasic measurement instructions have a multiplier and offset parameter.
FieldCal() Option 3 adjusts the multiplier argument such that the output of the
sensor being calibrated is set to a value consistent with the linear relationship that
220
Section 7. Installation
intersects two known points sequentially entered in the FieldCal() KnownVar
parameter. Subsequent measurements are scaled with the same multiplier.
FieldCal() Option 3 does not affect offset.
Some measurement applications do not require determination of offset.
Frequency analysis, for example, may only require relative data to characterize
change.
Example Case: A soil-water sensor is to be used to detect a pulse of water moving
through soil. A pulse of soil water can be detected with an offset, but sensitivity
to the pulse is important, so an accurate multiplier is essential. To adjust the
sensitivity of the sensor, two soil samples, with volumetric water contents of 10%
and 35%, will provide two known points.
Table 32. Calibration Report for Water Content Sensor
CRBasic Variable
SimulatedWaterContentSignal
KnownWC
SimulatedWaterContentSignal
KnownWC
WCMultiplier
At Deployment
175 mV
10 %
700 mV
35 %
0.0476 %/mV
The following procedure sets the sensitivity of a simulated soil water-content
sensor.
1. Send CRBasic example FieldCal() Multiplier (p. 221) to the CR1000.
2. To simulate the soil-water sensor signal, place a jumper wire between terminals
VX1 and SE1.
3. Simulate deployment-calibration conditions in two stages as follows:
a. Set variable SimulatedWaterContentSignal to 175. Set variable
KnownWC to 10.0.
b. Start the calibration by setting variable CalMode = 1.
c. When CalMode increments to 3, set variable
SimulatedWaterContentSignal to 700. Set variable KnownWC to 35.
d. Resume the calibration by setting variable CalMode = 4
4. When variable CalMode increments to 6, the calibration is complete.
Calibrated multiplier is 0.0476.
CRBasic Example 43.
FieldCal() Multiplier
'This program example demonstrates the use of FieldCal() in calculating and applying a
'multiplier only calibration. A multiplier calibration compares the signal magnitude of a
'sensor to known standards. The calculated multiplier scales the reported magnitude of the
'sensor to a value consistent with the linear relationship that intersects known points
'sequentially entered in to the FieldCal() KnownVar parameter. Subsequent measurements are
'scaled by the multiplier.
221
Section 7. Installation
'This program demonstrates the multiplier calibration with the following procedure:
' -- Simulate a signal from a water content sensor.
' -- Measure the 'sensor' signal.
' -- Calculate and apply an offset.
'
'You can set up the simulation by loading this program into the CR1000 and interconnecting
'the following terminals with a jumper wire to simulate a water content sensor signal as
'follows:
' Vx1 --- SE1
'For the simulation, the value of the calibration standard and the initial 'sensor'
'are set automatically. Start the multiplier routine by setting variable CalMode =
'CalMode = 6 (occurs automatically after 10 measurements), the routine is complete.
'new value in variable WCMultiplier. Now enter a new value in the simulated sensor
'as follows and note how the new multiplier scales the measurement:
' SimulatedWaterContentSignal = 350
signal
1. When
Note the
signal
'NOTE: This program places a .cal file on the CPU: drive of the CR1000. The .cal file must
'be erased to reset the demonstration.
'DECLARE SIMULATED SIGNAL VARIABLE AND SET INITIAL MAGNITUDE
Public SimulatedWaterContentSignal = 175
'mV, second setting is 700 mV
'DECLARE CALIBRATION STANDARD VARIABLE AND SET MAGNITUDE
Public KnownWC = 10
'% by Volume, second setting is 35%
'DECLARE MEASUREMENT RESULT VARIABLE.
Public WC
'DECLARE MULTIPLIER RESULT VARIABLE AND SET INITIAL MAGNITUDE
Public WCMultiplier = 1
'DECLARE VARIABLE FOR FieldCal() CONTROL
Public CalMode
'DECLARE DATA TABLE FOR RETRIEVABLE CALIBRATION RESULTS
DataTable(CalHist,NewFieldCal,200)
SampleFieldCal
EndTable
BeginProg
'LOAD CALIBRATION CONSTANTS FROM FILE CPU:CALHIST.CAL
'Effective after the zero calibration procedure (when variable CalMode = 6)
LoadFieldCal(true)
Scan(100,mSec,0,0)
'SIMULATE SIGNAL THEN MAKE THE MEASUREMENT
'Multiplier calibration is applied when variable CalMode = 6
ExciteV(Vx1,SimulatedWaterContentSignal,0)
VoltSE(WC,1,mV2500,1,1,0,250,WCMultiplier,0)
222
Section 7. Installation
'PERFORM A MULTIPLIER CALIBRATION.
'Start by setting variable CalMode = 1. Finished when variable CalMode = 6.
'FieldCal(Function, MeasureVar, Reps, MultVar, OffsetVar, Mode, KnownVar, Index, Avg)
FieldCal(3,WC,1,WCMultiplier,0,CalMode,KnownWC,1,30)
'If there was a calibration, store it into data table CalHist
CallTable(CalHist)
NextScan
EndProg
7.9.12.5.5
FieldCal() Zero Basis (Opt 4) Example -- 8 10 30
Zero-basis calibration (FieldCal() instruction Option 4) is designed for use in
static vibrating-wire measurements. For more information, refer to these
manuals available at www.campbellsci.com:
AVW200-Series Two-Channel VSPECT Vibrating-Wire Measurement Device
CR6 Measurement and Control Datalogger Operators Manual
7.9.12.6 Field Calibration Strain Examples
Related Topics:
‡Strain Measurements — Overview (p. 68)
‡Strain Measurements — Details (p. 342)
‡FieldCalStrain() Examples (p. 223)
Strain-gage systems consist of one or more strain gages, a resistive bridge in
which the gage resides, and a measurement device such as the CR1000
datalogger. The FieldCalStrain() instruction facilitates shunt calibration of
strain-gage systems and is designed exclusively for strain applications wherein
microstrain is the unit of measure. The FieldCal() instruction (FieldCal()
Examples (p. 213) ) is typically used in non-microstrain applications.
Shunt calibration of strain-gage systems is common practice. However, the
technique provides many opportunities for misapplication and misinterpretation.
This section is not intended to be a primer on shunt-calibration theory, but only to
introduce use of the technique with the CR1000 datalogger. Campbell Scientific
strongly urges users to study shunt-calibration theory from other sources. A
thorough treatment of strain gages and shunt-calibration theory is available from
Vishay using search terms such as 'micro-measurements', 'stress analysis', 'strain
gages', 'calculator list', at:
http://www.vishaypg.com
Campbell Scientific application engineers also have resources that may assist you
with strain-gage applications.
7.9.12.6.1
Field Calibration Strain Examples
1. Shunt calibration does not calibrate the strain gage itself.
2. Shunt calibration does compensate for long leads and non-linearity in the
resistive bridge. Long leads reduce sensitivity because of voltage drop.
FieldCalStrain() uses the known value of the shunt resistor to adjust the gain
(multiplier / span) to compensate. The gain adjustment (S) is incorporated by
FieldCalStrain() with the manufacturer's gage factor (GF), becoming the
223
Section 7. Installation
adjusted gage factor (GFadj), which is then used as the gage factor in
StrainCalc(). GF is stored in the CAL file and continues to be used in
subsequent calibrations. Non-linearity of the bridge is compensated for by
selecting a shunt resistor with a value that best simulates a measurement near
the range of measurements to be made. Strain-gage manufacturers typically
specify and supply a range of resistors available for shunt calibration.
3. Shunt calibration verifies the function of the CR1000.
4. The zero function of FieldCalStrain() allows a particular strain to be set as an
arbitrary zero, if desired. Zeroing is normally done after the shunt calibration.
Zero and shunt options can be combined ina single CRBasic program.
CRBasic example FieldCalStrain() Calibration (p. 225) is provided to demonstrate
use of FieldCalStrain() features. If a strain gage configured as shown in figure
Quarter-Bridge Strain-Gage with RC Resistor Shunt (p. 225) is not available, strain
signals can be simulated by building the simplHFLUFXLWVXEVWLWXWLQJDȍ
potentiometer for the strain gage. To reset calibration tests, use the support
software File Control (p. 515) menu to delete .cal files, and then send the
demonstration program again to the CR1000.
ExDPSOH&DVH$ȍVWUDLQJDJHLVSODFHGLQWRDUHVLVWLYHEULGJHDWSRVLWLRQ
R1. The resulting circuit is a quarter-bridge strain gage with alternate shuntresistor (Rc) positions shown. Gage specifications indicate that the gage factor is
2.0 and that wLWKDNȍVKXQWPHDVXUHPHQWVKRXOGEHDERXWPLFURVWUDLQ
Send CRBasic example FieldCalStrain() Calibration (p. 225) as a program to a
CR1000 datalogger.
7.9.12.6.2
Field Calibration Strain Examples
CRBasic example FieldCalStrain() Calibration (p. 225) is provided to demonstrate
use of FieldCalStrain() features. If a strain gage configured as shown in figure
Quarter-Bridge Strain-Gage with RC Resistor Shunt (p. 225) is not available, strain
signals can be siPXODWHGE\EXLOGLQJWKHVLPSOHFLUFXLWVXEVWLWXWLQJDȍ
potentiometer for the strain gage. To reset calibration tests, use the support
software File Control (p. 515) menu to delete .cal files, and then send the
demonstration program again to the CR1000.
Case$ȍVWUDLQJDJHLVSODFHGLQWRDUHVLVWLYHEULGJHDWSRVLWLRQ57KH
resulting circuit is a quarter-bridge strain gage with alternate shunt-resistor (Rc)
positions shown. Gage specifications indicate that the gage factor is 2.0 and that
ZLWKDNȍVKXQWPHDVXUHPHQWVKRXOGEHDERXWPLFURVWUDLQ
Send CRBasic example FieldCalStrain() Calibration (p. 225) as a program to a
CR1000 datalogger.
224
Section 7. Installation
Figure 58. Quarter-Bridge Strain-Gage with RC Resistor Shunt
CRBasic Example 44.
FieldCalStrain() Calibration
'This program example demonstrates the use of the FieldCalStrain() instruction by measuring
'quarter-bridge strain-gage measurements.
Public Raw_mVperV
Public MicroStrain
'Variables that are arguments in the Zero Function
Public Zero_Mode
Public Zero_mVperV
'Variables that are arguments in the Shunt Function
Public Shunt_Mode
Public KnownRes
Public GF_Adj
Public GF_Raw
'----------------------------- Tables ---------------------------DataTable(CalHist,NewFieldCal,50)
SampleFieldCal
EndTable
'//////////////////////////// PROGRAM ////////////////////////////
BeginProg
'Set Gage Factors
GF_Raw = 2.1
GF_Adj = GF_Raw 'The adj Gage factors are used in the calculation of uStrain
'If a calibration has been done, the following will load the zero or
'Adjusted GF from the Calibration file
LoadFieldCal(True)
225
Section 7. Installation
Scan(100,mSec,100,0)
'Measure Bridge Resistance
BrFull(Raw_mVperV,1,mV25,1,Vx1,1,2500,True ,True ,0,250,1.0,0)
'Calculate Strain for 1/4 Bridge (1 Active Element)
StrainCalc(microStrain,1,Raw_mVperV,Zero_mVperV,1,GF_Adj,0)
'Steps (1) & (3): Zero Calibration
'Balance bridge and set Zero_Mode = 1 in numeric monitor. Repeat after
'shunt calibration.
FieldCalStrain(10,Raw_mVperV,1,0,Zero_mVperV,Zero_Mode,0,1,10,0 ,microStrain)
'Step (2) Shunt Calibration
'After zero calibration, and with bridge balanced (zeroed), set
'KnownRes = to gage resistance (resistance of gage at rest), then set
'Shunt_Mode = 1. When Shunt_Mode increments to 3, position shunt resistor
'and set KnownRes = shunt resistance, then set Shunt_Mode = 4.
FieldCalStrain(13,MicroStrain,1,GF_Adj,0,Shunt_Mode,KnownRes,1,10,GF_Raw,0)
CallTable CalHist
NextScan
EndProg
7.9.12.6.3
FieldCalStrain() Quarter-Bridge Shunt Example
With CRBasic example FieldCalStrain() Calibration (p. 225) sent to the CR1000,
and the strain gage stable, use the CR1000KD Keyboard Display or software
numeric monitor to change the value in variable KnownRes to the nominal
resistance of the gage, 1000 ȍDVVKRZQLQILJXUHStrain-Gage Shunt Calibration
Start (p. 226). Set Shunt_Mode to 1 to start the two-point shunt calibration. When
Shunt_Mode increments to 3, the first step is complete.
To complete the calibration, shunt R1 with WKHNȍUHVLVWRU6HWYDULDEOH
KnownRes to 249000. As shown in figure Strain-Gage Shunt Calibration Finish
(p. 227), set Shunt_Mode to 4. When Shunt_Mode = 6, shunt calibration is
complete.
Figure 59. Strain-Gage Shunt Calibration Start
226
Section 7. Installation
Figure 60. Strain-Gage Shunt Calibration Finish
7.9.12.6.4
FieldCalStrain() Quarter-Bridge Zero
Continuing from FieldCalStrain() Quarter-Bridge Shunt Example (p. 226), keep the
NȍUHVLVWRULQSODFHWRVLPXODWHDVWUDLQ8VLQJWKH&5.'.H\ERDUG
Display or software numeric monitor, change the value in variable Zero_Mode to
1 to start the zero calibration as shown in figure Zero Procedure Start (p. 227).
When Zero_Mode increments to 6, zero calibration is complete as shown in
figure Zero Procedure Finish (p. 227).
Figure 61. Zero Procedure Start
Figure 62. Zero Procedure Finish
227
Section 7. Installation
7.9.13 Measurement: Excite, Delay, Measure
This example demonstrates how to make voltage measurements that require
excitation of controllable length prior to measurement. Overcoming the delay
caused by a very long cable length on a sensor is a common application for this
technique.
CRBasic Example 4ϱ.
Measurement with Excitation and Delay
'This program example demonstrates how to perform an excite/delay/measure operation.
'In this example, the system requires 1 s of excitation to stabilize before the sensors
'are measured. A single-ended measurement is made, and a separate differential measurement
'is made. To see this program in action, connect the following terminal pairs to simulate
'sensor connections:
'
'
'
'
'With
Vx1 ------ SE1
Vx2 ------ DIFF 2 H
DIFF 2 L ------ Ground Symbol
these connections made, variables VoltageSE and VoltageDiff will equal 2500 mV.
'Declare variables.
Public VoltageSE As Float
Public VoltageDIFF As Float
'Declare data table
DataTable (Voltage,True,-1)
Sample (1,VoltageSE,Float)
Sample (1,VoltageDIFF,Float)
EndTable
BeginProg
Scan(5,sec,0,0)
'Excite - delay 1 second - single-ended measurement:
ExciteV (Vx1,2500,0) '<<<<Note: Delay = 0
Delay (0,1000,mSec)
VoltSe (VoltageSE,1,mV5000,1,1,0,250,1.0,0)
'Excite - delay 1 second - differential measurement:
ExciteV (Vx2,2500,0) '<<<<Note: Delay = 0
Delay (0,1000,mSec)
VoltDiff (VoltageDIFF,1,mV5000,2,True,0,250,1.0,0)
'Write data to final-data memory
CallTable Voltage
NextScan
EndProg
228
Section 7. Installation
7.9.14 Measurement: Faster Analog Rates
Certain data acquisition applications require the CR1000 to make analog
measurements at rates faster than once per second (> 1 Hz (p. 517) ). The CR1000
can make continuous measurements at rates up to 100 Hz, and bursts (p. 509) of
measurements at rates up to 2000 Hz. Following is a discussion of fast
measurement programming techniques in association with VoltSE(), single-ended
analog voltage measurement instruction. Techniques discussed can also be used
with the following instructions:
VoltSE()
VoltDiff()
TCDiff()
TCSE()
BrFull()
BrFull6W()
BrHalf()
BrHalf3W()
BrHalf4W()
The table Summary of Analog Voltage Measurement Rates (p. 230), summarizes the
programming techniques used to make three classes of fast measurement: 100 Hz
maximum-rate, 600 Hz maximum-rate, and 2000 Hz maximum-rate. 100 Hz
measurements can have a 100% duty cycle (p. 514). That is, measurements are not
normally suspended to allow processing to catch up. Suspended measurements
equate to lost measurement opportunities and may not be desirable. 600 Hz and
2000 Hz measurements (measurements exceeding 100 Hz) have duty cycles less
than 100%.
229
Section 7. Installation
Table 33. Summary of Analog Voltage Measurement Rates
Maximum
Rate
Number of
Simultaneous Inputs
Maximum
Duty Cycle
Maximum
Measaurements
Per Burst
Description
100 Hz
600 Hz
2000 Hz
Multiple inputs
Fewer inputs
One input
100%
< 100%
< 100%
N/A
Variable
65535
Near simultaneous
measurements on multiple
channels
Near simultaneous
measurements on fewer
channels
Up to 8 sequential differential
or 16 single-ended channels.
Buffers maybe consumed and
only freed after a skipped scan.
Allocating more buffers usually
means more time will elapse
between skipped scans.
Buffers are continuously
"recycled", so no skipped scans.
A single CRBasic measurement
instruction bursts on one channel.
Multiple channels are measured
using multiple instructions, but
the burst on one channel
completes before the burst on the
next channel begins.
Analog Terminal
Sequence
Differential: 1, 2, 3, 4, 5, 6, 7, 8,
then repeat.
Single-ended: 1, 2, 3, 4, 5, 6, 7,
8, 9, 10, 11, 12, 13, 14, 15, 16,
then repeat.
Differential and single-ended:
1, 2, 1, 2, and so forth.
Excitation
for Bridge
Measurements
Provided in instruction.
Provided in instruction.
Provided in instruction.
Measurements per excitation
must equal Repetitions
Suggest using Scan() /
NextScan with ten (10) ms scan
interval. Program for the use of
up to 10 buffers.
Use Scan() / NextScan with a
20 ms or greater scan interval.
Program for the use of up to
100 buffers. Also use
SubScan() / NextSubScan with
1600 μs sub-scan and 12
counts.
Use Scan() / NextScan with one
(1) second scan interval. Analog
input Channel argument is
preceded by a dash (-).
CRBasic
Programming
Highlights
See CRBasic example
Measuring VoltSE() at 100 Hz
See CRBasic example
Measuring VoltSE() at 200 Hz
1, 1, 1… to completion, then
2, 2, 2… to completion, then
3, 3, 3…, and so forth.
See CRBasic example Measuring
VoltSE() at 2000 Hz
7.9.14.1 Measurements from 1 to 100 Hz
Assuming a minimal CRBasic program, measurement rates between 1 and 100 Hz
are determined by the Interval and Units parameters in the Scan() / NextScan
instruction pair. The following program executes VoltSE() at 1 Hz with a 100%
duty cycle.
CRBasic Example 46.
Measuring VoltSE() at 1 Hz
PipeLineMode'<<<<Pipeline mode ensures precise timing of measurements.
Public FastSE
DataTable(FastSETable,1,-1)
Sample(1,FastSE(),FP2)
EndTable
230
Section 7. Installation
BeginProg
Scan(1,Sec,0,0)'<<<<Measurement rate is determined by Interval and Units
VoltSe(FastSE(),1,mV2_5,1,False,100, 250,1.0,0)
CallTable FastSETable
NextScan
EndProg
By modifying the Interval, Units, and Buffers arguments, VoltSE() can be executed at 100 Hz at
100% duty cycle. The following program measures 16 analog-input terminals at 100 Hz.
CRBasic Example 47.
Measuring VoltSE() at 100 Hz
PipeLineMode'<<<<Pipeline mode ensures precise timing of measurements.
Public FastSE(16)
DataTable(FastSETable,1,-1)
Sample(16,FastSE(),FP2)
EndTable
BeginProg
Scan(10,mSec,10,0)'<<<<Measurement rate is determined by Interval, Units, and Buffers
VoltSe(FastSE(),1,mV2_5,1,False,100, 250,1.0,0)
CallTable FastSETable
NextScan
EndProg
7.9.14.2 Measurement Rate: 101 to 600 Hz
To measure at rates between 100 and 600 Hz, the SubScan() / NextSubScan
instruction pair is added. Measurements over 100 Hz do not have 100% duty
cycle, but are accomplished through measurement bursts. Each burst lasts for
some fraction of the scan interval. During the remainder of the scan interval, the
CR1000 processor catches up on overhead tasks and processes data stored in the
buffers. For example, the CR1000 can be programmed to measure VoltSE() on
eight sequential inputs at 200 Hz with a 95% duty cycle as demonstrated in the
following example:
CRBasic Example 48.
Measuring VoltSE() at Ϯ00 Hz
PipeLineMode'<<<<Pipeline mode ensures precise timing of measurements.
Public BurstSE(8)
DataTable(BurstSETable,1,-1)
Sample(8,BurstSE(),FP2)
EndTable
231
Section 7. Installation
BeginProg
Scan(1,Sec,10,0)'<<<<Buffers added
SubScan(5,mSec,190)'<<<<Interval, Units, and Count determine speed and number of measurements
VoltSe(BurstSE(),8,mV2_5,1,False,100,250,1.0,0)
CallTable BurstSETable
NextSubScan
NextScan
EndProg
Many variations of this basic code can be programmed to achieve other burst rates and duty
cycles.
The SubScan() / NextSubScan instruction pair introduce additional complexities.
The SubScan() / NextSubScan Details (p. 231), introduces some of these. Caution
dictates that a specific configuration be thoroughly tested before deployment.
Generally, faster rates require measurement of fewer inputs. When testing a
program, monitoring the SkippedScan (p. 628), BuffDepth (p. 612), and
MaxBuffDepth (p. 620) registers in the CR1000 Status table may give insight into
the use of buffer resources. Bear in mind that when the number of Scan() /
NextScan buffers is exceeded, a skipped scan, and so a missed-data event, will
occur.
7.9.14.2.1
Measurements from 101 to 600 Hz 2
x
x
x
x
The number of Counts (loops) of a sub-scan is limited to 65535
Sub-scans exist only within the Scan() / NextScan structure with the Scan()
interval set large enough to allow a sub-scan to run to completion of its
counts.
Sub-scan interval (i) multiplied by the number of sub-scans (n) equals a
measure time fraction (MT1), a part of "measure time", which measure time is
represented in the MeasureTime register in table Status Table Fields and
Descriptions (p. 603). The EndScan instruction occupies an additional 100 μs
of measurHWLPHVRWKHLQWHUYDORIWKHPDLQVFDQKDVWREH•—VSOXV
measure time outside the SubScan() / EndSubScan construct, plus the time
sub-scans consume.
Because the task sequencer controls sub-scans, it is not finished until all subscans and any following tasks are complete. Therefore, processing does not
start until sub-scans are complete and the task sequencer has set the delay for
the start of the next main scan. So, one Scan() / NextScan buffer holds all
the raw measurements inside (and outside) the sub-scan; that is, all the
measurements made in a single main scan. For example, one execution of the
following code sequence stores 30000 measurements in one buffer:
Scan(40,Sec,3,0) 'Scan(interval, units, buffers, count)
SubScan(2,mSec,10000)
VoltSe(Measurement(),3,mV5000,1,False,150,250,1.0,0)
CallTable All4
NextSubScan
NextScan
Note Measure time in the previous code is 300 μs + 19 ms, so a Scan() interval
less than 20 ms will flag a compile error.
x
232
Sub scans have the advantage of going at a rate faster than 100 Hz. But
measurements that can run at an integral 100 Hz have an advantage as
Section 7. Installation
x
follows: since all sub-scans have to complete before the task sequencer can
set the delay for the main scan, processing is delayed until this point (20 ms
in the above example). So more memory is required for the raw buffer space
for the sub-scan mode to run at the same speed as the non-sub-scan mode,
and there will be more delay before all the processing is complete for the
burst. The pipeline (the raw buffer) has to fill further before processing can
start.
One more way to view sub-scans is that they are a convenient (and only) way
to put a loop around a set of measurements. SubScan() / NextSubScan
specifies a timed loop for so many times around a set of measurements that
can be driven by the task sequencer.
7.9.14.3 Measurement Rate: 601 to 2000 Hz
To measure at rates greater than 600 Hz, VoltSE() is switched into burst mode by
placing a dash (-) before argument in SEChan parameter argument and placing
alternate arguments in other parameters. Alternate arguments are described in the
table Parameters for Analog Burst Mode (p. 234). In burst mode, VoltSE() dwells
on a single channel and measures it at rates up to 2000 Hz, as demonstrated in the
CRBasic example Measuring VoltSE() at 2000 Hz. The example program has an
86% duty cycle. That is, it makes measurements over only the leading 86% of the
scan. Note that burst mode places all measurements for a given burst in a single
variable array and stores the array in a single (but very long!) record in the data
table. The exact sampling interval is calculated as,
Tsample = 1.085069 * INT((SettleUSEC / 1.085069) + 0.5
where SettleUSEC is the sample interval (μs) entered in the SettlingTime
parameter of the analog input instruction.
CRBasic Example 49.
Measuring VoltSE() at Ϯ000 Hz
PipeLineMode'<<<<Pipeline mode ensures precise timing of measurements.
Public BurstSE(1735)
DataTable(BurstSETable,1,-1)
Sample(1735,BurstSE(),FP2)
EndTable
BeginProg
Scan(1,Sec,10,0)
'Measurement speed and count are set within VoltSE()
VoltSe(BurstSE(),1735,mV2_5,-1,False,500,0,1.0,0)
CallTable BurstSETable
NextScan
EndProg
Many variations of the burst program are possible. Multiple inputs can be measured, but one
burst is completed before the next begins. Caution dictates that a specific configuration be
thoroughly tested before deployment.
233
Section 7. Installation
200
Table 34. Parameters for Analog Burst Mode (601 to 2000 Hz)
CRBasic
Analog
Voltage
Description when in Burst Mode
Input
Parameters
A variable array dimensioned to store all measurements from one input. For
example, the command,
Destination
Dim FastTemp(500)
dimensions array FastTemp() to store 500 measurements (one second of data
at 500 Hz, one-half second of data at 1000 Hz, etc.)
The dimension can be any integer from 1 to 65535.
Repetitions
The number of measurements to make on one input. This number usually
equals the number of elements dimensioned in the Destination array.
Valid arguments range from 1 to 65535.
Voltage Range
The analog input voltage range to be used during measurements. No change
from standard measurement mode. Any valid voltage range can be used.
However, ranges appended with 'C' cause measurements to be slower than
other ranges.
Single-Ended
Channel
The single-ended analog input terminal number preceded by a dash (-). Valid
arguments range from -1 to -16.
Differential
Channel
The differential analog input terminal number preceded by a dash (-). Valid
arguments range from -1 to -8.
Measure Offset
No change from standard measurement mode. False allows for faster
measurements.
Measurements
per Excitation
Must equal the value entered in Repetitions
Reverse Ex
No change from standard measurement mode. For fastest rate, set to False.
Rev Diff
No change from standard measurement mode. For fastest rate, set to False.
Sample interval in μs. This argument determines the measurement rate.
500 μs interval = 2000 Hz rate
Settling Time
750 μs interval = 1333.33 Hz rate
Integ
Ignored if set to an integer. _50Hz and _60Hz are valid for AC rejection but
are seldom used in burst applications.
Multiplier
No change from standard measurement mode. Enter the proper multiplier.
This is the slope of the linear equation that equates output voltage to the
measured phenomena. Any number greater or less than 0 is valid.
Offset
No change from standard measurement mode. Enter the proper offset. This is
the Y intercept of the linear equation that equates output voltage to the
measured phenomena.
7.9.15 Measurement: PRT
PRTs (platinum resistance thermometers) are high-accuracy resistive devices used
in measuring temperature.
234
Section 7. Installation
7.9.15.1 Measuring PT100s (100
PRTs)
37Vȍ357VDUHUHDGLO\DYDLODEOH7KH&5FDQPHDVXUH37VLQ
several configurations, each with its own advantages.
7.9.15.1.1
Self-Heating and Resolution
PRT measurements present a dichotomy. Excitation voltage should be maximized
to maximize the measurement resolution. Conversely, excitation voltage should
be minimized to minimize self-heating of the PRT.
,IWKHYROWDJHGURSDFURVVWKH357LV”P9VHOI-heating should be less than
0.001°C in still air. To maximize measurement resolution, optimize the excitation
voltage (Vx) such that the voltage drop spans, but does not exceed, the voltage
input range.
7.9.15.1.2
PRT Calculation Standards
Two CRBasic instructions are available to facilitate PRT measurements.
PRT() — an obsolete instruction. It calculates temperature from RTD
resistance using DIN standard 43760. It is superseded in probably all cases
by PRTCalc().
PRTCalc() — calculates temperature from RTD resistance according to one
of several supported standards. PRTCalc() supersedes PRT() in probably all
cases.
For industrial grade RTDs, the relationship between temperature and resistance is
characterized by the Callendar-Van Dusen (CVD) equation. Coefficients for
different sensor types are given in published standards or by the manufacturers for
non-standard types. Measured temperatures are compared against the ITS-90
scale, a temperature instrumentation-calibration standard.
PRTCalc() follows the principles and equations given in the US ASTM E1137-04
standard for conversion of resistance to temperature. For temperature range 0 to
650 °C, a direct solution to the CVD equation results in errors < ±0.0005 °C
(caused by rounding errors in CR1000 math). For the range of –200 to 0 °C, a
fourth-order polynomial is used to convert resistance to temperature resulting in
errors of < ±0.003 °C.
These errors are only the errors in approximating the relationships between
temperature and resistance given in the relevant standards. The CVD equations
and the tables published from them are only an approximation to the true linearity
of an RTD, but are deemed adequate for industrial use. Errors in that
approximation can be several hundredths of a degree Celsius at different points in
the temperature range and vary from sensor to sensor. In addition, individual
sensors have errors relative to the standard, which can be up to ±0.3 °C at 0 °C
with increasing errors away from 0 °C, depending on the grade of sensor. Highest
accuracy is usually achieved by calibrating individual sensors over the range of
use and applying corrections to the RS/RO value input to the PRTCalc()
instruction (by using the calibrated value of RO) and the multiplier and offset
parameters.
235
Section 7. Installation
Refer to CRBasic Editor Help for specific PRTCalc() parameter entries. The
following information is presented as detail beyond what is available in CRBasic
Editor Help.
The general form of the Callendar-Van Dusen (CVD) equation is shown in the
following equations.
When R/R0 < 1 (K = R/R0 – 1):
T = g * K^4 + h * K^3 + I * K^2 + j * K
When R/R0 >= 1:
T = (SQRT(d * (R/R0) + e) -a) / f
Depending on the code entered for parameter Type, which specifies the platinumresistance sensor type, coefficients are assigned values according to the following
tables.
Note Coefficients are rounded to the seventh significant digit to match the
CR1000 math resolution.
Alpha is defined as:
D = (R100 – R0‡50)
D = (R100 / R0 – 1) / 100
where R100 and R0 are the resistances of the PRT at 100 °C and 0 °C, respectively.
Table 35. PRTCalc() Type-Code-1 Sensor
IEC 60751:2008 (IEC 751), alpha = 0.00385. Now internationally adopted and written into
standards ASTM E1137-04, JIS 1604:1997, EN 60751 and others. This type code is also used
with probes compliant with older standards DIN43760, BS1904, and others. (Reference: IEC
60751. ASTM E1137)
236
Constant
Coefficient
a
3.9083000E-03
d
-2.3100000E-06
e
1.7584810E-05
f
-1.1550000E-06
g
1.7909000E+00
h
-2.9236300E+00
i
9.1455000E+00
j
2.5581900E+02
Section 7. Installation
Table 36. PRTCalc() Type-Code-2 Sensor
US Industrial Standard, alpha = 0.00392 (Reference: Logan Enterprises)
Constant
Coefficient
a
3.9786300E-03
d
-2.3452400E-06
e
1.8174740E-05
f
-1.1726200E-06
g
1.7043690E+00
h
-2.7795010E+00
i
8.8078440E+00
j
2.5129740E+02
Table 37. PRTCalc() Type-Code-3 Sensor
US Industrial Standard, alpha = 0.00391 (Reference: OMIL R84 (2003))
Constant
Coefficient
a
3.9690000E-03
d
-2.3364000E-06
e
1.8089360E-05
f
-1.1682000E-06
g
1.7010560E+00
h
-2.6953500E+00
i
8.8564290E+00
j
2.5190880E+02
Table 38. PRTCalc() Type-Code-4 Sensor
Old Japanese Standard, alpha = 0.003916 (Reference: JIS C 1604:1981, National Instruments)
Constant
Coefficient
a
3.9739000E-03
d
-2.3480000E-06
e
1.8139880E-05
f
-1.1740000E-06
g
1.7297410E+00
h
-2.8905090E+00
i
8.8326690E+00
j
2.5159480E+02
237
Section 7. Installation
Table 39. PRTCalc() Type-Code-5 Sensor
Honeywell Industrial Sensors, alpha = 0.00375 (Reference: Honeywell)
Constant
Coefficient
a
3.8100000E-03
d
-2.4080000E-06
e
1.6924100E-05
f
-1.2040000E-06
g
2.1790930E+00
h
-5.4315860E+00
i
9.9196550E+00
j
2.6238290E+02
Table 40. PRTCalc() Type-Code-6 Sensor
Standard ITS-90 SPRT, alpha = 0.003926 (Reference: Minco / Instrunet)
Constant
Coefficient
a
3.9848000E-03
d
-2.3480000E-06
e
1.8226630E-05
f
-1.1740000E-06
g
1.6319630E+00
h
-2.4709290E+00
i
8.8283240E+00
j
2.5091300E+02
7.9.15.2 PT100 in Four-Wire Half-Bridge
Example shows:
x
x
How to measure a PRT in a four-wire half-bridge configuration
How to compensate for long leads
Advantages:
x
High accuracy with long leads
Example PRT specifications:
x
Alpha = 0.00385 (PRT Type 1)
A four-wire half-bridge, measured with BrHalf4W(), is the best configuration for
accuracy in cases where the PRT is separated from bridge resistors by a lead
238
Section 7. Installation
length having more than a few thousandths of an ohm resistance. In this example,
the measurement range is –10° to 40 °C. The length of the cable from the
CR1000 and the bridge resistors to the PRT is 500 feet.
Figure PT100 in Four-Wire Half-Bridge (p. 240) shows the circuit used to measure a
ȍ3577KHNȍUHVLVWRUDOORZVWKHXVHRIDKLJKH[FLWDWLRQYROWDJHDQGD
low input range. This ensures that noise in the excitation does not have an effect
on signal noise. Because the fixed resistor (Rf) and the PRT (RS) have
approximately the same resistance, the differential measurement of the voltage
drop across the PRT can be made on the same range as the differential
measurement of the voltage drop across Rf. The use of the same range eliminates
range translation errors that can arise from the 0.01% tolerance of the range
translation resistors internal to the CR1000.
7.9.15.2.1
Calculating the Excitation Voltage
The voltage drop across the PRT is equal to VX multiplied by the ratio of RS to the
total resistance, and is greatest when RS is greatest (RS ȍDWƒ&7R
find the maximum excitation voltage that can be used on the ±25 mV input range,
assume V2 is equal to 25 mV and use Ohm's Law to solve for the resulting
current, I.
I = 25 mV/RS = 25 mV/115. 54 ohms = 0.216 mA
Next solve for VX:
VX = I*(R1 + RS + Rf) = 2.21 V
If the actual resistances were the nominal values, the CR1000 would not over
range with VX = 2.2 V. However, to allow for the tolerance in actual resistors, set
VX equal WR9HJLIWKHNȍUHVLVWRULVORZLH
RS/(R1+RS+Rf)=115.54 / 9715.54, and VX must be 2.102 V to keep VS less than
25 mV).
7.9.15.2.2
Calculating the BrHalf4W() Multiplier
The result of BrHalf4W() is equivalent to RS/Rf.
X = RS/Rf
PRTCalc() computes the temperature (°C) for a DIN 43760 standard PRT from
the ratio of the PRT resistance to its resistance at 0 °C (RS/R0). Thus, a multiplier
of Rf/R0 is used in BrHalf4W() to obtain the desired intermediate, RS/R0 (=RS/Rf
‡5f/R0). If RS and R0 were eacKH[DFWO\ȍWKHPXOWLSOLHUZRXOGEH
However, neither resistance is likely to be exact. The correct multiplier is found
by connecting the PRT to the CR1000 and entering BrHalf4W() with a multiplier
of 1. The PRT is then placed in an ice bath (0 °C), and the result of the bridge
measurement is read. The reading is RS/Rf, which is equal to R0/Rf since RS=R0
at 0 °C. The correct value of the multiplier, Rf/R0, is the reciprocal of this
reading. The initial reading assumed for this example was 0.9890. The correct
multiplier is: Rf/R0 = 1/0.9890 = 1.0111.
239
Section 7. Installation
7.9.15.2.3
Choosing Rf
7KHIL[HGȍUHVLVWRUPXVWEHWKHUPDOO\VWDEOH,WVSUHFLVLRQLVQRWLPSRUWDQW
because the exact resistance is incorporated, along with that of the PRT, into the
calibrated multiplier. The 10 ppm/°C temperature coefficient of the fixed resistor
will limit the error due to its change in resistance with temperature to less than
0.15 °C over the –10° to 40 °C temperature range. Because the measurement is
ratiometric (RS/RfWKHSURSHUWLHVRIWKHNȍUHVLVWRUGRQRWDIIHFWWKHUHVXOW
A terminal-input module (TIM) can be used to complete the circuit shown in
figure PT100 in Four-Wire Half-Bridge (p. 240). Refer to the appendix Signal
Conditioners (p. 647) for information concerning available TIM modules.
Figure 63. PT100 in Four-Wire Half-Bridge
CRBasic Example ϱ0.
PT100 in Four-Wire Half-Bridge
'This program example demonstrates the measurement of a 100-ohm PRT using a four-wire half
'bridge. See FIGURE. PT100 in Four-Wire Half-Bridge (p. 240) for the wiring diagram
Public Rs_Ro
Public Deg_C
BeginProg
Scan(1,Sec,0,0)
'BrHalf4W(Dest,Reps,Range1,Range2,DiffChan1,ExChan,MPS,Ex_mV,RevEx,RevDiff,
' Settling, Integration,Mult,Offset)
BrHalf4W(Rs_Ro,1,mV25,mV25,1,Vx1,1,2200,True,True,0,250,1.0111,0)
'PRTCalc(Destination,Reps,Source,PRTType,Mult,Offset)
PRTCalc(Deg_C,1,Rs_Ro,1,1.0,0) 'PRTType sets alpha
NextScan
EndProg
240
Section 7. Installation
7.9.15.3 PT100 in Three-Wire Half Bridge
Example shows:
x
How to measure a PRT in a three-wire half-bridge configuration.
Advantages:
x
Uses half as many terminals configured for analog input as four-wire halfbridge.
Disadvantages:
x
May not be as accurate as four-wire half-bridge.
Example PRT specifications:
x
Alpha = 0.00385 (PRTType 1)
The temperature measurement requirements in this example are the same as in
PT100 in Four-Wire Half-Bridge (p. 238). In this case, a three-wire half-bridge and
CRBasic instruction BRHalf3W() are used to measure the resistance of the PRT.
The diagram of the PRT circuit is shown in figure PT100 in Three-Wire HalfBridge (p. 242).
As in section PT100 in Four-Wire Half-Bridge (p. 238), the excitation voltage is
calculated to be the maximum possible, yet allows the measurement to be made
RQWKH“P9LQSXWUDQJH7KHNȍUHVLVWRUKDVDWROHUDQFHRI“WKXVWKH
ORZHVWUHVLVWDQFHWRH[SHFWIURPLWLVNȍ6ROYHIRU9X (the maximum
excitation voltage) to keep the voltage drop across the PRT less than 25 mV:
0.025 V > (VX * 115.54)/(9900+115.54)
VX < 2.16 V
The excitation voltage used is 2.2 V.
The multiplier used in BRHalf3W() is determined in the same manner as in
PT100 in Four-Wire Half-Bridge (p. 238). In this example, the multiplier (Rf/R0) is
assumed to be 100.93.
The three-wire half-bridge compensates for lead wire resistance by assuming that
the resistance of wire A is the same as the resistance of wire B. The maximum
difference expected in wire resistance is 2%, but is more likely to be on the order
of 1%. The resistance of RS calculated with BRHalf3W() is actually RS plus the
difference in resistance of wires A and B. The average resistance of 22 AWG
wire is 16.5 ohms per 1000 feet, which would give each 500 foot lead wire a
nominal resistance of 8.3 ohms. Two percent of 8.3 ohms is 0.17 ohms.
Assuming that the greater resistance is in wire B, the resistance measured for the
PRT (R0 = 100 ohms) in the ice bath would be 100.17 ohms, and the resistance at
40°C would be 115.71. The measured ratio RS/R0 is 1.1551; the actual ratio is
115.54/100 = 1.1554. The temperature computed by PRTCalc() from the
measured ratio will be about 0.1°C lower than the actual temperature of the PRT.
This source of error does not exist in the example in PT100 in Four-Wire HalfBridge (p. 238) because a four-wire half-bridge is used to measure PRT resistance.
241
Section 7. Installation
A terminal input module can be used to complete the circuit in figure PT100 in
Three-Wire Half-Bridge (p. 242). Refer to the appendix Signal Conditioners (p. 647)
for information concerning available TIM modules.
Figure 64. PT100 in Three-Wire Half-Bridge
CRBasic Example ϱ1.
PT100 in Three-wire Half-bridge
'This program example demonstrates the measurement of a 100-ohm PRT using a three-wire half
'bridge. See FIGURE. PT100 in Three-Wire Half-Bridge (p. 242) for wiring diagram.
Public Rs_Ro
Public Deg_C
BeginProg
Scan(1,Sec,0,0)
'BrHalf3W(Dest,Reps,Range1,SEChan,ExChan,MPE,Ex_mV,True,0,250,100.93,0)
BrHalf3W(Rs_Ro,1,mV25,1,Vx1,1,2200,True,0,250,100.93,0)
'PRTCalc(Destination,Reps,Source,PRTType,Mult,Offset)
PRTCalc(Deg_C,1,Rs_Ro,1,1.0,0)
NextScan
EndProg
7.9.15.4 PT100 in Four-Wire Full-Bridge
Example shows:
x
How to measure a PRT in a four-wire full-bridge
Advantages:
x
Uses half as many terminals configured for analog input as four-wire halfbridge.
Example PRT Specifications:
x
D = 0.00392 (PRTType 2)
This example measures a 100 ohm PRT in a four-wire full-bridge, as shown in
figure PT100 in Four-Wire Full-Bridge (p. 244), using CRBasic instruction
242
Section 7. Installation
BRFull(). In this example, the PRT is in a constant-temperature bath and the
measurement is to be used as the input for a control algorithm.
As described in table Resistive-Bridge Circuits with Voltage Excitation (p. 338), the
result of BRFull() is X,
X = 1000 VS/VX
where,
VS = measured bridge-output voltage
VX = excitation voltage
or,
X = 1000 (RS/(RS+R1) – R3/(R2+R3)).
With reference to figure PT100 in Four-Wire Full-Bridge (p. 244), the resistance of
the PRT (RS) is calculated as:
RS = R1
‡
X' / (1-X')
where
X' = X / 1000 + R3/(R2+R3)
Thus, to obtain the value RS/R0, (R0 = RS @ 0 °C) for the temperature calculating
instruction PRTCalc(), the multiplier and offset used in BRFull() are 0.001 and
R3/(R2+R3), respectively. The multiplier (Rf) used in the bridge transform
algorithm (X = Rf (X/(X-1)) to obtain RS/R0 is R1/R0 or (5000/100 = 50).
The application requires control of the temperature bath at 50 °C with as little
variation as possible. High resolution is desired so the control algorithm will
respond to very small changes in temperature. The highest resolution is obtained
when the temperature range results in a signal (VS) range that fills the
measurement range selected in BRFull(). The full-bridge configuration allows
the bridge to be balanced (VS = 0 V) at or near the control temperature. Thus, the
output voltage can go both positive and negative as the bath temperature changes,
allowing the full use of the measurement range.
7KHUHVLVWDQFHRIWKH357LVDSSUR[LPDWHO\ȍDWƒ&7KHȍIL[HG
resistor balances the bridge at approximately 51 °C. The output voltage is:
VS = VX ‡ [RS/(RS+R1) – R3/(R2+R3)]
= VX ‡ [RS/(RS+5000) – 0.023438]
The temperature range to be covered is 50 °C ±10 °C. At 40 °C, RS is
DSSUR[LPDWHO\ȍRU
VS = –802.24E–6 VX.
Even with an excitation voltage (VX) equal to 2500 mV, VS can be measured on
WKH“BP9VFDOHƒ&ȍ–P9ƒ&ȍP9
There is a change of approximately 2 mV from the output at 40°C to the output at
51 °C, or 181 μV / °C. With a resolution of 0.33 μV on the ±2_5 mV range, this
means that the temperature resolution is 0.0009 °C.
243
Section 7. Installation
The ±5 ppm per °C temperature coefficient of the fixed resistors was chosen
because the ±0.01% accuracy tolerance would hold over the desired temperature
range.
Figure 65. PT100 in Four-Wire Full-Bridge
CRBasic Example ϱϮ.
PT100 in Four-Wire Full-Bridge
'This program example demonstrates the measurement of a 100-ohm four-wire full bridge. See
'FIGURE. PT100 in Four-Wire Full-Bridge (p. 244) for wiring diagram.
Public BrFullOut
Public Rs_Ro
Public Deg_C
BeginProg
Scan(1,Sec,0,0)
'BrFull(Dst,Reps,Range,DfChan,Vx1,MPS,Ex,RevEx,RevDf,Settle,Integ,Mult,Offset)
BrFull(BrFullOut,1,mV25,1,Vx1,1,2500,True,True,0,250,.001,.02344)
'BrTrans = Rf*(X/(1-X))
Rs_Ro = 50 * (BrFullOut/(1 - BrFullOut))
'PRTCalc(Destination,Reps,Source,PRTType,Mult,Offset)
PRTCalc(Deg_C,1,Rs_Ro,2,1.0,0)
NextScan
EndProg
7.9.16 PLC Control — Details
Related Topics:
‡PLC Control — Overview (p. 74)
‡PLC Control — Details (p. 244)
‡PLC Control Modules — Overview (p. 368)
‡PLC Control Modules — Lists (p. 648)
‡PLC Control — Instructions (p. 562)
‡6ZLWFKHG9ROWDJH2XWSXW— Specifications
‡6ZLWFKHG9ROWDJH2XWSXW— Overview
‡Switched Voltage Output — Details (p. 103)
244
Section 7. Installation
This section is slated for expansion. Below are a few tips.
x
x
x
x
Short Cut programming wizard has provisions for simple on/off control.
PID control can be done with the CR1000. Ask a Campbell Scientific
application engineer for more information.
When controlling a PID algorithm, a delay between processing (algorithm
input) and the control (algorithm output) is not usually desirable. A delay
will not occur in either sequential mode (p. 527) or pipeline mode (p. 523),
assuming an appropriately fast scan interval is programmed, and the program
is not skipping scans. In sequential mode, if some task occurs that pushes
processing time outside the scan interval, skipped scans will occur and the
PID control may fail. In pipeline mode, with an appropriately sized scan
buffer, no skipped scans will occur. However, the PID control may fail as the
processing instructions work through the scan buffer.
To avoid these potential problems, bracket the processing instructions in the
CRBasic program with ProcHiPri and EndProcHiPri. Processing
instructions between these instructions are given the same high priority as
measurement instructions and do not slip into the scan buffer if processing
time is increased. ProcHiPri and EndProcHiPri may not be selectable in
CRBasic Editor. You can type them in anyway, and the compiler will
recognize them.
7.9.17 Serial I/O: Capturing Serial Data
The CR1000 communicates with smart sensors that deliver measurement data
through serial data protocols.
Read More See Telecommunications and Data Retrieval (p. 391) for background
on CR1000 serial communications.
7.9.17.1 Introduction
Serial denotes transmission of bits (1s and 0s) sequentially, or "serially." A byte
is a packet of sequential bits. RS-232 and TTL standards use bytes containing
eight bits each. Consider an instrument that transmits the byte "11001010" to the
CR1000. The instrument does this by translating "11001010" into a series of
higher and lower voltages, which it transmits to the CR1000. The CR1000
receives and reconstructs these voltage levels as "11001010." Because an RS-232
or TTL standard is adhered to by both the instrument and the CR1000, the byte
successfully passes between them.
If the byte is displayed on a terminal as it was received, it will appear as an ASCII
/ ANSI character or control code. Table ASCII / ANSI Equivalents (p. 245) shows a
sample of ASCII / ANSI character and code equivalents.
Table 41. ASCII / ANSI Equivalents
Byte
Received
ASCII
Character
Displayed
Decimal
ASCII
Code
Hex
ASCII
Code
00110010
2
50
32
1100010
b
98
62
00101011
+
43
2b
245
Section 7. Installation
Table 41. ASCII / ANSI Equivalents
Byte
Received
ASCII
Character
Displayed
Decimal
ASCII
Code
Hex
ASCII
Code
00001101
cr
13
d
00000001
ſ
1
1
Read More See the appendix ASCII / ANSI Table (p. 637) for a complete list of
ASCII / ANSI codes and their binary and hex equivalents.
The face value of the byte, however, is not what is usually of interest. The
manufacturer of the instrument must specify what information in the byte is of
interest. For instance, two bytes may be received, one for character 2, the other for
character b. The pair of characters together, "2b", is the hexadecimal code for "+",
"+" being the information of interest. Or, perhaps, the leading bit, the MSB (Most
Significant Bit), on each of two bytes is dropped, the remaining bits combined,
and the resulting "super byte" translated from the remaining bits into a decimal
value. The variety of protocols is limited only by the number of instruments on
the market. For one in-depth example of how bits may be translated into usable
information, see the appendix FP2 Data Format (p. 641).
Note ASCII / ANSI control character ff-form feed (binary 00001100) causes a
terminal screen to clear. This can be frustrating for a developer who prefers to see
information on a screen, rather than a blank screen. Some third party terminal
emulator programs, such as Procomm, are useful tools in serial I/O development
since they handle this and other idiosyncrasies of serial communication.
When a standardized serial protocol is supported by the CR1000, such as
PakBus® or Modbus, translation of bytes is relatively easy and transparent.
However, when bytes require specialized translation, specialized code is required
in the CRBasic program, and development time can extend into several hours or
days.
7.9.17.2 I/O Ports
The CR1000 supports two-way serial communication with other instruments
through ports listed in table CR1000 Serial Ports (p. 247). A serial device will often
be supplied with a nine-pin D-type connector serial port. Check the manufacture's
pinout for specific information. In many cases, the standard nine-pin RS-232
scheme is used. If that is the case then,
Connect sensor RX (receive, pin 2) to a U or C terminal configured for Tx (C1,
C3, C5, C7).
x
x
Connect sensor TX (transmit, pin 3) to a U or C terminal configured for Rx
(C2, C4, C6, C8)
Connect sensor ground (pin 5) to datalogger ground (G terminal)
Note Rx and Tx lines on nine-pin connectors are sometimes switched by the
manufacturer.
246
Section 7. Installation
Table 42. CR1000 Serial Ports
Serial Port
Voltage Level
Logic
RS-232 (9 pin)
RS-232
Full-duplex asynchronous RS-232
CS I/O (9 pin)
TTL
Full-duplex asynchronous RS-232
COM1 (C1 – C2)
TTL
Full-duplex asynchronous RS-232/TTL
COM2 (C3 – C4)
TTL
Full-duplex asynchronous RS-232/TTL
COM3 (C5 – C6)
TTL
Full-duplex asynchronous RS-232/TTL
COM4 (C7 – C8)
TTL
Full-duplex asynchronous RS-232/TTL
C1
5 Vdc
SDI-12
C3
5 Vdc
SDI-12
C5
5 Vdc
SDI-12
C7
5 Vdc
SDI-12
C1, C2, C3
5 Vdc
SDM (used with Campbell Scientific
peripherals only)
7.9.17.3 Protocols
PakBus is the protocol native to the CR1000 and transparently handles routine
point-to-point and network communications among PCs and Campbell Scientific
dataloggers. Modbus and DNP3 are industry-standard networking SCADA
protocols that optionally operate in the CR1000 with minimal user configuration.
PakBus®, Modbus, and DNP3 operate on the RS-232, CS I/O, and four COM
ports. SDI-12 is a protocol used by some smart sensors that requires minimal
configuration on the CR1000.
Read More See SDI-12 Recording (p. 363), SDI-12 Sensor Support (p. 267), PakBus
Overview (p. 393), DNP3 (p. 408), and Modbus (p. 411).
Many instruments require non-standard protocols to communicate with the
CR1000.
Note If an instrument or sensor optionally supports SDI-12, Modbus, or DNP3,
consider using these protocols before programming a custom protocol. These
higher-level protocols are standardized among many manufacturers and are easy
to use, relative to a custom protocol. SDI-12, Modbus, and DNP3 also support
addressing systems that allow multiplexing of several sensors on a single
communication port, which makes for more efficient use of resources.
7.9.17.4 Glossary of Serial I/O Terms
Term. asynchronous
The transmission of data between a transmitting and a receiving device
occurs as a series of zeros and ones. For the data to be "read" correctly, the
receiving device must begin reading at the proper point in the series. In
asynchronous communication, this coordination is accomplished by having
247
Section 7. Installation
each character surrounded by one or more start and stop bits which designate
the beginning and ending points of the information (see synchronous (p. 530) ).
Indicates the sending and receiving devices are not synchronized using a
clock signal.
Term. baud rate
The rate at which data are transmitted.
Term. big endian
"Big end first." Placing the most significant integer at the beginning of a
numeric word, reading left to right. The processor in the CR1000 is MSB, or
puts the most significant integer first. See the appendix Endianness (p. 643).
Term. cr
Carriage return
Term. data bits
Number of bits used to describe the data, and fit between the start and stop
bits. Sensors typically use 7 or 8 data bits.
Term. duplex
A serial communication protocol. Serial communications can be simplex,
half-duplex, or full-duplex.
Reading list: simplex (p. 528), duplex (p. 248), half-duplex (p. 517), and full-duplex
(p. 516).
Term. lf
Line feed. Often associated with carriage return (<cr>). <cr><lf>.
Term. little endian
"Little end first." Placing the most significant integer at the end of a numeric
word, reading left to right. The processor in the CR1000 is MSB, or puts the
most significant integer first. See the appendix Endianness (p. 643).
Term. LSB
Least significant bit (the trailing bit). See the appendix Endianness (p. 643).
Term. marks and spaces
RS-232 signal levels are inverted logic compared to TTL. The different levels
are called marks and spaces. When referenced to signal ground, the valid RS232 voltage level for a mark is –3 to –25, and for a space is +3 to +25 with –3
to + 3 defined as the transition range that contains no information. A mark is
a logic 1 and negative voltage. A space is a logic 0 and positive voltage.
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Section 7. Installation
Term. MSB
Most significant bit (the leading bit). See the appendix Endianness (p. 643).
Term. RS-232C
Refers to the standard used to define the hardware signals and voltage levels.
The CR1000 supports several options of serial logic and voltage levels
including RS-232 logic at TTL levels and TTL logic at TTL levels.
Term. RX
Receive
Term. SP
Space
Term. start bit
Is the bit used to indicate the beginning of data.
Term. stop bit
Is the end of the data bits. The stop bit can be 1, 1.5 or 2.
Term. TX
Transmit
7.9.17.5 Serial I/O CRBasic Programming
To transmit or receive RS-232 or TTL signals, a serial port (see table CR1000
Serial Ports (p. 247)) must be opened and configured through CRBasic with the
SerialOpen() instruction. The SerialClose() instruction can be used to close the
serial port. Below is practical advice regarding the use of SerialOpen() and
SerialClose(). Program CRBasic example Receiving an RS-232 String (p. 254)
shows the use of SerialOpen(). Consult CRBasic Editor Help for more
information.
SerialOpen(COMPort,BaudRate,Format,TXDelay,BufferSize)
x
x
x
x
COMPort — Refer to CRBasic Editor Help for a complete list of COM ports
available for use by SerialOpen().
BaudRate — Baud rate mismatch is frequently a problem when developing a
new application. Check for matching baud rates. Some developers prefer to
use a fixed baud rate during initial development. When set to -nnnn (where
nnnn is the baud rate) or 0, auto baud-rate detect is enabled. Autobaud is
useful when using the CS I/O and RS-232 ports since it allows ports to be
simultaneously used for sensor and PC telecommunications.
Format — Determines data type and if PakBus® communications can occur
on the COM port. If the port is expected to read sensor data and support
normal PakBus® telemetry operations, use an auto-baud rate argument (0 or nnnn) and ensure this option supports PakBus® in the specific application.
BufferSize — The buffer holds received data until it is removed. SerialIn(),
SerialInRecord(), and SerialInBlock() instructions are used to read data
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Section 7. Installation
from the buffer to variables. Once data are in variables, string manipulation
instructions are used to format and parse the data.
SerialClose() must be executed before SerialOpen() can be used again to
reconfigure the same serial port, or before the port can be used to communicate
with a PC.
7.9.17.5.1
Serial I/O Programming Basics
SerialOpen()1
x
x
x
Closes PPP (if active)
Returns TRUE or FALSE when set equal to a Boolean variable
Be aware of buffer size (ring memory)
SerialClose()
x
Examples of when to close
o
o
o
x
Reopen PPP
Finished setting new settings in a Hayes modem
Finished dialing a modem
Returns TRUE or FALSE when set equal to a Boolean variable
SerialFlush()
x
x
Puts the read and write pointers back to the beginning
Returns TRUE or FALSE when set equal to a Boolean variable
SerialIn()1
x
x
x
x
Can wait on the string until it comes in
Timeout is renewed after each character is received
SerialInRecord() tends to obsolete SerialIn().
Buffer-size margin (one extra record + one byte)
SerialInBlock()1
x
x
x
For binary data (perhaps integers, floats, data with NULL characters).
Destination can be of any type.
Buffer-size margin (one extra record + one byte).
SerialOutBlock()1,3
x
x
Binary
Can run in pipeline mode inside the digital measurement task (along with
SDM instructions) if the COMPort parameter is set to a constant such as
COM1, COM2, COM3, or COM4, and the number of bytes is also entered
as a constant.
SerialOut()
x
x
250
Use for ASCII commands and a known response, such as Hayes-modem
commands.
If open, returns the number of bytes sent. If not open, returns 0.
Section 7. Installation
SerialInRecord()2
x
x
x
x
x
1
2
3
7.9.17.5.2
Can run in pipeline mode inside the digital measurement task (along with
SDM instructions) if the COMPort parameter is set to a constant argument
such as COM1, COM2, COM3, or COM4, and the number of bytes is also
entered as a constant.
Simplifies synchronization with one way.
Simplifies working with protocols that send a "record" of data with known
start and/or end characters, or a fixed number of records in response to a poll
command.
If a start and end word is not present, then a time gap is the only remaining
separator of records. Using COM1, COM2, COM3, or COM4
coincidentally detects a time gap of >100 bits if the records are less than 256
bytes.
Buffer size margin (one extra record + one byte).
Processing instructions
Measurement instruction in the pipeline mode
Measurement instruction if expression evaluates to a constant
Serial I/O Input Programming Basics
Applications with the purpose of receiving data from another device usually
include the following procedures. Other procedures may be required depending on
the application.
1. Know what the sensor supports and exactly what the data are. Most sensors
work well with TTL voltage levels and RS-232 logic. Some things to
consider:
o
o
o
o
o
o
o
o
o
Become thoroughly familiar with the data to be captured.
Can the sensor be polled?
Does the sensor send data on its own schedule?
Are there markers at the beginning or end of data? Markers are very
useful for identifying a variable length record.
Does the record have a delimiter character such as a comma, space, or
tab? Delimiters are useful for parsing the received serial string into
usable numbers.
Will the sensor be sending multiple data strings? Multiple strings usually
require filtering before parsing.
How fast will data be sent to the CR1000?
Is power consumption critical?
Does the sensor compute a checksum? Which type? A checksum is
useful to test for data corruption.
2. Open a serial port with SerialOpen().
o
Example:
SerialOpen(Com1,9600,0,0,10000)
o
o
o
Designate the correct port in CRBasic.
Correctly wire the device to the CR1000.
Match the port baud rate to the baud rate of the device in CRBasic (use a
fixed baud rate — rather than autobaud — when possible).
251
Section 7. Installation
3. Receive serial data as a string with SerialIn() or SerialInRecord().
Example:
SerialInRecord(Com2,SerialInString,42,0,35,"",01)
o
Declare the string variable large enough to accept the string.
Example:
Public SerialInString As String * 25
o
Observe the input string in the input string variable in a numeric monitor
(p. 521).
Note SerialIn() and SerialInRecord() both receive data. SerialInRecord() is
best for receiving streaming data. SerialIn() is best for receiving discrete
blocks.
4. Parse (split up) the serial string using SplitStr()
o
o
Separates string into numeric and / or string variables.
Example:
SplitStr(InStringSplit,SerialInString,"",2,0)
o
Declare an array to accept the parsed data.
Example:
Public InStringSplit(2) As String
Example:
Public SplitResult(2) As Float
7.9.17.5.3
Serial I/O Output Programming Basics
Applications with the purpose of transmitting data to another device usually
include the following procedures. Other procedures may be required depending on
the application.
1. Open a serial port with SerialOpen() to configure it for communications.
o
o
Parameters are set according to the requirements of the communication
link and the serial device.
Example:
SerialOpen(Com1,9600,0,0,10000)
o
o
o
o
Designate the correct port in CRBasic.
Correctly wire the device to the CR1000.
Match the port baud rate to the baud rate of the device in CRBasic.
Use a fixed baud rate (rather than auto baud) when possible.
2. Build the output string.
o
Example:
SerialOutString = "*" & "27.435" & "," & "56.789" & "#"
o
o
252
Tip — concatenate (add) strings together using & instead of +.
Tip — use CHR() instruction to insert ASCII / ANSI characters into a
string.
Section 7. Installation
3. Output string via the serial port (SerialOut() or SerialOutBlock() command).
o
Example:
SerialOut(Com1,SerialOutString,"",0,100)
o
o
Declare the output string variable large enough to hold the entire
concatenation.
Example:
Public SerialOutString As String * 100
x
7.9.17.5.4
SerialOut() and SerialOutBlock() output the same data, except that
SerialOutBlock() transmits null values while SerialOut() strings are
terminated by a null value.
Serial I/O Translating Bytes
One or more of three principle data formats may end up in the SerialInString()
variable (see examples in Serial Input Programming Basics (p. 251) ). Data may be
combinations or variations of these. The instrument manufacturer must provide
the rules for decoding the data
x
Alpha-numeric — Each digit represents an alpha-numeric value. For
example, R = the letter R, and 2 = decimal 2. This is the easiest protocol to
translate since the encode and translation are identical. Normally, the
CR1000 is programmed to parse (split) the string and place values in
variables.
Example string from humidity, temperature, and pressure sensor:
SerialInString = "RH= 60.5 %RH T= 23.7 °C Tdf= 15.6 °C Td=
15.6 °C a= 13.0 g/m3
x=
11.1 g/kg
Tw= 18.5 °C H2O=
17889 ppmV pw=17.81 hPa pws
29.43 hPa h= 52.3 kJ/kg
dT=
8.1 °C"
x
Hex Pairs — Bytes are translated to hex pairs, consisting of digits 0 to 9 and
letters a to f. Each pair describes a hexadecimal ASCII / ANSI code. Some
codes translate to alpha-numeric values, others to symbols or non-printable
control characters.
Example sting from temperature sensor:
SerialInString = "23 30 31 38 34 0D"
which translates to
#01 84 cr
x
Binary — Bytes are processed on a bit-by-bit basis. Character 0 (Null,
&b00) is a valid part of binary data streams. However, the CR1000 uses Null
terminated strings, so anytime a Null is received, a string is terminated. The
termination is usually premature when reading binary data. To remedy this
problem, use SerialInBlock() or SerialInRecord() when reading binary data.
The input string variable must be an array set As Long data type, for
example:
Dim SerialInString As Long
7.9.17.5.5
Serial I/O Memory Considerations
Several points regarding memory should be considered when receiving and
processing serial data.
253
Section 7. Installation
x
Serial buffer: The serial port buffer, which is declared in SerialOpen(), must
be large enough to hold all data a device will send. The buffer holds the data
for subsequent transfer to variables. Allocate extra memory to the buffer
when needed, but recognize that memory added to the buffer reduces finaldata memory (p. 515).
Note Concerning SerialInRecord() running in pipeline mode with NBytes
(number of bytes) parameter = 0:
For the digital measurement sequence to know how much room to allocate in
Scan() buffers (default of 3), SerialInRecord() allocates the buffer size specified
by SerialOpen() (default 10,000, an overkLOORUGHIDXOW‡ N%RI
buffer space. So, while making sure enough bytes are allocated in SerialOpen()
WKHQXPEHURIE\WHVSHUUHFRUG‡UHFRUGV6FDQDWOHDVWRQHH[WUDE\WH
there is reason not to make the buffer size too large. (Note that if the
NumberOfBytes parameter is non-zero, then SerialInRecord() allocates only this
many bytes instead of the number of bytes specified by SerialOpen()).
x
x
Variable Declarations — Variables used to receive data from the serial
buffer can be declared as Public or Dim. Declaring variables as Dim has the
effect of consuming less telecommunication bandwidth. When public
variables are viewed in software, the entire Public table is transferred at the
update interval. If the Public table is large, telecommunication bandwidth
can be taxed such that other data tables are not collected.
String Declarations — String variables are memory intensive. Determine
how large strings are and declare variables just large enough to hold the
string. If the sensor sends multiple strings at once, consider declaring a single
string variable and read incoming strings one at a time.
The CR1000 adjusts upward the declared size of strings. One byte is always
added to the declared length, which is then increased by up to another three
bytes to make the length divisible by four.
Declared string length, not number of characters, determines the memory
consumed when strings are written to memory. Consequently, large strings
not filled with characters waste significant memory.
7.9.17.5.6
Demonstration Program
CRBasic example Receiving an RS-232 String (p. 254) is provided as an exercise in
serial input / output programming. The example only requires the CR1000 and a
single-wire jumper between COM1 Tx and COM2 Rx. The program simulates a
temperature and relative humidity sensor transmitting RS-232 (simulated data
comes out of COM1 as an alpha-numeric string).
254
Section 7. Installation
CRBasic Example ϱ3.
Receiving an RS-Ϯ3Ϯ String
'This program example demonstrates CR1000 serial I/O features by:
' 1. Simulating a serial sensor
' 2. Transmitting a serial string via COM1 TX.
'The serial string is received at COM2 RX via jumper wire.
'air temperature = 27.435 F, relative humidity = 56.789 %.
Simulated
'Wiring:
'COM1 TX (C1) ----- COM2 RX (C4)
'Serial Out Declarations
Public TempOut As Float
Public RhOut As Float
'Declare a string variable large enough to hold the output string.
Public SerialOutString As String * 25
'Serial In Declarations
'Declare a string variable large enough to hold the input string
Public SerialInString As String * 25
'Declare strings to accept parsed data.
'array can be declared as Float or Long
Public InStringSplit(2) As String
Alias InStringSplit(1) = TempIn
Alias InStringSplit(2) = RhIn
If parsed data are strictly numeric, this
'Main Program
BeginProg
'Simulate temperature and RH sensor
TempOut = 27.435
RhOut = 56.789
'Set simulated temperature to transmit
'Set simulated relative humidity to transmit
Scan(5,Sec, 3, 0)
'Serial Out Code
'Transmits string "*27.435,56.789#" out COM1
SerialOpen(Com1,9600,0,0,10000)
'Open a serial port
'Build the output string
SerialOutString = "*" & TempOut & "," & RhOut & "#"
'Output string via the serial port
SerialOut(Com1,SerialOutString,"",0,100)
'Serial In Code
'Receives string "27.435,56.789" via COM2
'Uses * and # character as filters
SerialOpen(Com2,9600,0,0,10000)
'Open a serial port
255
Section 7. Installation
'Receive serial data as a string
'42 is ASCII code for "*", 35 is code for "#"
SerialInRecord(Com2,SerialInString,42,0,35,"",01)
'Parse the serial string
SplitStr(InStringSplit(),SerialInString,"",2,0)
NextScan
EndProg
7.9.17.6 Serial I/O Application Testing
A common problem when developing a serial I/O application is the lack of an
immediately available serial device with which to develop and test programs.
Using HyperTerminal, a developer can simulate the output of a serial device or
capture serial input.
Note HyperTerminal is provided as a utility with Windows XP and earlier
versions of Windows. HyperTerminal is not provided with later versions of
Windows, but can be purchased separately from http://www.hilgraeve.com.
HyperTerminal automatically converts binary data to ASCII on the screen.
Binary data can be captured, saved to a file, and then viewed with a hexadecimal
editor. Other terminal emulators are available from third-party vendors that
facilitate capture of binary or hexadecimal data.
7.9.17.6.1
Configure HyperTerminal
Create a HyperTerminal instance file by clicking Start | All Programs |
Accessories | Communications | HyperTerminal. The windows in the figures
HyperTerminal Connection Description (p. 256) through HyperTerminal ASCII
Setup (p. 258) are presented. Enter an instance name and click OK.
Figure 66. HyperTerminal New Connection Description
256
Section 7. Installation
Figure 67. HyperTerminal Connect-To Settings
Figure 68. HyperTerminal COM-Port Settings Tab
Click File | Properties | Settings | ASCII Setup... and set as shown.
257
Section 7. Installation
Figure 69. HyperTerminal ASCII Setup
7.9.17.6.2
Create Send-Text File
Create a file from which to send a serial string. The file shown in the figure
HyperTerminal Send Text-File Example (p. 258) will send the string
[2008:028:10:36:22]C to the CR1000. Use Notepad® (Microsoft® Windows®
utility) or some other text editor that will not place hidden characters in the file.
Figure 70. HyperTerminal Send Text-File Example
To send the file, click Transfer | Send Text File | Browse for file, then click OK.
7.9.17.6.3
Create Text-Capture File
Figure HyperTerminal Text-Capture File Example (p. 259) shows a HyperTerminal
capture file with some data. The file is empty before use commences.
258
Section 7. Installation
Figure 71. HyperTerminal Text-Capture File Example
Engage text capture by clicking on Transfer | Capture Text | Browse, select the
file, and then click OK.
7.9.17.6.4
Serial I/O Example II
CRBasic example Measure Sensors / Send RS-232 Data (p. 259) illustrates a use of
CR1000 serial I/O features.
Example — An energy company has a large network of older CR510 dataloggers
into which new CR1000 dataloggers are to be incorporated. The CR510
dataloggers are programmed to output data in the legacy Campbell Scientific
Printable ASCII format, which satisfies requirements of the customer's dataacquisition network. The network administrator prefers to synchronize the CR510
clocks from a central computer using the legacy Campbell Scientific C command.
The CR510 datalogger is hard-coded to output printable ASCII and recognize the
C command. CR1000 dataloggers, however, require custom programming to
output and accept these same ASCII strings. A similar program can be used to
emulate CR10X and CR23X dataloggers.
Solution — CRBasic example Measure Sensors / Send RS-232 Data (p. 259) imports
and exports serial data with the CR1000 RS-232 port. Imported data are expected
to have the form of the legacy Campbell Scientific time set C command. Exported
data has the form of the legacy Campbell Scientific Printable ASCII format.
Note The nine-pin RS-232 port can be used to download the CR1000 program if
the SerialOpen() baud rate matches that of the datalogger support software (p. 654).
However, two-way PakBus® communications will cause the CR1000 to
occasionally send unsolicited PakBus® packets out the RS-232 port for at least 40
seconds after the last PakBus® communication. This will produce some "noise" on
the intended data-output signal.
Monitor the CR1000 RS-232 port with HyperTerminal as described in the section
Configure HyperTerminal (p. 256). Send C-command file to set the clock according
to the text in the file.
Note The HyperTerminal file will not update automatically with actual time. The
file only simulates a clock source for the purposes of this example.
259
Section 7. Installation
CRBasic Example ϱ4.
Measure Sensors / Send RS-Ϯ3Ϯ Data
'This program example demonstrates the import and export serial data via the CR1000 RS-232
'port. Imported data are expected to have the form of the legacy Campbell Scientific
'time set C command:
'
[YR:DAY:HR:MM:SS]C
'Exported data has the form of the legacy Campbell Scientific Printable ASCII format:
'
01+0115. 02+135 03+00270 04+7999 05+00138 06+07999 07+04771
'Declarations
'Visible Variables
Public StationID
Public KWH_In
Public KVarH_I
Public KWHHold
Public KVarHold
Public KWHH
Public KvarH
Public InString As String * 25
Public OutString As String * 100
'Hidden Variables
Dim i, rTime(9), OneMinData(6), OutFrag(6) As String
Dim InStringSize, InStringSplit(5) As String
Dim Date, Month, Year, DOY, Hour, Minute, Second, uSecond
Dim LeapMOD4, LeapMOD100, LeapMOD400
Dim Leap4 As Boolean, Leap100 As Boolean, Leap400 As Boolean
Dim LeapYear As Boolean
Dim ClkSet(7) As Float
'One Minute Data Table
DataTable(OneMinTable,true,-1)
OpenInterval
'sets interval same as found in CR510
DataInterval(0,1,Min,10)
Totalize(1, KWHH,FP2,0)
Sample(1, KWHHold,FP2)
Totalize(1, KvarH,FP2,0)
Sample(1, KVarHold,FP2)
Sample(1, StationID,FP2)
EndTable
'Clock Set Record Data Table
DataTable(ClockSetRecord,True,-1)
Sample(7,ClkSet(),FP2)
EndTable
260
Section 7. Installation
'Subroutine to convert date formats (day-of-year to month and date)
Sub DOY2MODAY
'Store Year, DOY, Hour, Minute and Second to Input Locations.
Year = InStringSplit(1)
DOY = InStringSplit(2)
Hour = InStringSplit(3)
Minute = InStringSplit(4)
Second = InStringSplit(5)
uSecond = 0
'Check if it is a leap year:
'If Year Mod 4 = 0 and Year Mod 100 <> 0, then it is a leap year OR
'If Year Mod 4 = 0, Year Mod 100 = 0, and Year Mod 400 = 0, then it
'is a leap year
LeapYear = 0
'Reset leap year status location
LeapMOD4 = Year MOD 4
LeapMOD100 = Year MOD 100
LeapMOD400 = Year MOD 400
If LeapMOD4 = 0 Then Leap4 = True Else Leap4 = False
If LeapMOD100 = 0 Then Leap100 = True Else Leap100 = False
If LeapMOD400 = 0 Then Leap400 = True Else Leap400 = False
If Leap4 = True Then
LeapYear = True
If Leap100 = True Then
If Leap400 = True Then
LeapYear = True
Else
LeapYear = False
EndIf
EndIf
Else
LeapYear = False
EndIf
'If it is a leap year, use this section.
If (LeapYear = True) Then
Select Case DOY
Case Is < 32
Month = 1
Date = DOY
Case Is < 61
Month = 2
Date = DOY + -31
Case Is < 92
Month = 3
Date = DOY + -60
Case Is < 122
Month = 4
Date = DOY + -91
Case Is < 153
Month = 5
Date = DOY + -121
Case Is < 183
Month = 6
Date = DOY + -152
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Section 7. Installation
Case Is < 214
Month = 7
Date = DOY +
Case Is < 245
Month = 8
Date = DOY +
Case Is < 275
Month = 9
Date = DOY +
Case Is < 306
Month = 10
Date = DOY +
Case Is < 336
Month = 11
Date = DOY +
Case Is < 367
Month = 12
Date = DOY +
EndSelect
'If it is not a leap
Else
Select Case DOY
Case Is < 32
Month = 1
Date = DOY
Case Is < 60
Month = 2
Date = DOY +
Case Is < 91
Month = 3
Date = DOY +
Case Is < 121
Month = 4
Date = DOY +
Case Is < 152
Month = 5
Date = DOY +
Case Is < 182
Month = 6
Date = DOY +
Case Is < 213
Month = 7
Date = DOY +
Case Is < 244
Month = 8
Date = DOY +
Case Is < 274
Month = 9
Date = DOY +
262
-182
-213
-244
-274
-305
-335
year, use this section.
-31
-59
-90
-120
-151
-181
-212
-243
Section 7. Installation
Case Is < 305
Month = 10
Date = DOY + -273
Case Is < 336
Month = 11
Date = DOY + -304
Case Is < 366
Month = 12
Date = DOY + -334
EndSelect
EndIf
EndSub
'//////////////////////////// PROGRAM ////////////////////////////
BeginProg
StationID = 4771
Scan(1,Sec, 3, 0)
'/////////////////Measurement Section////////////////////////
'PulseCount(KWH_In, 1, 1, 2, 0, 1, 0) 'Activate this line in working program
KWH_In = 4.5
'Simulation -- delete this line from working program
'PulseCount(KVarH_I, 1, 2, 2, 0, 1, 0) 'Activate this line in working program
KVarH_I = 2.3
'Simulation -- delete this line from working program
KWHH = KWH_In
KvarH = KVarH_I
KWHHold = KWHH + KWHHold
KVarHold = KvarH + KVarHold
CallTable OneMinTable
'////////////////////Serial I/O Section/////////////////////
SerialOpen(ComRS232,9600,0,0,10000)
'///////////////Serial Time Set Input Section///////////////
'Accept old C command -- [2008:028:10:36:22]C -- parse, process, set
'clock (Note: Chr(91) = "[", Chr(67) = "C")
SerialInRecord(ComRS232,InString,91,0,67,InStringSize,01)
If InStringSize <> 0 Then
SplitStr(InStringSplit,InString,"",5,0)
Call DOY2MODAY
'Call subroutine to convert day-of-year
'to month & day
ClkSet(1) = Year
ClkSet(2) = Month
ClkSet(3) = Date
ClkSet(4) = Hour
ClkSet(5) = Minute
ClkSet(6) = Second
ClkSet(7) = uSecond
'Note: ClkSet array requires year, month, date, hour, min, sec, msec
ClockSet(ClkSet())
CallTable(ClockSetRecord)
EndIf
263
Section 7. Installation
'/////////////////Serial Output Section/////////////////////
'Construct old Campbell Scientific Printable ASCII data format and output to COM1
'Read datalogger clock
RealTime(rTime)
If TimeIntoInterval(0,5,Sec) Then
'Load OneMinData table data for processing into printable ASCII
GetRecord(OneMinData(),OneMinTable,1)
'Assign +/- Sign
For i=1 To 6
If OneMinData(i) < 0 Then
'Note: chr45 is - sign
OutFrag(i)=CHR(45) & FormatFloat(ABS(OneMinData(i)),"%05g")
Else
'Note: chr43 is + sign
OutFrag(i)=CHR(43) & FormatFloat(ABS(OneMinData(i)),"%05g")
EndIf
Next i
'Concatenate Printable ASCII string, then push string out RS-232
'(first 2 fields are ID, hhmm):
OutString = "01+0115." & " 02+" & FormatFloat(rTime(4),"%02.0f") & _
FormatFloat(rTime(5),"%02.0f")
OutString = OutString & " 03" & OutFrag(1) & " 04" & OutFrag(2) & _
" 05" & OutFrag(3)
OutString = OutString & " 06" & OutFrag(4) & " 07" & OutFrag(5) & _
CHR(13) & CHR(10) & "" 'add CR LF null
'Send printable ASCII string out RS-232 port
SerialOut(ComRS232,OutString,"",0,220)
EndIf
NextScan
EndProg
7.9.17.7 Serial I/O Q & A
Q: I am writing a CR1000 program to transmit a serial command that contains a
null character. The string to transmit is:
CHR(02)+CHR(01)+"CWGT0"+CHR(03)+CHR(00)+CHR(13)+CHR(10)
How does the logger handle the null character?
Is there a way that we can get the logger to send this?
A: Strings created with CRBasic are NULL terminated. Adding strings together
means the second string will start at the first null it finds in the first string.
Use SerialOutBlock() instruction, which lets you send null characters, as shown
below.
SerialOutBlock(COMRS232, CHR(02) + CHR(01) + "CWGT0" +
CHR(03),8)
SerialOutBlock(COMRS232, CHR(0),1)
SerialOutBlock(COMRS232, CHR(13) + CHR(10),2)
Q: Please summarize when the CR1000 powers the RS-232 port. I get that there
is an "always on" setting. How about when there are beacons? Does the
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Section 7. Installation
SerialOpen() instruction cause other power cycles?
A: The RS-232 port is left on under the following conditions:
x
x
When the setting RS-232Power (p. 627) is set
When a SerialOpen() with argument COMRS232 is used in the program
Both conditions power-up the interface and leave it on with no timeout. If
SerialClose() is used after SerialOpen(), the port is powered down and in a state
waiting for characters to come in.
Under normal operation, the port is powered down waiting for input. After
receiving input, there is a 40 second software timeout that must expire before
shutting down. The 40 second timeout is generally circumvented when
communicating with the datalogger support software (p. 95) because the software
sends information as part of the protocol that lets the CR1000 know that it can
shut down the port.
When in the "dormant" state with the interface powered down, hardware is
configured to detect activity and wake up, but there is the penalty of losing the
first character of the incoming data stream. PakBus® takes this into consideration
in the "ring packets" that are preceded with extra sync bytes at the start of the
packet. For this reason SerialOpen() leaves the interface powered up so no
incoming bytes are lost.
When the CR1000 has data to send with the RS-232 port, if the data are not a
response to a received packet, such as sending a beacon, it will power up the
interface, send the data, and return to the "dormant" state with no 40 second
timeout.
Q: How can I reference specific characters in a string?
A: The third 'dimension' of a string variable provides access to that part of the
string after the position specified. For example, if
TempData = "STOP"
then,
TempData(1,1,2) = "TOP"
TempData(1,1,3) = "OP"
TempData(1,1,1) = "STOP"
To handle single-character manipulations, declare a string with a size of 1. This
single-character string is then used to search for specific characters. In the
following example, the first character of string LargerString is determined and
used to control program logic:
Public TempData As String * 1
TempData = LargerString
If TempData = "S" Then...
A single character can be retrieved from any position in a string. The following
example retrieves the fifth character of a string:
Public TempData As String * 1
TempData = LargerString(1,1,5)
Q: How can I get SerialIn(), SerialInBlock(), and SerialInRecord() to read
extended characters?
265
Section 7. Installation
A: Open the port in binary mode (mode 3) instead of PakBus-enabled mode
(mode 0).
Q: Tests with an oscilloscope showed the sensor was responding quickly, but the
data were getting held up in the internals of the CR1000 somewhere for 30 ms or
so. Characters at the start of a response from a sensor, which come out in 5 ms,
were apparently not accessible by the program for 30 ms or so; in fact, no data
were in the serial buffer for 30 ms or so.
A: As a result of internal buffering in the CR1000 and / or external interfaces, data
may not appear in the serial port buffer for a period ranging up to 50 ms
(depending on the serial port being used). This should be kept in mind when
setting timeouts for the SerialIn() and SerialOut() instructions, or user-defined
timeouts in constructs using the SerialInChk() instruction.
Q: What are the termination conditions that will stop incoming data from being
stored?
A: Termination conditions:
x
x
x
TerminationChar argument is received
MaxNumChars argument is met
TimeOut argument is exceeded
SerialIn() does NOT stop storing when a Null character (&h00) is received
(unless a NULL character is specified as the termination character). As a string
variable, a NULL character received will terminate the string, but nevertheless
characters after a NULL character will continue to be received into the variable
space until one of the termination conditions is met. These characters can later be
accessed with MoveBytes() if necessary.
Q: How can a variable populated by SerialIn() be used in more than one
sequence and still avoid using the variable in other sequences when it contains old
data?
A: A simple caution is that the destination variable should not be used in more
than one sequence to avoid using the variable when it contains old data.
However, this is not always possible and the root problem can be handled more
elegantly.
When data arrives independent from execution of the CRBasic program, such as
occurs with streaming data, measures must be taken to ensure that the incoming
data are updated in time for subsequent processes using that data. When the task
of writing data is separate from the task of reading data, you should control the
flow of data with deliberate control features such as the use of flags or a timestamped weigh point as can be obtained from a data table.
There is nothing unique about SerialIn() with regard to understanding how to
correctly write to and read from global variables using multiple sequences.
SerialIn() is writing into an array of characters. Many other instructions write
into an array of values (characters, floats, or longs), such as Move(),
MoveBytes(), GetVariables(), SerialInRecord(), SerialInBlock(). In all cases,
when writing to an array of values, it is important to understand what you are
reading, if you are reading it asynchronously, in other words reading it from some
other task that is polling for the data at the same time as it is being written,
whether that other task is some other machine reading the data, like LoggerNet, or
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Section 7. Installation
a different sequence, or task, within the same machine. If the process is relatively
fast, like the Move() instruction, and an asynchronous process is reading the data,
this can be even worse because the “reading old data” will happen less often but is
more insidious because it is so rare.
7.9.18 Serial I/O: SDI-12 Sensor Support — Programming
Resource
Related Topics:
‡SDI-12 Sensor Support — Overview (p. 72)
‡SDI-12 Sensor Support — Details (p. 363)
‡Serial I/O: SDI-12 Sensor Support — Programming Resource (p. 267)
‡SDI-12 Sensor Support — Instructions (p. 555)
See the table CR1000 Terminal Definitions (p. 76) for C terminal assignments for
SDI-12 input. Multiple SDI-12 sensors can be connected to each configured
terminal. If multiple sensors are wired to a single terminal, each sensor must have
a unique address. SDI-12 standard v 1.3 sensors accept addresses 0 through 9, a
through z, and A through Z. For a CRBasic programming example demonstrating
the changing of an SDI-12 address on the fly, see Campbell Scientific publication
PS200/CH200 12 V Charging Regulators, which is available at
www.campbellsci.com.
The CR1000 supports SDI-12 communication through two modes — transparent
mode and programmed mode.
x
x
Transparent mode facilitates sensor setup and troubleshooting. It allows
commands to be manually issued and the full sensor response viewed.
Transparent mode does not record data.
Programmed mode automates much of the SDI-12 protocol and provides for
data recording.
7.9.18.1 SDI-12 Transparent Mode
System operators can manually interrogate and enter settings in probes using
transparent mode. Transparent mode is useful in troubleshooting SDI-12 systems
because it allows direct communication with probes.
Transparent mode may need to wait for commands issued by the programmed
mode to finish before sending responses. While in transparent mode, CR1000
programs may not execute. CR1000 security may need to be unlocked before
transparent mode can be activated.
Transparent mode is entered while the PC is in telecommunications with the
CR1000 through a terminal emulator program. It is easily accessed through a
terminal emulator. Campbell Scientific DevConfig program has a terminal utility,
as to other datalogger support software (p. 95). Keyboard displays cannot be used.
To enter the SDI-12 transparent mode, enter the datalogger support software
terminal emulator as shown in the figure Entering SDI-12 Transparent Mode (p.
268). Press Enter until the CR1000 responds with the prompt CR1000>. Type
SDI12 at the prompt and press Enter. In response, the query Enter Cx Port is
presented with a list of available ports. Enter the port number assigned to the
terminal to which the SDI-12 sensor is connected. For example, port 1 is entered
for terminal C1. An Entering SDI12 Terminal response indicates that SDI-12
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Section 7. Installation
transparent mode is active and ready to transmit SDI-12 commands and display
responses.
Figure 72. Entering SDI-12 Transparent Mode
7.9.18.1.1
SDI-12 Transparent Mode Commands
Commands have three components:
x
x
x
Sensor address (a) — a single character, and is the first character of the
command. Sensors are usually assigned a default address of zero by the
manufacturer. Wildcard address (?) is used in the Address Query command.
Some manufacturers may allow it to be used in other commands.
Command body (for example, M1) — an upper case letter (the “command”)
followed by alphanumeric qualifiers.
Command termination (!) — an exclamation mark.
An active sensor responds to each command. Responses have several standard
forms and terminate with <CR><LF> (carriage return–line feed).
SDI-12 commands and responses are defined by the SDI-12 Support Group
(www.sdi-12.org) and are summarized in the table Standard SDI-12 Command &
Response Set (p. 269). Sensor manufacturers determine which commands to
support. The most common commands are detailed in the table SDI-12
Commands for Transparent Mode (p. 269).
268
Section 7. Installation
Table 43. SDI-12 Commands for Transparent Mode
Command Name
Command Syntax
Continuous
spacing for at least
12 milliseconds
Break
Address Query
?!
Acknowledge Active
a!
Response
1
2
Notes
None
a<CR><LF>
a<CR><LF>
Change Address
aAb!
b<CR><LF> (support for this command is required only if the sensor
supports software changeable addresses)
Start Concurrent Measurement
aC!
atttnn<CR><LF>
aC1! ... aC9!
atttnn<CR><LF>
aCC1! ... aCC9!
atttnn<CR><LF>
Additional Concurrent
Measurements
Additional Concurrent
Measurements and Request CRC
Send Data
aD0! ... aD9!
aI!
allccccccccmmmmmmvvvxxx...xx<CR><LF>. For example,
013CampbellCS1234003STD.03.01 means address = 0, SDI-12 protocol
version number = 1.3, manufacturer is Campbell Scientific, CS1234 is the
sensor model number (fictitious in this example), 003 is the sensor version
number, STD.03.01 indicates the sensor revision number is .01.
aM!
atttn<CR><LF>
aMC!
atttn<CR><LF>
aM1! ... aM9!
atttn<CR><LF>
aMC1! ... aMC9!
atttn<CR><LF>
Send Identification
Start Measurement
3
3
Start Measurement and Request CRC
3
Additional Measurements
Additional Measurements and
Request CRC
3
Continuous Measurements
aR0! ... aR9!
Continuous Measurements and
Request CRC
Start Verification
a<values><CR><LF> or a<values><CRC><CR><LF>
aRC0! ... aRC9!
3
aV!
a<values><CR><LF> (formatted like the D commands)
a<values><CRC><CR><LF> (formatted like the D commands)
atttn<CR><LF>
1
If the terminator '!' is not present, the command will not be issued. The CRBasic SDI12Recorder() instruction, however, will still pick up data
resulting from a previously issued C! command.
2
3
Complete response string can be obtained when using the SDI12Recorder() instruction by declaring the Destination variable as String.
This command may result in a service request.
SDI-12 Address Commands
Address and identification commands request metadata about the sensor. Connect
only a single probe when using these commands.
?!
Requests the sensor address. Response is address, a.
Syntax:
?!
269
Section 7. Installation
aAb!
Changes the sensor address. a is the current address and b is the new address.
Response is the new address.
Syntax:
aAb!
aI!
Requests the sensor identification. Response is defined by the sensor
manufacturer, but usually includes the sensor address, SDI-12 version,
manufacturer's name, and sensor model information. Serial number or other
sensor specific information may also be included.
Syntax:
aI!
An example of a response from the aI! command is:
013NRSYSINC1000001.2101 <CR><LF>
where:
0 is the SDI-12 address.
13 is the SDI-12 version (1.3).
NRSYSINC indicates the manufacturer.
100000 indicates the sensor model.
1.2 is the sensor version.
101 is the sensor serial number.
SDI-12 Start Measurement Commands
Measurement commands elicite responses in the form:
atttnn
where:
a is the sensor address
ttt is the time (s) until measurement data are available
nn is the number of values to be returned when one or more subsequent D!
commands are issued.
aMv!
Starts a standard measurement. Qualifier v is a variable between 1 and 9. If
supported by the sensor manufacturer, v requests variant data. Variants may
include alternate units (e.g., °C or °F), additional values (e.g., level and
temperature), or a diagnostic of the sensor internal battery.
Syntax:
aMv!
As an example, the response from the command 5M! is:
500410
270
Section 7. Installation
where:
5 reports the sensor SDI-12 address.
004 indicates the data will be available in 4 seconds.
10 indicates that 10 values will be available.
The command 5M7! elicites a similar response, but the appendage 7 instructs the
sensor to return the voltage of the internal battery.
aC!
Start concurrent measurement. The CR1000 requests a measurement, continues
program execution, and picks up the requested data on the next pass through the
program. A measurement request is then sent again so data are ready on the next
scan. The datalogger scan rate should be set such that the resulting skew between
time of measurement and time of data collection does not compromise data
integrity. This command is new with v. 1.2 of the SDI-12 specification.
Syntax:
aC!
Aborting an SDI-12 Measurement Command
A measurement command (M! or C!) is aborted when any other valid command is
sent to the sensor.
SDI-12 Send Data Command
Send data commands are normally issued automatically by the CR1000 after the
aMv! or aCv! measurement commands. In transparent mode through CR1000
terminal commands, you need to issue these commands in series. When in
automatic mode, if the expected number of data values are not returned in
response to a aD0! command, the datalogger issues aD1!, aD2!, etc., until all data
are received. In transparent mode, you must do likewise. The limiting constraint
is that the total number of characters that can be returned to a aDv! command is
35 (75 for aCv!). If the number of characters exceed the limit, the remainder of
the response are obtained with subsequent aDv! commands wherein v increments
with each iteration.
aDv!
Request data from the sensor.
Example Syntax:
aD0!
SDI-12 Continuous Measurement Command (aR0! to aR9!)
Sensors that are continuously monitoring, such as a shaft encoder, do not require
an M command. They can be read directly with the Continuous Measurement
Command (R0! to R9!). For example, if the sensor is operating in a continuous
measurement mode, then aR0! will return the current reading of the sensor.
Responses to R commands are formatted like responses to send data (aDv!)
commands. The main difference is that R commands do not require a preceding
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Section 7. Installation
M command. The maximum number of characters returned in the <values> part
of the response is 75.
Each R command is an independent measurement. For example, aR5! need not
be preceded by aR0! through aR4!. If a sensor is unable to take a continuous
measurement, then it must return its address followed by <CR><LF> (carriage
return and line feed) in response to an R command. If a CRC was requested, then
the <CR><LF> must be preceded by the CRC.
aRv!
Request continuous data from the sensor.
Example Syntax:
aR5!
7.9.18.2 SDI-12 Recorder Mode
The CR1000 can be programmed to act as an SDI-12 recording device or as an
SDI-12 sensor.
For troubleshooting purposes, responses to SDI-12 commands can be captured in
programmed mode by placing a variable declared As String in the variable
parameter. Variables not declared As String will capture only numeric data.
Another troubleshooting tool is the terminal-mode snoop utility, which allows
monitoring of SDI-12 traffic. Enter terminal mode as described in SDI-12
Transparent Mode (p. 267), issue CRLF (<Enter> key) until CR1000> prompt
appears. Type W and then <Enter>. Type 9 in answer to Select:, 100 in answer
to Enter timeout (secs):, Y to ASCII (Y)?. SDI-12 communications are then
opened for viewing.
The SDI12Recorder() instruction automates the issuance of commands and
interpretation of sensor responses. Commands entered into the SDIRecorder()
instruction differ slightly in function from similar commands entered in
transparent mode. In transparent mode, for example, the operator manually enters
aM! and aD0! to initiate a measurement and get data, with the operator providing
the proper time delay between the request for measurement and the request for
data. In programmed mode, the CR1000 provides command and timing services
within a single line of code. For example, when the SDI12Recorder() instruction
is programmed with the M! command (note that the SDI-12 address is a separate
instruction parameter), the CR1000 issues the aM! and aD0! commands with
proper elapsed time between the two. The CR1000 automatically issues retries
and performs other services that make the SDI-12 measurement work as trouble
free as possible. Table SDI-12Recorder() Commands (p. 272) summarizes CR1000
actions triggered by some SDI12Recorder() commands.
If the SDI12Recorder() instruction is not successful, NAN will be loaded into the
first variable. See NAN and ±INF (p. 482) for more information.
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Section 7. Installation
SDI-12 Command Sent
Command Name
1
Sensor Response
CR1000 Response
SDIRecorder()
SDICommand
Argument
Notes
CR1000: issues a?! command. Only one sensor can be attached to the C
terminal configured for SDI-12 for this command to elicit a response.
Sensor must support this command.
Address Query
?!
Change Address
Ab!
CR1000: issues aAb! command
Cv!, CCv!
CR1000: issues aCv! command
Concurrent Measurement
Sensor: responds with atttnn
CR1000: if ttt = 0, issues aDv! command(s). If nnn = 0 then NAN put in
the first element of the array.
Sensor: responds with data
CR1000: else, if ttt > 0 then moves to next CRBasic program instruction
CR1000: at next time SDIRecorder() is executed, if elapsed time < ttt,
moves to next CRBasic instruction
CR1000: else, issues aDv! command(s)
Sensor: responds with data
CR1000: issues aCv! command (to request data for next scan)
Alternate Concurrent Measurement
Cv
2
(note — no ! termination)
CR1000: tests to see if ttt expired. If ttt not expired, loads 1e9 into first variable and
then moves to next CRBasic instruction. If ttt expired, issues aDv! command(s).
See section Alternate Start Concurrent Measurement Command (Cv) (p. 273)
Sensor: responds to aDv! command(s) with data, if any. If no data, loads
NAN into variable.
CR1000: moves to next CRBasic instruction (does not re-issue aCv!
command)
Send Identification
I!
Start Measurement
M!, Mv!, MCv!
CR1000: issues aI! command
CR1000: issues aMv! command
Sensor: responds with atttnn
CR1000: If nnn = 0 then NAN put in the first element of the array.
3
CR1000: waits until ttt seconds (unless a service request is received).
Issues aDv! command(s). If a service request is received, issues aDv!
immediately.
Sensor: responds with data
Continuous Measurements
Start Verification
1
Rv!, RCv!
CR1000: issues aRv! command
V!
CR1000: issues aV! command
See table SDI-12 Commands for Transparent Mode (p. 269) for complete sensor responses.
2
Use variable replacement in program to use same instance of SDI12Recorder() as issued aCV! (see the CRBasic example Using Alternate
Concurrent Command (aC) (p. 277) ).
3
Note that ttt is local only to the SDIRecorder() instruction. If a second SDIRecorder() instruction is used, it will have its own ttt.
Note aCv and aCv! are different commands — aCv does not end with !.
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Section 7. Installation
The SDIRecorder() aCv command facilitates using the SDI-12 standard Start
Concurrent command (aCv!) without the back-to-back measurement sequence
normal to the CR1000 implementation of aCv!.
Consider an application wherein four SDI-12 temperature sensors need to be nearsimultaneously measured at a five minute interval within a program that scans
every five seconds. The sensors requires 95 seconds to respond with data after a
measurement request. Complicating the application is the need for minimum
power usage, so the sensors must power down after each measurement.
This application provides a focal point for considering several measurement
strategies. The simplest measurement is to issue a M! measurement command to
each sensor as shown in the following CRBasic example:
Public BatteryVolt
Public Temp1, Temp2, Temp3, Temp4
BeginProg
Scan(5,Sec,0,0)
'Non-SDI-12 measurements here
SDI12Recorder(Temp1,1,0,"M!",1.0,0)
SDI12Recorder(Temp2,1,1,"M!",1.0,0)
SDI12Recorder(Temp3,1,2,"M!",1.0,0)
SDI12Recorder(Temp4,1,3,"M!",1.0,0)
NextScan
EndProg
However, the code sequence has three problems:
1. It does not allow measurement of non-SDI-12 sensors at the required frequency
because the SDI12Recorder() instruction takes too much time.
2. It does not achieve required five-minute sample rate because each
SDI12Recorder() instruction will take about 95 seconds to complete before
the next SDI12Recorder() instruction begins, resulting is a real scan rate of
about 6.5 minutes.
3. There is a 95 s time skew between each sensor measurement.
Problem 1 can be remedied by putting the SDI-12 measurements in a
SlowSequence scan. Doing so allows the SDI-12 routine to run its course
without affecting measurement of other sensors, as follows:
Public BatteryVolt
Public Temp(4)
BeginProg
Scan(5,Sec,0,0)
'Non-SDI-12 measurements here
NextScan
SlowSequence
Scan(5,Min,0,0)
SDI12Recorder(Temp(1),1,0,"M!",1.0,0)
SDI12Recorder(Temp(2),1,1,"M!",1.0,0)
SDI12Recorder(Temp(3),1,2,"M!",1.0,0)
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Section 7. Installation
SDI12Recorder(Temp(4),1,3,"M!",1.0,0)
NextScan
EndSequence
EndProg
However, problems 2 and 3 still are not resolved. These can be resolved by using
the concurrent measurement command, C!. All measurements will be made at
about the same time and execution time will be about 95 seconds, well within the
5 minute scan rate requirement, as follows:
Public BatteryVolt
Public Temp(4)
BeginProg
Scan(5,Sec,0,0)
'Non-SDI-12 measurements here
NextScan
SlowSequence
Scan(5,Min,0,0)
SDI12Recorder(Temp(1),1,0,"C!",1.0,0)
SDI12Recorder(Temp(2),1,1,"C!",1.0,0)
SDI12Recorder(Temp(3),1,2,"C!",1.0,0)
SDI12Recorder(Temp(4),1,3,"C!",1.0,0)
NextScan
EndProg
A new problem introduced by the C! command, however, is that it causes high
power usage by the CR1000. This application has a very tight power budget.
Since the C! command reissues a measurement request immediately after
receiving data, the sensors will be in a high power state continuously. To remedy
this problem, measurements need to be started with C! command, but stopped
short of receiving the next measurement command (hard-coded part of the C!
routine) after their data are polled. The SDI12Recorder() instruction C command
(not C!) provides this functionality as shown in CRBasic example Using Alternate
Concurrent Command (aC) (p. 277). A modification of this program can also be
used to allow near-simultaneous measurement of SDI-12 sensors without
requesting additional measurements, such as may be needed in an event-driven
measurement.
Note When only one SDI-12 sensor is attached, that is, multiple sensor
measurements do not need to start concurrently, another reliable method for
making SDI-12 measurements without affecting the main scan is to use the
CRBasic SlowSequence instruction and the SDI-12 M! command. The main
scan will continue to run during the ttt time returned by the SDI-12 sensor. The
trick is to synchronize the returned SDI-12 values with the main scan.
aCv
Start alternate concurrent measurement.
Syntax:
aCv
275
Section 7. Installation
CRBasic Example ϱϱ.
Using SDI1ϮSensor() to Test Cv Command
'This program example demonstrates how to use CRBasic to simulate four SDI-12 sensors. This
program can be used to
'produce measurements to test the CRBasic example Using Alternate Concurrent Command (aC) (p. 277).
Public Temp(4)
DataTable(Temp,True,0)
DataInterval(0,5,Min,10)
Sample(4,Temp(),FP2)
EndTable
BeginProg
Scan(5,Sec,0,0)
PanelTemp(Temp(1),250) 'Measure CR1000 wiring panel temperature to use as base for
'simulated temperatures Temp(2), Temp(3), and Temp(4).
Temp(2) = Temp(1) + 5
Temp(3) = Temp(1) + 10
Temp(4) = Temp(1) + 15
CallTable Temp
NextScan
SlowSequence
Do
'Note SDI12SensorSetup / SDI12SensorResponse must be renewed
'after each successful SDI12Recorder() poll.
SDI12SensorSetup(1,1,0,95)
Delay(1,95,Sec)
SDI12SensorResponse(Temp(1))
Loop
EndSequence
SlowSequence
Do
SDI12SensorSetup(1,3,1,95)
Delay(1,95,Sec)
SDI12SensorResponse(Temp(2))
Loop
EndSequence
SlowSequence
Do
SDI12SensorSetup(1,5,2,95)
Delay(1,95,Sec)
SDI12SensorResponse(Temp(3))
Loop
EndSequence
276
Section 7. Installation
SlowSequence
Do
SDI12SensorSetup(1,7,3,95)
Delay(1,95,Sec)
SDI12SensorResponse(Temp(4))
Loop
EndSequence
EndProg
CRBasic Example ϱ6.
Using Alternate Concurrent Command (aC)
'This program example demonstrates the use of the special SDI-12 concurrent measurement
'command (aC) when back-to-back measurements are not desired, as can occur in an application
'that has a tight power budget. To make full use of the aC command, measurement control
'logic is used.
'Declare variables
Dim X
Public RunSDI12
Public Cmd(4)
Public Temp_Tmp(4)
Public Retry(4)
Public IndDone(4)
Public Temp_Meas(4)
Public GroupDone
'Main Program
BeginProg
'Preset first measurement command to C!
For X = 1 To 4
cmd(X) = "C!"
Next X
'Set five-second scan rate
Scan(5,Sec,0,0)
'Other measurements here
'Set five-minute SDI-12 measurement rate
If TimeIntoInterval(0,5,Min) Then RunSDI12 = True
'Begin measurement sequence
If RunSDI12 = True Then
For X = 1 To 4
Temp_Tmp(X) = 2e9
Next X
'when 2e9 changes, indicates a change
277
Section 7. Installation
'Measure SDI-12 sensors
SDI12Recorder(Temp_Tmp(1),1,0,cmd(1),1.0,0)
SDI12Recorder(Temp_Tmp(2),1,1,cmd(2),1.0,0)
SDI12Recorder(Temp_Tmp(3),1,2,cmd(3),1.0,0)
SDI12Recorder(Temp_Tmp(4),1,3,cmd(4),1.0,0)
'Control Measurement Event
For X = 1 To 4
If cmd(X) = "C!" Then Retry(X) = Retry(X) + 1
If Retry(X) > 2 Then IndDone(X) = -1
'Test to see if ttt expired. If ttt not expired, load "1e9" into first variable
'then move to next instruction. If ttt expired, issue aDv! command(s).
If ((Temp_Tmp(X) = 2e9) OR (Temp_Tmp(X) = 1e9)) Then
cmd(X) = "C"
'Start sending "C" command.
ElseIf(Temp_Tmp(X) = NAN) Then
cmd(X) = "C!"
'Comms failed or sensor not attached
'Start measurement over
Else 'C!/C command sequence complete
Move(Temp_Meas(X),1,Temp_Tmp(X),1) 'Copy measurements to SDI_Val(10)
cmd(X) = "C!"
'Start next measurement with "C!"
IndDone(X) = -1
EndIf
Next X
'Summarize Measurement Event Success
For X = 1 To 4
GroupDone = GroupDone + IndDone(X)
Next X
'Stop current measurement event, reset controls
If GroupDone = -4 Then
RunSDI12 = False
GroupDone = 0
For X = 1 To 4
IndDone(X) = 0
Retry(X) = 0
Next X
Else
GroupDone = 0
EndIf
EndIf
'End of measurement sequence
NextScan
EndProg
SDI12Recorder() sends any string enclosed in quotation marks in the Command
parameter. If the command string is a non-standard SDI-12 command, any
response is captured into the variable assigned to the Destination parameter, so
long as that variable is declared As String. CRBasic example Use of an SDI-12
Extended Command (p. 279) shows appropriate code for sending an extended SDI12 command and receiving the response. The extended command feature has no
built-in provision for responding with follow-up commands. However, the
program can be coded to parse the response and issue subsequent SDI-12
commands based on a customized evaluation of the response. For more
278
Section 7. Installation
information on parsing strings, see Input Programming Basics (p. 251).
CRBasic Example ϱ7.
Using an SDI-1Ϯ Extended Command
'This program example demonstrates the use of SDI-12 extended commands. In this example,
'a temperature measurement, tt.tt, is sent to a CH200 Charging Regulator using the command
'XTtt.tt!'. The response from the CH200 should be '0OK', if 0 is the SDI-12 address.
'
'Declare Variables
Public PTemp As Float
Public SDI12command As String
Public SDI12result As String
'Main Program
BeginProg
Scan(20,Sec,3,0)
PanelTemp(PTemp,250)
SDI12command = "XT" & FormatFloat(PTemp,"%4.2f") & "!"
SDI12Recorder(SDI12result,1,0,SDI12command,1.0,0)
NextScan
EndProg
7.9.18.3 SDI-12 Sensor Mode
The CR1000 can be programmed to act as an SDI-12 recording device or as an
SDI-12 sensor.
For troubleshooting purposes, responses to SDI-12 commands can be captured in
programmed mode by placing a variable declared As String in the variable
parameter. Variables not declared As String will capture only numeric data.
Another troubleshooting tool is the terminal-mode snoop utility, which allows
monitoring of SDI-12 traffic. Enter terminal mode as described in SDI-12
Transparent Mode (p. 267), issue CRLF (<Enter> key) until CR1000> prompt
appears. Type W and then <Enter>. Type 9 in answer to Select:, 100 in answer
to Enter timeout (secs):, Y to ASCII (Y)?. SDI-12 communications are then
opened for viewing.
The SDI12SensorSetup() / SDI12SensorResponse() instruction pair programs
the CR1000 to behave as an SDI-12 sensor. A common use of this feature is the
transfer of data from the CR1000 to other Campbell Scientific dataloggers over a
single-wire interface (terminal configured for SDI-12 to terminal configured for
SDI-12), or to transfer data to a third-party SDI-12 recorder.
Details of using the SDI12SensorSetup() / SDI12SensorResponse() instruction
pair can be found in the CRBasic Editor Help. Other helpful tips include:
Concerning the Reps parameter in the SDI12SensorSetup(), valid Reps when
expecting an aMx! command range from 0 to 9. Valid Reps when expecting an
aCx! command are 0 to 20. The Reps parameter is not range-checked for valid
entries at compile time. When the SDI-12 recorder receives the sensor response
of atttn to a aMx! command, or atttnn to a aCx! command, only the first digit n,
or the first two digits nn, are used. For example, if Reps is mis-programmed as
123, the SDI-12 recorder will accept only a response of n = 1 when issuing an
aMx! command, or a response of nn = 12 when issuing an aCx! command.
279
Section 7. Installation
When programmed as an SDI-12 sensor, the CR1000 will respond to SDI-12
commands M, MC, C, CC, R, RC, V, ?, and I. See table SDI-12 Commands for
Transparent Mode (p. 269) for full command syntax. The following rules apply:
1. A CR1000 can be assigned only one SDI-12 address per SDI-12 port. For
example, a CR1000 will not respond to both 0M! AND 1M! on SDI-12 port
C1. However, different SDI-12 ports can have unique SDI-12 addresses. Use
a separate SlowSequence for each SDI-12 port configured as a sensor.
2. The CR1000 will handle additional measurement (aMx!) commands. When an
SDI-12 recorder issues aMx! commands as shown in CRBasic example SDI12 Sensor Setup (p. 280), measurement results are returned as listed in table SDI12 Sensor Setup — Results (p. 280).
CRBasic Example ϱ8.
SDI-1Ϯ Sensor Setup
'This program example demonstrates the use of the SDI12SensorSetup()/SDI12SensorResponse()
'instruction pair to program the CR1000 to emulate an SDI-12 sensor. A common use of this
'feature is the transfer of data from the CR1000 to SDI-12 compatible instruments, including
'other Campbell Scientific dataloggers, over a single-wire interface (SDI-12 port to
'SDI-12 port). The recording datalogger simply requests the data using the aD0! command.
Public PanelTemp
Public Batt_volt
Public SDI_Source(10)
BeginProg
Scan(5,Sec,0,0)
PanelTemp(PanelTemp,250)
Battery(batt_volt)
SDI_Source(1)
SDI_Source(2)
SDI_Source(3)
SDI_Source(4)
SDI_Source(5)
SDI_Source(6)
SDI_Source(7)
SDI_Source(8)
SDI_Source(9)
SDI_Source(10)
=
=
=
=
=
=
=
=
=
=
PanelTemp
batt_volt
PanelTemp * 1.8 + 32
batt_volt
PanelTemp
batt_volt * 1000
PanelTemp * 1.8 + 32
batt_volt * 1000
Status.SerialNumber
Status.LithiumBattery
NextScan
SlowSequence
Do
SDI12SensorSetup(10,1,0,1)
Delay(1,500,mSec)
SDI12SensorResponse(SDI_Source)
Loop
EndSequence
EndProg
280
'temperature, degrees C
'primary power, volts dc
'temperature, degrees F
'primary power, volts dc
'temperature, degrees C
'primary power, millivolts dc
'temperature in degrees F
'primary power, millivolts dc
'serial number
'data backup battery, V
Section 7. Installation
Table 44. SDI-12 Sensor Setup CRBasic Example — Results
Measurement
Command from
SDI-12 Recorder
Source Variables
Accessed from the
CR1000 acting as a
SDI-12 Sensor
Contents of
Source Variables
0M!
Source(1), Source(2)
temperature °C, battery voltage
0M0!
Same as 0M!
0M1!
Source(3), Source(4)
temperature °F, battery voltage
0M2!
Source(5), Source(6)
temperature °C, battery mV
0M3!
Source(7), Source(8)
temperature °F, battery mV
0M4!
Source(9), Source(10)
serial number, lithium battery
voltage
7.9.18.4 SDI-12 Power Considerations
When a command is sent by the CR1000 to an SDI-12 probe, all probes on the
same SDI-12 port will wake up. However, only the probe addressed by the
datalogger will respond. All other probes will remain active until the timeout
period expires.
Example:
Probe: Water Content
Power Usage:
x
x
x
x
x
Quiescent: 0.25 mA
Measurement: 120 mA
Measurement time: 15 s
Active: 66 mA
Timeout: 15 s
Probes 1, 2, 3, and 4 are connected to SDI-12 / control port C1.
The time line in table Example Power Usage Profile for a Network of SDI-12
Probes (p. 281) shows a 35 second power-usage profile example.
For most applications, total power usage of 318 mA for 15 seconds is not
excessive, but if 16 probes were wired to the same SDI-12 port, the resulting
power draw would be excessive. Spreading sensors over several SDI-12 terminals
will help reduce power consumption.
281
Section 7. Installation
Table 45. Example Power Usage Profile for a Network of SDI-12 Probes
Time (s)
Command
All
Probes
Awake
1
1M!
Yes
Time
Out
Expires
1 mA
2 mA
3 mA
4 mA
Total
mA
120
66
66
66
318
2
120
66
66
66
318
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
14
120
66
66
66
318
120
66
66
66
318
66
66
66
66
264
17
66
66
66
66
264
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
29
66
66
66
66
264
66
66
66
66
264
31
0.25
0.25
0.25
0.25
1
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
‡
35
0.25
0.25
0.25
0.25
1
15
16
Yes
1D0!
Yes
30
Yes
7.9.19 String Operations
String operations are performed using CRBasic string functions, as listed in String
Functions (p. 574).
7.9.19.1 String Operators
The table String Operators (p. 282) lists and describes available string operators.
String operators are case sensitive.
282
Section 7. Installation
Table 46. String Operators
Operator
&
Description
Concatenates strings. Forces numeric values to strings before
concatenation.
Example
1 & 2 & 3 & "a" & 5 & 6 & 7 = "123a567"
+
Adds numeric values until a string is encountered. When a string is
encountered, it is appended to the sum of the numeric values. Subsequent
numeric values are appended as strings.
Example:
1 + 2 + 3 + "a" + 5 + 6 + 7 = "6a567"
"Subtracts" NULL ("") from the end of ASCII characters for conversion to
an ASCII code (LONG data type).
Example:
"a" - "" = 97
ASCII codes of the first characters in each string are compared. If the
difference between the codes is zero, codes for the next characters are
compared. When unequal codes or NULL are encountered (NULL
terminates all strings), the difference between the last compared ASCII
codes is returned.
-
Examples:
Note — ASCII code for a = 97, b = 98, c = 99, d = 100, e = 101, and all
strings end with NULL.
Difference between NULL and NULL
"abc" - "abc" = 0
Difference between e and c
"abe" - "abc" = 2
Difference between c and b
"ace" - "abe" = 1
Difference between d and NULL
"abcd" - "abc" = 100
ASCII codes of the first characters in each string are compared. If the
difference between the codes is zero, codes for the next characters are
compared. When unequal codes or NULL are encountered (NULL
terminates all strings), the requested comparison is made. If the comparison
is true, -1 or True is returned. If false, 0 or False is returned.
<, >, <>, <=, >=, =
Examples:
Expression
x = "abc" = "abc"
x = "abe" = "abc"
x = "ace" > "abe"
Result
x = -1 or True
x = 0 or False
x = -1 or True
7.9.19.2 String Concatenation
Concatenation is the building of strings from other strings ("abc123"), characters
("a" or chr()), numbers, or variables. The table String Concatenation Examples (p.
284) lists some expressions and expected results. CRBasic example Concatenation
of Numbers and Strings (p. 284) demonstrates several concatenation examples.
When non-string values are concatenated with strings, once a string is
encountered, all subsequent operands will first be converted to a string before the
283
Section 7. Installation
+ operation is performed. When working with strings, exclusive use of the &
operator ensures that no string value will be converted to an integer.
Table 47. String Concatenation Examples
Expression
Comments
Result
Str(1) = 5.4 + 3 + " Volts"
Add floats, concatenate strings
"8.4 Volts"
Str(2) = 5.4 & 3 & " Volts"
Concatenate floats and strings
"5.43 Volts"
Lng(1) = "123"
Convert string to long
123
Lng(2) = 1+2+"3"
Add floats to string / convert to long
33
Lng(3) = "1"+2+3
Concatenate string and floats
123
Lng(4) = 1&2&"3"
Concatenate floats and string
123
CRBasic Example ϱ9.
Concatenation of Numbers and Strings
'This program example demonstrates the concatenation of numbers and strings to variables
'declared As Float and As String.
'
'Declare Variables
Public Num(12) As Float
Public Str(2) As String
Dim I
BeginProg
Scan(1,Sec,0,0)
I = 0 'Set I to zero
'Data type of the following destination variables is Float
'because Num() array is declared As Float.
I += 1 'Increment I by 1 to clock through sequential elements of the Num() array
'As shown in the following expression, if all parameter are numbers, the result
'of using '+' is a sum of the numbers:
Num(I) = 2 + 3 + 4
'= 9
'Following are examples of using '+' and '*' when one or more parameters are strings.
'Parameters are processed in the standard order of operations. In the order of
'operation, once a string or an '&' is processed, all following parameters will
'be processed (concatenated) as strings:
I += 1
Num(I) = "1" + 2 + 3 + 4
'= 1234
I += 1
Num(I) = 1 + "2" + 3 + 4
'= 1234
I += 1
Num(I) = 1 + 2 + "3" + 4
'= 334
I += 1
Num(I) = 1 + 2 + 3 + "4"
'= 64
284
Section 7. Installation
I += 1
Num(I)
I += 1
Num(I)
I += 1
Num(I)
I += 1
Num(I)
I += 1
Num(I)
= 1 + 2 + "3" + 4 + 5 + "6"
'= 33456
= 1 + 2 + "3" + (4 + 5) + "6"
'= 3396
= 1 + 2 + "3" + 4 * 5 + "6"
'= 33206
= 1 & 2 + 3 + 4
'= 1234
= 1 + 2 + 3 & 4
'= 64
'If a non-numeric string is attempted to be processed into a float destination,
'operations are truncated at that point
I += 1
Num(I) = 1 + 2 + "hey" + 4 + 5 + "6"
'= 3
I += 1
Num(I) = 1 + 2 + "hey" + (4 + 5) + "6"
'= 3
'The same rules apply when the destination is of data type String, except in the
'case wherein a non-numeric string is encountered as follows. Data type of the
'following destination variables is String because Str() array is declared As String.
I = 0
I += 1
Str(I) = 1 + 2 + "hey" + 4 + 5 + "6"
I += 1
Str(I) = 1 + 2 + "hey" + (4 + 5) + "6"
'= 3hey456
'= 3hey96
NextScan
EndProg
7.9.19.3 String NULL Character
All strings are automatically NULL terminated. NULL is the same as Chr(0) or
"", counts as one of the characters in the string. Assignment of just one character
is that character followed by a NULL, unless the character is a NULL.
Table 48. String NULL Character Examples
Expression
Comments
Result
LongVar(5) = "#"-""
Subtract NULL, ASCII code results
35
LongVar(6) = StrComp("#","")
Also subtracts NULL
35
Example:
Objective:
Insert a NULL character into a string, and then reconstitute the string.
Given:
StringVar(3) = "123456789"
Execute:
StringVar(3,1,4) = ""
"123<NULL>56789"
StringVar(4) = StringVar(3)
"123"
Results:
285
Section 7. Installation
but,
StringVar(3) still = "123<NULL>56789",
so,
StringVar(5) = StringVar(3,1,4+1)
'"56789"
StringVar(6) = StringVar(3) + 4 + StringVar(3,1,4+1)
'"123456789"
Some smart sensors send strings containing NULL characters. To manipulate a
string that has NULL characters within it (in addition to being terminated with
another NULL), use MoveBytes() instruction.
7.9.19.4 Inserting String Characters
Example:
Objective:
Use MoveBytes() to change "123456789" to "123A56789"
Given:
StringVar(7) = "123456789"
"123456789"
'Result is
try (does not work):
StringVar(7,1,4) = "A"
"123A<NULL>56789"
'Result is
Instead, use:
StringVar(7) = MoveBytes(Strings(7,1,4),0,"A",0,1)
"123A56789"
'Result is
7.9.19.5 Extracting String Characters
A specific character in the string can be accessed by using the "dimensional"
syntax; that is, when the third dimension of a string is specified, the third
dimension is the character position.
Table 49. Extracting String Characters
Expression
286
Comments
Result
StringVar(3) = "Go Jazz"
Loads string into variable
StringVar(3) = "Go Jazz"
StringVar(4) = StringVar(3,1,4)
Extracts single character
StringVar(4) = "J"
Section 7. Installation
7.9.19.6 String Use of ASCII / ANSII Codes
Table 50. Use of ASCII / ANSII Codes Examples
Expression
Comments
Result
LongVar (7) = ASCII("#")
35
LongVar (8) = ASCII("*")
42
LongVar (9) = "#"
Cannot be converted to Long with
NULL
NAN
LongVar (1) = "#"-""
Can be converted to Long without
NULL
35
7.9.19.7 Formatting Strings
Table 51. Formatting Strings Examples
Expression
Str(1)=123e4
Str(2)=FormatFloat(123e4,"%12.2f")
Str(3)=FormatFloat(Values(2)," The battery is %.3g Volts ")
Str(4)=Strings(3,1,InStr(1,Strings(3),"The battery is ",4))
Str(5)=Strings(3,1,InStr(1,Strings(3),"is ",2) + 3)
Str(6)=Replace("The battery is 12.4 Volts"," is "," = ")
Str(7)=LTrim("The battery is 12.4 Volts")
Str(8)=RTrim("The battery is 12.4 Volts")
Str(9)=Trim("The battery is 12.4 Volts")
Str(10)=UpperCase("The battery is 12.4 Volts")
Str(12)=Left("The battery is 12.4 Volts",5)
Str(13)=Right("The battery is 12.4 Volts",7)
CRBasic Example 60.
Result
1230000
1230000.00
“The battery is 12.4 Volts”
12.4 Volts
12.4 Volts
The battery = 12.4 Volts
The battery is 12.4 Volts
The battery is 12.4 Volts
The battery is 12.4 Volts
THE BATTERY IS 12.4 VOLTS
The b
Volts
Formatting Strings
'This program example demonstrates the formatting of string variables. To run the
'demonstration, send this program to the CR1000. String formatting will occur
'automatically.
'Objective:
'Extract "12.4 Volts" from the string "The battery is 12.4 Volts"
Public StringVar As String
BeginProg
'Note line continuation character _
StringVar() = Mid("The battery is 12.4 Volts", _
InStr(1,"The battery is 12.4 Volts"," is ",2)+3,Len("The battery is 12.4 Volts"))
EndProg
287
Section 7. Installation
7.9.19.8 Formatting String Hexadecimal Variables
Table 52. Formatting Hexadecimal Variables — Examples
Expression
Comment
Result
CRLFNumeric(1) = &H0d0a
Add leading zero to hex step 1
3338
StringVar(20) = "0" & Hex(CRLFNumeric)
Add leading zero to hex step 2
0D0A
CRLFNumeric(2) = HexToDec(Strings(20))
Convert Hex string to Float
3338.00
7.9.20 Subroutines
A subroutine is a group of programming instructions that is called by, but runs
outside of, the main program. Subroutines are used for the following reasons:
x
x
x
To reduce program length. Subroutine code can be executed multiple times
in a program scan.
To ease integration of proven code segments into new programs.
To compartmentalize programs to improve organization.
By executing the Call() instruction, the main program can call a subroutine from
anywhere in the program.
A subroutine has access to all global variables (p. 517). Variables local (p. 519) to a
subroutine are declared within the subroutine instruction. Local variables can be
aliased (as of 4/2013; OS 26) but are not displayed in the Public table. Global
and local variables can share the same name and not conflict. If global variables
are passed to local variables of different type, the same type conversion rules
apply as apply to conversions among variables declared as Public or Dim. See
Expressions with Numeric Data Types (p. 162) for conversion types.
Note To avoid programming conflicts, pass information into local variables and /
or define some global variables and use them exclusively by a subroutine.
CRBasic example Subroutine with Global and Local Variables (p. 288) shows the
use of global and local variables. Variables counter() and pi_product are global.
Variable i_sub is global but used exclusively by subroutine process. Variables j()
and OutVar are local since they are declared as parameters in the Sub()
instruction,
Sub process(j(4) AS Long,OutVar).
Variable j() is a four-element array and variable OutVar is a single-element
array. The call statement,
Call ProcessSub (counter(1),pi_product)
passes five values into the subroutine: pi_product and four elements of array
counter(). Array counter() is used to pass values into, and extract values from,
the subroutine. The variable pi_product is used to extract a value from the
subroutine.
Call() passes the values of all listed variables into the subroutine. Values are
passed back to the main scan at the end of the subroutine.
288
Section 7. Installation
CRBasic Example 61.
Subroutine with Global and Local Variables
'This program example demonstrates the use of global and local variables with subroutines.
'
'Global variables are those declared anywhere in the program as Public or Dim.
'Local variables are those declared in the Sub() instruction.
'Program Function: Passes two variables to a subroutine. The subroutine increments each
'variable once per second, multiplies each by pi, then passes results back to the main
'program for storage in a data table.
'Global variables (Used only outside subroutine by choice)
'Declare Counter in the Main Scan.
Public counter(2) As Long
'Declare Product of PI * counter(2).
Public pi_product(2) As Float
'Global variable (Used only in subroutine by choice)
'For / Next incrementor used in the subroutine.
Public i_sub As Long
'Declare Data Table
DataTable(pi_results,True,-1)
Sample(1,counter(),IEEE4)
EndTable
'Declare Subroutine
'Declares j(4) as local array (can only be used in subroutine)
Sub ProcessSub (j(2) As Long,OutVar(2) As Float)
For i_sub = 1 To 2
j(i_sub) = j(i_sub) + 1
'Processing to show functionality
OutVar(i_sub) = j(i_sub) * 4 * ATN(1)
'(Tip: 4 * ATN(1) = pi to IEEE4 precision)
Next i_sub
EndSub
BeginProg
counter(1) = 1
counter(2) = 2
Scan(1,Sec,0,0)
'Pass Counter() array to j() array, pi_pruduct() to OutVar()
Call ProcessSub (counter(),pi_product())
CallTable pi_results
NextScan
EndProg
7.9.21 TCP/IP — Details
Related Topics:
‡TCP/IP — Overview (p. 91)
‡TCP/IP — Details (p. 423)
‡TCP/IP — Instructions (p. 593)
‡TCP/IP Links — List (p. 652)
289
Section 7. Installation
The following TCP/IP protocols are supported by the CR1000 when using
network-links (p. 652) that use the resident IP stack or when using a cell modem with
the PPP/IP key enabled. More information on some of these protocols is in the
following sections.
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
DHCP
DNS
FTP
HTML
HTTP
Micro-serial server
NTCIP
NTP
PakBus over TCP/IP
Ping
POP3
SMTP
SNMP
Telnet
Web API (p. 423)
XML
The most up-to-date information on implementing these protocols is contained in
CRBasic Editor Help. For a list of CRBasic instructions, see the appendix
TCP/IP (p. 593).
Read More Specific information concerning the use of digital-cellular modems
for TCP/IP can be found in Campbell Scientific manuals for those modems. For
information on available TCP/IP/PPP devices, refer to the appendix Network
Links (p. 652) for model numbers. Detailed information on use of TCP/IP/PPP
devices is found in their respective manuals (available at www.campbellsci.com
http://www.campbellsci.com) and CRBasic Editor Help.
7.9.21.1 PakBus Over TCP/IP and Callback
Once the hardware has been configured, basic PakBus® communication over
TCP/IP is possible. These functions include the following:
x
x
x
x
x
Sending programs
Retrieving programs
Setting the CR1000 clock
Collecting data
Displaying the current record in a data table
Data callback and datalogger-to-datalogger communications are also possible over
TCP/IP. For details and example programs for callback and datalogger-todatalogger communications, see the network-link manual. A listing of networklink model numbers is found in the appendix Network Links (p. 652).
290
Section 7. Installation
7.9.21.2 Default HTTP Web Server
The CR1000 has a default home page built into the operating system. The home
page can be accessed using the following URL:
http:\\ipaddress:80
Note Port 80 is implied if the port is not otherwise specified.
As shown in the figure, Preconfigured HTML Home Page (p. 291), this page
provides links to the newest record in all tables, including the Status table, Public
table, and data tables. Links are also provided for the last 24 records in each data
table. If fewer than 24 records have been stored in a data table, the link will
display all data in that table.
Newest-Record links refresh automatically every 10 seconds. Last 24-Records
link must be manually refreshed to see new data. Links will also be created
automatically for any HTML, XML, and JPEG files found on the CR1000 drives.
To copy files to these drives, choose File Control from the datalogger support
software (p. 512) menu.
Figure 73. Preconfigured HTML Home Page
7.9.21.3 Custom HTTP Web Server
Although the default home page cannot be accessed for editing, it can be replaced
with the HTML code of a customized web page. To replace the default home
page, save the new home page under the name default.html and copy it to the
datalogger. It can be copied to a CR1000 drive with File Control. Deleting
default.html will cause the CR1000 to use the original, default home page.
The CR1000 can be programmed to generate HTML or XML code that can be
viewed by a web browser. CRBasic example HTML (p. 293) shows how to use the
CRBasic instructions WebPageBegin() / WebPageEnd and HTTPOut() to
create HTML code. Note that for HTML code requiring the use of quotation
marks, CHR(34) is used, while regular quotation marks are used to define the
291
Section 7. Installation
beginning and end of alphanumeric strings inside the parentheses of the
HTTPOut() instruction. For additional information, see the CRBasic Editor Help.
In this example program, the default home page is replaced by using
WebPageBegin to create a file called default.html. The new default home page
created by the program appears as shown in the figure Home Page Created using
WebPageBegin() Instruction (p. 292).
The Campbell Scientific logo in the web page comes from a file called
SHIELDWEB2.JPG that must be transferred from the PC to the CR1000 CPU:
drive using File Control in the datalogger support software.
A second web page, shown in figure Customized Numeric-Monitor Web Page (p.
"monitor.html" was created by the example program that contains links
to the CR1000 data tables.
293) called
Figure 74. Home Page Created Using WebPageBegin() Instruction
292
Section 7. Installation
Figure 75. Customized Numeric-Monitor Web Page
CRBasic Example 6Ϯ.
Custom Web Page HTML
'This program example demonstrates the creation of a custom web page that resides in the
'CR1000. In this example program, the default home page is replaced by using WebPageBegin to
'create a file called default.html. The graphic in the web page (in this case, the Campbell
'Scientific logo) comes from a file called SHIELDWEB2.JPG. The graphic file must be copied to
'the CR1000 CPU: drive using File Control in the datalogger support software. A second web
'page is created that contains links to the CR1000 data tables.
'NOTE: The "_" character used at the end of some lines allows a code statement to be wrapped
'to the next line.
Dim Commands As String * 200
Public Time(9), RefTemp,
Public Minutes As String, Seconds As String, Temperature As String
DataTable(CRTemp,True,-1)
DataInterval(0,1,Min,10)
Sample(1,RefTemp,FP2)
Average(1,RefTemp,FP2,False)
EndTable
'Default HTML Page
WebPageBegin("default.html",Commands)
HTTPOut("<html>")
HTTPOut("<style>body {background-color: oldlace}</style>")
HTTPOut("<body><title>Campbell Scientific CR1000 Datalogger</title>")
HTTPOut("<h2>Welcome To the Campbell Scientific CR1000 Web Site!</h2>")
HTTPOut("<tr><td style=" + CHR(34) +"width: 290px" + CHR(34) + ">")
HTTPOut("<a href=" + CHR(34) + "http://www.campbellsci.com" + CHR(34) + ">")
HTTPOut("<img src="+ CHR(34) +"/CPU/SHIELDWEB2.jpg"+ CHR(34) + "width=" + _
CHR(34) +"128"+CHR(34)+"height="+CHR(34)+"155"+ CHR(34) + "class=" + _
CHR(34) +"style1"+ CHR(34) +"/></a></td>")
HTTPOut("<p><h2> Current Data:</h2></p>")
HTTPOut("<p>Time: " + time(4) + ":" + minutes + ":" + seconds + "</p>")
293
Section 7. Installation
HTTPOut("<p>Temperature: " + Temperature + "</p>")
HTTPOut("<p><h2> Links:</h2></p>")
HTTPOut("<p><a href="+ CHR(34) +"monitor.html"+ CHR(34)+">Monitor</a></p>")
HTTPOut("</body>")
HTTPOut("</html>")
WebPageEnd
'Monitor Web Page
WebPageBegin("monitor.html",Commands)
HTTPOut("<html>")
HTTPOut("<style>body {background-color: oldlace}</style>")
HTTPOut("<body>")
HTTPOut("<title>Monitor CR1000 Datalogger Tables</title>")
HTTPOut("<p><h2>CR1000 Data Table Links</h2></p>")
HTTPOut("<p><a href="+ CHR(34) + "command=TableDisplay&table=CRTemp&records=10" + _
CHR(34)+">Display Last 10 Records from DataTable CR1Temp</a></p>")
HTTPOut("<p><a href="+ CHR(34) + "command=NewestRecord&table=CRTemp"+ CHR(34) + _
">Current Record from CRTemp Table</a></p>")
HTTPOut("<p><a href="+ CHR(34) + "command=NewestRecord&table=Public"+ CHR(34) + _
">Current Record from Public Table</a></p>")
HTTPOut("<p><a href="+ CHR(34) + "command=NewestRecord&table=Status" + CHR(34) + _
">Current Record from Status Table</a></p>")
HTTPOut("<br><p><a href="+ CHR(34) +"default.html"+ CHR(34) + ">Back to the Home Page _
</a></p>")
HTTPOut("</body>")
HTTPOut("</html>")
WebPageEnd
BeginProg
Scan(1,Sec,3,0)
PanelTemp(RefTemp,250)
RealTime(Time())
Minutes = FormatFloat(Time(5),"%02.0f")
Seconds = FormatFloat(Time(6),"%02.0f")
Temperature = FormatFloat(RefTemp, "%02.02f")
CallTable(CRTemp)
NextScan
EndProg
7.9.21.4 FTP Server
The CR1000 automatically runs an FTP server. This allows Windows® Explorer®
to access the CR1000 file system with FTP, with drives on the CR1000 being
mapped into directories or folders. The root directory on the CR1000 can be any
drive, but the USR: drive is usually preferred. USR: is a drive created by
allocating memory in the USR: Drive Size box on the Deployment | Advanced
tab of the CR1000 service in DevConfig. Files can be copied / pasted between
drives. Files can be deleted through FTP.
7.9.21.5 FTP Client
The CR1000 can act as an FTP client to send a file or get a file from an FTP
server, such as another datalogger or web camera. This is done using the
CRBasic FTPClient() instruction. Refer to a manual for a Campbell Scientific
network link (see the appendix Network Links (p. 652) ), available at
www.campbellsci.com, or CRBasic Editor Help for details and sample programs.
294
Section 7. Installation
7.9.21.6 Telnet
Telnet is used to access the same commands that are available through the support
software terminal emulator (p. 530). Start a Telnet session by opening a DOS
command prompt and type in:
Telnet xxx.xxx.xxx.xxx <Enter>
where xxx.xxx.xxx.xxx is the IP address of the network device connected to the
CR1000.
7.9.21.7 SNMP
Simple Network Management Protocol (SNMP) is a part of the IP suite used by
NTCIP and RWIS for monitoring road conditions. The CR1000 supports SNMP
when a network device is attached.
7.9.21.8 Ping (IP)
Ping can be used to verify that the IP address for the network device connected to
the CR1000 is reachable. To use the Ping tool, open a command prompt on a
computer connected to the network and type in:
ping xxx.xxx.xxx.xxx <Enter>
where xxx.xxx.xxx.xxx is the IP address of the network device connected to the
CR1000.
7.9.21.9 Micro-Serial Server
The CR1000 can be configured to allow serial communication over a TCP/IP port.
This is useful when communicating with a serial sensor over Ethernet with microserial server (third-party serial to Ethernet interface) to which the serial sensor is
connected. See the network-link manual and the CRBasic Editor Help for the
TCPOpen() instruction for more information. Information on available network
links is available in the appendix Network Links (p. 652).
7.9.21.10
Modbus TCP/IP
The CR1000 can perform Modbus communication over TCP/IP using the Modbus
TCP/IP interface. To set up Modbus TCP/IP, specify port 502 as the ComPort in
the ModBusMaster() and ModBusSlave() instructions. See the CRBasic Editor
Help for more information. See Modbus (p. 411).
7.9.21.11
DHCP
When connected to a server with a list of IP addresses available for assignment,
the CR1000 will automatically request and obtain an IP address through the
Dynamic Host Configuration Protocol (DHCP). Once the address is assigned, use
DevConfig, PakBusGraph, Connect, or the CR1000KD Keyboard Display to look
in the CR1000 Status table to see the assigned IP address. This is shown under
the field name IPInfo.
295
Section 7. Installation
7.9.21.12
DNS
The CR1000 provides a Domain Name Server (DNS) client that can query a DNS
server to determine if an IP address has been mapped to a hostname. If it has, then
the hostname can be used interchangeably with the IP address in some datalogger
instructions.
7.9.21.13
SMTP
Simple Mail Transfer Protocol (SMTP) is the standard for e-mail transmissions.
The CR1000 can be programmed to send e-mail messages on a regular schedule
or based on the occurrence of an event.
7.9.22 Wind Vector
The WindVector() instruction processes wind-speed and direction measurements
to calculate mean speed, mean vector magnitude, and mean vector direction over a
data-storage interval. Measurements from polar (wind speed and direction) or
orthogonal (fixed East and North propellers) sensors are supported. Vector
direction and standard deviation of vector direction can be calculated weighted or
unweighted for wind speed.
7.9.22.1 OutputOpt Parameters
In the CR1000 WindVector() instruction, the OutputOpt parameter defines the
processed data that are stored. All output options result in an array of values, the
elements of which have _WVc(n) as a suffix, where n is the element number. The
array uses the name of the Speed/East variable as its base. Table OutputOpt
Options (p. 296) lists and describes OutputOpt options.
Table 53. WindVector() OutputOpt Options
Option
Description (WVc() is the Output Array)
WVc(1): Mean horizontal wind speed (S)
WVc(2): Unit vector mean wind direction (Ĭ
0
1
WVc(3): Standard deviation of wind direction VĬ6WDQGDUGGHYLDWLRQLV
calculated using the Yamartino algorithm. This option complies with EPA
guidelines for use with straight-line Gaussian dispersion models to model plume
transport.
WVc(1): Mean horizontal wind speed (S)
:9F8QLWYHFWRUPHDQZLQGGLUHFWLRQĬ
WVc(1): Mean horizontal wind speed (S)
WVc(2): Resultant mean horizontal wind speed (U)
:9F5HVXOWDQWPHDQZLQGGLUHFWLRQĬX
296
2
:9F6WDQGDUGGHYLDWLRQRIZLQGGLUHFWLRQıĬX. This standard deviation is
calculated using Campbell Scientific's wind speed weighted algorithm. Use of the
resultant mean horizontal wind direction is not recommended for straight-line
Gaussian dispersion models, but may be used to model transport direction in a
variable-trajectory model.
3
:9F8QLWYHFWRUPHDQZLQGGLUHFWLRQĬ
Section 7. Installation
Table 53. WindVector() OutputOpt Options
Option
Description (WVc() is the Output Array)
:9F8QLWYHFWRUPHDQZLQGGLUHFWLRQĬ
4
:9F6WDQGDUGGHYLDWLRQRIZLQGGLUHFWLRQıĬX7KLVVWDQGDUGGHYLDWLRQLV
calculated using Campbell Scientific's wind speed weighted algorithm. Use of the
resultant mean horizontal wind direction is not recommended for straight-line
Gaussian dispersion models, but may be used to model transport direction in a
variable-trajectory model.
7.9.22.2 Wind Vector Processing
WindVector() uses a zero-wind-speed measurement when processing scalar wind
speed only. Because vectors require magnitude and direction, measurements at
zero wind speed are not used in vector speed or direction calculations. This
means, for example, that manually-computed hourly vector directions from 15
minute vector directions will not agree with CR1000-computed hourly vector
directions. Correct manual calculation of hourly vector direction from 15 minute
vector directions requires proper weighting of the 15 minute vector directions by
the number of valid (non-zero wind speed) wind direction samples.
Note Cup anemometers typically have a mechanical offset which is added to each
measurement. A numeric offset is usually encoded in the CRBasic program to
compensate for the mechanical offset. When this is done, a measurement will
equal the offset only when wind speed is zero; consequently, additional code is
often included to zero the measurement when it equals the offset so that
WindVector() can reject measurements when wind speed is zero.
Standard deviation can be processed one of two ways: 1) using every sample
taken during the data storage interval (enter 0 for the Subinterval parameter), or
2) by averaging standard deviations processed from shorter sub-intervals of the
data-storage interval. Averaging sub-interval standard deviations minimizes the
effects of meander under light wind conditions, and it provides more complete
information for periods of transition (see EPA publication "On-site
Meteorological Program Guidance for Regulatory Modeling Applications").
Standard deviation of horizontal wind fluctuations from sub-intervals is calculated
as follows:
where:
is the standard deviation over the data-storage interval, and
are sub-interval standard deviations. A sub-interval is
specified as a number of scans. The number of scans for a sub-interval is given
by:
Desired sub-interval (secs) / scan rate (secs)
For example, if the scan rate is 1 second and the data-output interval is 60
minutes, the standard deviation is calculated from all 3600 scans when the subinterval is 0. With a sub-interval of 900 scans (15 minutes) the standard deviation
is the average of the four sub-interval standard deviations. The last sub-interval is
weighted if it does not contain the specified number of scans.
297
Section 7. Installation
The EPA recommends hourly standard deviation of horizontal wind direction
(sigma theta) be computed from four fifteen-minute sub-intervals.
7.9.22.2.1
Measured Raw Data
x
x
x
x
x
7.9.22.2.2
Si: horizontal wind speed
Ĭi: horizontal wind direction
Uei: east-west component of wind
Uni: north-south component of wind
N: number of samples
Calculations
Input Sample Vectors
Figure 76. Input Sample Vectors
In figure Input Sample Vectors (p. 298), the short, head-to-tail vectors are the input
sample vectors described by si DQGĬi, the sample speed and direction, or by Uei
and Uni, the east and north components of the sample vector. At the end of datastorage interval T, the sum of the sample vectors is described by a vector of
PDJQLWXGH8DQGGLUHFWLRQĬX,IWKHLQSXWVDPSOHLQWHUYDOLVWWKHQXPEHURI
samples in data-storage interval T is N = T / t. The mean vector magnitude is Nj U / N.
Scalar mean horizontal wind speed, S:
where in the case of orthogonal sensors:
Unit vector mean wind direction,
298
Section 7. Installation
where
or, in the case of orthogonal sensors
where
Standard deviation of wind direction (Yamartino algorithm)
where,
and Ux and Uy are as defined above.
Mean Wind Vector
5HVXOWDQWPHDQKRUL]RQWDOZLQGVSHHGNj
Figure 77. Mean Wind-Vector Graph
where for polar sensors:
299
Section 7. Installation
or, in the case of orthogonal sensors:
Resultant mean wind direFWLRQĬX
6WDQGDUGGHYLDWLRQRIZLQGGLUHFWLRQıĬXXVLQJ&DPSEHOO6FLHQWLILF
algorithm:
7KHDOJRULWKPIRUıĬXLVGHveloped by noting, as shown in the figure Standard
Deviation of Direction (p. 300), that
where
Standard Deviation of Direction
Figure 78. Standard Deviation of Direction
The Taylor Series for the Cosine function, truncated after 2 terms is:
For deviations less than 40 degrees, the error in this approximation is less than
1%. At deviations of 60 degrees, the error is 10%.
The speed sample can be expressed as the deviation about the mean speed,
(TXDWLQJWKHWZRH[SUHVVLRQVIRU&RVș
DQGXVLQJWKHSUHYLRXVHTXDWLRQIRUVi;
6ROYLQJIRUĬi')2, one obtains;
300
Section 7. Installation
Summing (Ĭi')2 RYHU1VDPSOHVDQGGLYLGLQJE\1\LHOGVWKHYDULDQFHRIĬX
Note The sum of the last term equals 0.
The term,
is 0 if the deviations in speed are not correlated with the deviation in direction.
This assumption has been verified in tests on wind data by Campbell Scientific;
the Air Resources Laboratory, NOAA, Idaho Falls, ID; and MERDI, Butte, MT.
In these tests, the maximum differences in
and
have never been greater than a few degrees.
The final form is arrived at by converting from radians to degrees (57.296
degrees/radian).
301
8.
Operation
Reading List
‡Quickstart (p. 41)
‡Specifications (p. 97)
‡Installation (p. 99)
‡Operation (p. 303)
8.1
Measurements — Details
Related Topics:
‡Sensors — Quickstart (p. 42)
‡Measurements — Overview (p. 62)
‡Measurements — Details (p. 303)
‡Sensors — Lists (p. 649)
Several features give the CR1000 the flexibility to measure most sensor types.
Contact a Campbell Scientific application engineer if assistance is required in
assessing CR1000 compatibility to a specific application or sensor type. Some
sensors require precision excitation or a source of power. See the section
Switched Voltage Output — Details (p. 103).
8.1.1
Time Keeping — Details
Related Topics:
‡Time Keeping — Overview (p. 75)
‡Time Keeping — Details (p. 303)
Measurement of time is an essential function of the CR1000. Time measurement
with the on-board clock enables the CR1000 to attach time stamps to data,
measure the interval between events, and time the initiation of control functions.
8.1.1.1 Time Stamps
A measurement without an accurate time reference has little meaning. Data on
the CR1000 are stored with time stamps. How closely a time stamp corresponds
to the actual time a measurement is taken depends on several factors.
The time stamp in common CRBasic programs matches the time at the beginning
of the current scan as measured by the real-time clock in the CR1000. If a scan
starts at 15:00:00, data output during that scan will have a time stamp of 15:00:00
regardless of the length of the scan or when in the scan a measurement is made.
The possibility exists that a scan will run for some time before a measurement is
made. For instance, a scan may start at 15:00:00, execute time-consuming code,
then make a measurement at 15:00:00.51. The time stamp attached to the
measurement, if the CallTable() instruction is called from within the Scan() /
NextScan construct, will be 15:00:00, resulting in a time-stamp skew of 510 ms.
Time-stamp skew is not a problem with most applications because,
x
program execution times are usually short, so time stamp skew is only a few
milliseconds. Most measurement requirements allow for a few milliseconds
of skew.
303
Section 8. Operation
x
data processed into averages, maxima, minima, and so forth are composites
of several measurements. Associated time stamps only reflect the time the
last measurement was made and processing calculations were completed, so
the significance of the exact time a specific sample was measured diminishes.
Applications measuring and storing sample data wherein exact time stamps are
required can be adversely affected by time-stamp skew. Skew can be avoided by
x
x
CRBasic Example 63.
Making measurements in the scan before time-consuming code.
Programming the CR1000 such that the time stamp reflects the system time
rather than the scan time. When CallTable() is executed from within the
Scan() / NextScan construct, as is normally done, the time stamp reflects
scan time. By executing the CallTable() instruction outside the Scan() /
NextScan construct, the time stamp will reflect system time instead of scan
time. CRBasic example Time Stamping with System Time (p. 304) shows the
basic code requirements. The DataTime() instruction is a more recent
introduction that facilitates time stamping with system time. See Data Table
Declarations (p. 540) and CRBasic Editor Help for more information.
Time Stamping with System Time
'This program example demonstrates the time stamping of data with system time instead of
'the default use of scan time (time at which a scan started).
'
'Declare Variables
Public value
'Declare data table
DataTable(Test,True,1000)
Sample(1,Value,FP2)
EndTable
SequentialMode
BeginProg
Scan(1,Sec,10,0)
'Delay -- in an operational program, delay may be caused by other code
Delay(1,500,mSec)
'Measure Value -- can be any analog measurement
PanelTemp(Value,0)
'Immediately call SlowSequence to execute CallTable()
TriggerSequence(1,0)
NextScan
'Allow data to be stored 510 ms into the Scan with a s.51 time stamp
SlowSequence
Do
WaitTriggerSequence
CallTable(Test)
Loop
EndProg
304
Section 8. Operation
Other time-processing CRBasic instructions are governed by these same rules.
Consult CRBasic Editor Help for more information on specific instructions.
8.1.2
Analog Measurements — Details
Related Topics:
‡Analog Measurements — Overview (p. 63)
‡Analog Measurements — Details (p. 305)
The CR1000 measures the following sensor analog output types:
x
Voltage
o
o
x
x
x
x
Single-ended
Differential
Current (using a resistive shunt)
Resistance
Full-bridge
Half-bridge
Sensor connection is to H/L] terminals configurable for differential (DIFF) or
single-ended (SE) inputs. For example, differential channel 1 is comprised of
terminals 1H and 1L, with 1H as high and 1L as low.
8.1.2.1 Voltage Measurements — Details
Related Topicss:
‡9ROWDJH0HDVXUHPHQWV— Specifications
‡Voltage Measurements — Overview (p. 63)
‡Voltage Measurements — Details (p. 305)
8.1.2.1.1 Voltage Measurement Mechanics
Measurement Sequence
An analog-voltage measurement, as illustrated in the figure Simplified Voltage
Measurement Sequence (p. 306), proceeds as follows:
1. Switch
2. Settle
3. Amplify
4. Integrate
5. A to D (successive approximation)
6. Measurement scaled with multiplier and offset
7. Scaled value placed in memory
305
Section 8. Operation
FIGURE. Simplified Voltage Measurement Sequence -- 8 10 30
Figure 79. Simplified voltage measurement sequence
Voltage measurements are made using a successive approximation A-to-D (p. 507)
converter to achieve a resolution of 14 bits. Prior to the A-to-D, a high
impedance programmable-gain instrumentation amplifier (PGIA) amplifies the
signal. See figure Programmable Gain Input Amplifier (PGIA) (p. 306). The
CRBasic program controls amplifier gain and configuration — either single-ended
input or differential input. Internal multiplexers route individual terminals to the
PGIA.
Timing of measurement tasks is precisely controlled. The measurement schedule
is determined at compile time and loaded into memory.
Using two different voltage-measurement instructions with the same voltage
range takes about twice as long as using one instruction with two repetitions.
Parameters listed in table CRBasic Parameters Varying Measurement Sequence
and Timing (p. 307) vary sequence and timing of voltage measurement instructions.
Figure 80. Programmable Gain Input Amplifier (PGIA)
A voltage measurement proceeds as follows:
1. Set PGIA gain for the voltage range selected with the CRBasic measurement
instruction parameter Range.
2. Turn on excitation to the level selected with ExmV.
3. Multiplex selected terminals (InChan) to the PGIA and delay for the entered
settling time (SettlingTime).
4. Integrate the signal (see section Measurement Integration (p. 307) ) and perform
the A-to-D conversion.
5. Repeat for excitation reversal and input reversal as determined by parameters
RevEx and RevDiff.
6. Apply multitplier (Mult) and offset (Offset) to measured result.
306
Section 8. Operation
The CR1000 measures analog voltage by integrating the input signal for a fixed
duration and then holding the integrated value during the successive
approximation analog-to-digital (A-to-D) conversion. The CR1000 can make and
store measurements from up to eight differential or 16 single-ended channels
configured from H/L terminals at the minimum scan interval of 10 ms (100 Hz)
using fast-measurement-programming techniques as discussed in Measurements:
Faster Analog Rates (p. 229). The maximum conversion rate is 2000 per second (2
kHz) for measurements made on a one single-ended channel.
Table 54. CRBasic Parameters Varying Measurement Sequence and
Timing
CRBasic Parameter
Description
MeasOfs
Correct ground offset on single-ended measurements.
SettlingTime
Sensor input settling time.
Integ
Duration of input signal integration.
RevDiff
Reverse high and low differential inputs.
RevEx
Reverse polarity of excitation voltage.
Measurement Integration
Integrating the signal removes noise that creates error in the measurement. Slow
integration removes more noise than fast integration. Integration time can be
modified to reject 50 Hz and 60 Hz mains-power line noise.
Fast integration may be preferred at times to,
x
x
x
x
minimize time skew between successive measurements.
maximize throughput rate.
maximize life of the CR1000 power supply.
minimize polarization of polar sensors such as those for measuring
conductivity, soil moisture, or leaf wetness. Polarization may cause
measurement errors or sensor degradation.
improve accuracy of an LVDT measurement. The induced voltage in an LVDT
decays with time as current in the primary coil shifts from the inductor to the
series resistance; a long integration time may result in most of signal decaying
before the measurement is complete.
Single-Ended Measurements — Details
Related Topics:
‡Single-Ended Measurements — Overview (p. 65)
‡Single-Ended Measurements — Details (p. 307)
With reference to the figure Programmable Gain Input Amplifier (PGIA) (p. 306),
during a single-ended measurement, the high signal (H) is routed to V+. The low
signal (L) is automatically connected internally to signal ground with the low
signal tied to ground ( ) at the wiring panel. V+ corresponds to odd or even
307
Section 8. Operation
numbered SE terminals on the CR1000 wiring panel. The single-ended
configuration is used with the following CRBasic instructions:
x
x
x
x
x
x
x
x
VoltSE()
BrHalf()
BrHalf3W()
TCSE()
Therm107()
Therm108()
Therm109()
Thermistor()
Related Topics:
‡Differential Measurements — Overview (p. 66)
‡Differential Measurements — Details (p. 308)
Differential Measurements — Details
Using the figure Programmable Gain Input Amplifier (PGIA) (p. 306), for reference,
during a differential measurement, the high signal (H) is routed to V+ and the low
signal (L) is routed to V–.
An H terminal of an H/L terminal pair differential corresponds to V+. The L
terminal corresponds to V–. The differential configuration is used with the
following CRBasic instructions:
x
x
x
x
x
VoltDiff()
BrFull()
BrFull6W()
BrHalf4W()
TCDiff()
8.1.2.1.2 Voltage Measurement Limitations
Caution Sustained voltages in excess of r8.6 V applied to terminals configured
for analog input can temporarily corrupt all analog measurements.
Warning Sustained voltages in excess of r16 V applied to terminals configured
for analog input will damage CR1000 circuitry.
Voltage Ranges
Related Topicss:
‡9ROtage Measurements — Specifications
‡Voltage Measurements — Overview (p. 63)
‡Voltage Measurements — Details (p. 305)
In general, use the smallest fixed-input range that accommodates the full-scale
output of the sensor. This results in the best measurement accuracy and resolution.
The CR6 has fixed input ranges for voltage measurements and an auto-range to
automatically determine the appropriate input voltage range for a given
measurement. The table Analog Voltage Input Ranges and Options (p. 309) lists
these input ranges and codes.
308
Section 8. Operation
An approximate 9% range overhead exists on fixed input voltage ranges. In other
words, over-range on the r2500 mV input range occurs at approximately 2725
mV and –2725 mV. The CR1000 indicates a measurement over-range by
returning a NAN (not a number) for the measurement.
Automatic Range Finding
For signals that do not fluctuate too rapidly, range argument AutoRange allows
the CR1000 to automatically choose the voltage range. AutoRange makes two
measurements. The first measurement determines the range to use. It is made
with a 250 μs integration on the ±5000 mV range. The second measurement is
made using the range determined from the first. Both measurements use the
settling time entered in the SettlingTime parameter. Auto-ranging optimizes
resolution but takes longer than a measurement on a fixed range because of the
two-measurement sequences.
An auto-ranged measurement will return NAN ("not a number") if the voltage
exceeds the range picked by the first measurement. To avoid problems with a
signal on the edge of a range, AutoRange selects the next larger range when the
signal exceeds 90% of a range.
Use auto-ranging for a signal that occasionally exceeds a particular range, for
example, a type-J thermocouple measuring a temperature usually less than 476 qC
(r25 mV range) but occasionally as high as 500 qC (r250 mV range).
AutoRange should not be used for rapidly fluctuating signals, particularly signals
traversing multiple voltage ranges rapidly. The possibility exists that the signal
can change ranges between the internal range check and the actual measurement.
Table 55. Analog Voltage Input Ranges and Options
Range Code
Description
mV5000
measures voltages between ±5000 mV
1
measures voltages between ±2500 mV
2
measures voltages between ±250 mV
2
measures voltages between ±25 mV
2
measures voltages between ±7.5 mV
2
measures voltages between ±2.5 mV
mV2500
mV250
mV25
mV7_5
mV2_5
AutoRange
3
datalogger determines the most suitable range
1
Append with C to enable common-mode null / open-input detect and set excitation to full-scale
(~2700 mV) (Example: mV2500)
2
Append with C to enable common-mode null / open-input detect (Example: mV25C)
3
Append with C to enable common-mode null / open-LQSXWGHWHFWRQUDQJHV”“P9RUMXVW
common-mode null on ranges > ±250 mV (Example: AutoRangeC)
309
Section 8. Operation
Input Limits / Common-Mode Range
Related Topicss:
‡9ROWDJH0HDVXUHPHQWV— Specifications
‡Voltage Measurements — Overview (p. 63)
‡Voltage Measurements — Details (p. 305)
Note This section contains advanced information not required for normal
operation of the CR1000.
Summary
‡9ROWDJHLQSXWOLPLWVIRUPHDVXUHPHQWDUH“9GFInput Limits is the
specification listed in the section Specifications (p. 97).
‡&RPPRQ-mode range is not a fixed number. It varies with respect to the
magnitude of the input voltage.
‡7KH&5KDVIHDWXUHVWKDWKHOSPLWLJDWHVRPHRIWKHHIIHFWVRIVLJQDOVWKDW
exceed the Input Limits specification or the common-mode range.
With reference to the figure PGIA with Input-Signal Decomposition (p. 311), the
PGIA processes the voltage difference between V+ and V–. It ignores the
common-mode voltage, or voltages that are common to both inputs. The figure
shows the applied input voltage decomposed into a common-mode voltage (Vcm)
and the differential-mode component (Vdm) of a voltage signal. Vcm is the
average of the voltages on the V+ and V– inputs. So, Vcm = (V+ + V–)/2 or the
voltage remaining on the inputs when Vdm = 0. The total voltage on the V+ and
V– inputs is given as V+ = Vcm + Vdm/2, and V– = Vcm – Vdm/2, respectively.
The PGIA ignores or rejects common-mode voltages as long as voltages at V+
and V– are within the Input Limits specification, which for the CR6 is ±5 Vdc
relative to ground. Input voltages wherein V+ or V–, or both, are beyond the ±5
Vdc limit may suffer from undetected measurement errors. The Common-Mode
Range defines the range of common-mode voltages that are not expected to
induce undetected measurement errors. Common-Mode Range is different than
Input Limits when the differential mode voltage in non-negligible. The following
relationship is derived from the PGIA figure as:
Common-Mode Range = ±5 Vdc – |Vdm/2|.
The conclusion follows that the common-mode range is not a fixed number, but
instead decreases with increasing differential voltage. For differential voltages
that are small compared to the input limits, common-mode range is essentially
equivalent to Input Limits. Yet for a 5000 mV differential signal, the commonmode range is reduced to ±2.5 Vdc, whereas Input Limits are always ±5 Vdc.
Consequently, the term Input Limits is used to specify the valid voltage range of
the V+ and V– inputs into the PGIA.
310
Section 8. Operation
Figure 81. PGIA with Input-Signal Decomposition
–
8.1.2.1.3 Voltage Measurement Quality
Read More Consult the following technical papers at www.campbellsci.com/appnotes (http://www.campbellsci.com/app-notes) for in-depth treatments of several
topics addressing voltage measurement quality:
‡3UHYHQWLQJDQG$WWDFNLQJ0HDVXUHPHQW1RLVH3UREOHPV
‡%HQHILWVRI,QSXW5HYHUVDODQG([FLWDWLRQ5HYHUVDOIRU9ROWDJH0HDVXUHPHQWV
‡9ROWDJH0HDVXUHPHQW$FFXUDF\6HOI- Calibration, and Ratiometric
Measurements
‡(VWLPDWLQJ0HDVXUHPHQW$FFXUDF\IRU5DWLRPHWULF0HDVXUHPHQW,QVWUXFWLRQV
The following topics discuss methods of generally improving voltage
measurements. Related information for special case voltage measurements
(thermocouples (p. 327), current loops (p. 337), resistance (p. 337), and strain (p. 342)) is
located in sections for those measurements.
Single-Ended or Differential?
Deciding whether a differential or single-ended measurement is appropriate is
usually, by far, the most important consideration when addressing voltage
measurement quality. The decision requires trade-offs of accuracy and precision,
noise cancelation, measurement speed, available measurement hardware, and
fiscal constraints.
In broad terms, analog voltage is best measured differentially because these
measurements include noise reduction features, listed below, that are not included
in single-ended measurements.
x
Passive Noise Rejection
o
o
x
No voltage reference offset
Common-mode noise rejection, which filters capacitively coupled noise
Active Noise Rejection
o
Input reversal
Review Input and Excitation Reversal (p. 325) for details
Increases by twice the input reversal signal integration time
311
Section 8. Operation
Reasons for using single-ended measurements, however, include:
x
x
x
Not enough differential terminals available. Differential measurements use
twice as many H/L] terminals as do single-ended measurements.
Rapid sampling is required. Single-ended measurement time is about half
that of differential measurement time.
Sensor is not designed for differential measurements. Many Campbell
Scientific sensors are not designed for differential measurement, but the draw
backs of a single-ended measurement are usually mitigated by large
programmed excitation and/or sensor output voltages.
Sensors with a high signal-to-noise ratio, such as a relative-humidity sensor with a
full-scale output of 0 to 1000 mV, can normally be measured as single-ended
without a significant reduction in accuracy or precision.
Sensors with a low signal-to-noise ratio, such as thermocouples, should normally
be measured differentially. However, if the measurement to be made does not
require high accuracy or precision, such as thermocouples measuring brush-fire
temperatures, which can exceed 2500 °C, a single-ended measurement may be
appropriate. If sensors require differential measurement, but adequate input
terminals are not available, an analog multiplexer should be acquired to expand
differential input capacity. Refer to the appendix Analog Multiplexers (p. 646) for
information concerning available multiplexers.
Because a single-ended measurement is referenced to CR1000 ground, any
difference in ground potential between the sensor and the CR1000 will result in an
error in the measurement. For example, if the measuring junction of a copperconstantan thermocouple being used to measure soil temperature is not insulated,
and the potential of earth ground is 1 mV greater at the sensor than at the point
where the CR1000 is grounded, the measured voltage will be 1 mV greater than
the true thermocouple output, or report a temperature that is approximately 25 °C
too high. A common problem with ground-potential difference occurs in
applications wherein external, signal-conditioning circuitry is powered by the
same source as the CR1000, such as an ac mains power receptacle. Despite being
tied to the same ground, differences in current drain and lead resistance may result
in a different ground potential between the two instruments. So, as a precaution, a
differential measurement should be made on the analog output from an external
signal conditioner; differential measurements MUST be used when the low input
is known to be different from ground.
Electronic Noise
Electronic "noise" can cause significant error in a voltage measurement,
especially when measuring voltages less than 200 mV. So long as input
limitations are observed, the PGIA ignores voltages, including noise, that are
common to each side of a differential-input pair. This is the common-mode
voltage. Ignoring (rejecting or canceling) the common-mode voltage is an
essential feature of the differential input configuration that improves voltage
measurements.
Figure PGIA with Input-Signal Decomposition (p. 311), illustrates the commonmode component (Vcm) and the differential-mode component (Vdm) of a voltage
signal. Vcm is the average of the voltages on the V+ and V– inputs. So, Vcm =
312
Section 8. Operation
(V+ + V–)/2 or the voltage remaining on the inputs when Vdm = 0. The total
voltage on the V+ and V– inputs is given as V+ = Vcm + Vdm/2, and VL = Vcm –
Vdm/2, respectively.
Measurement Accuracy
Read More For an in-depth treatment of accuracy estimates, see the technical
paper Measurement Error Analysis available at www.campbellsci.com/app-notes
(http://www.campbellsci.com/app-notes).
Accuracy describes the difference between a measurement and the true value.
Many factors affect accuracy. This section discusses the affect percent-orreading, offset, and resolution have on the accuracy of the measurement of an
analog-voltage sensor signal. Accuracy is defined as follows:
accuracy = percent-of-reading + offset
where percents-of-reading are tabulated in the table Analog-Voltage Measurement
Accuracy (p. 313), and offsets are tabulated in the table Analog-Voltage
Measurement Offsets (p. 313).
Note Error discussed in this section and error-related specifications of the
CR1000 do not include error introduced by the sensor or by the transmission of
the sensor signal to the CR1000.
Table 56. Analog-Voltage Measurement Accuracy1
1
2
2
0 to 40 °C
–25 to 50 °C
–55 to 85 °C
±(0.06% of reading + offset)
±(0.12% of reading + offset)
±(0.18% of reading + offset)
Assumes the CR1000 is within factory specifications
Available only with purchased extended temperature option (-XT)
Table 57. Analog-Voltage Measurement Offsets
Differential Measurement
With Input Reversal
Differential Measurement
Without Input Reversal
Single-Ended
‡%DVLF5HVROXWLRQ
PV
‡%DVLF5HVROXWLRQPV
‡%DVLF5HVROXWLRQPV
Note — the value for Basic Resolution is found in the table Analog-Voltage Measurement
Resolution (p. 313).
Table 58. Analog-Voltage Measurement Resolution
Input
Voltage Range
(mV)
Differential
Measurement
With Input Reversal
(PV)
Basic Resolution
(PV)
r5000
667
1333
r2500
333
667
r250
25
3.33
6.7
313
Section 8. Operation
7.5
1.0
2.0
2.5
0.33
0.67
Note — see Specifications (p. 97) for a complete tabulation of measurement resolution
As an example, figure Voltage Measurement Accuracy Band Example (p. 314)
shows changes in accuracy as input voltage changes on the ±2500 input range.
Percent-of-reading is the principle component, so accuracy improves as input
voltage decreases. Offset is small, but could be significant in applications
wherein the sensor-signal voltage is very small, such as is encountered with
thermocouples.
Offset depends on measurement type and voltage-input range. Offsets equations
are tabulated in table Analog Voltage Measurement Offsets (p. 313). For example,
for a differential measurement with input reversal on the ±5000 mV input range,
the offset voltage is calculated as follows:
RIIVHW ‡%DVLF5HVROXWLRQ—9
‡—9—9
= 1001.5 μV
where Basic Resolution is the published resolution is taken from the table AnalogVoltage Measurement Resolution (p. 313).
Figure 82. Example voltage measurement accuracy band, including the
effects of percent of reading and offset, for a differential measurement
with input reversal at a temperature between 0 to 40 °C.
314
Section 8. Operation
Measurement Accuracy Example
The following example illustrates the effect percent-of-reading and offset have on
measurement accuracy. The effect of offset is usually negligible on large signals:
Example:
x
x
x
x
x
Sensor-VLJQDOYROWDJH§P9
CRBasic measurement instruction: VoltDiff()
Programmed input-voltage range (Range): mV2500 (±2500 mV)
Input measurement reversal (RevDiff): True
CR1000 circuitry temperature: 10 °C
Accuracy of the measurement is calculated as follows:
accuracy = percent-of-reading + offset
where
percent-of-UHDGLQJ P9‡“
= ±1.5 mV
and
RIIVHW ‡—9—9
= 1.00 mV
Therefore,
accuracy = ±1.5 mV + 1.00 mV
= ±2.5 mV
Integration
The CR1000 incorporates circuitry to perform an analog integration on voltages to
be measured prior to the A-to-D (p. 507) conversion. Integrating the the analog
signal removes noise that creates error in the measurement. Slow integration
removes more noise than fast integration. When the duration of the integration
matches the duration of one cycle of ac power mains noise, that noise is filtered
out. The table Analog Measurement Integration (p. 316) lists valid integration
duration arguments.
Faster integration may be preferred to achieve the following objectives:
x
x
x
x
x
Minimize time skew between successive measurements
Maximize throughput rate
Maximize life of the CR1000 power supply
Minimize polarization of polar sensors such as those for measuring
conductivity, soil moisture, or leaf wetness. Polarization may cause
measurement errors or sensor degradation.
Improve accuracy of an LVDT measurement. The induced voltage in an
LVDT decays with time as current in the primary coil shifts from the inductor
to the series resistance; a long integration may result in most of signal
decaying before the measurement is complete.
Read More See White Paper "Preventing and Attacking Measurement Noise
Problems" at www.campbellsci.com.
315
Section 8. Operation
The magnitude of the frequency response of an analog integrator is a SIN(x)/x
shape, which has notches (transmission zeros) occurring at 1/(integer multiples) of
the integration duration. Consequently, noise at 1/(integer multiples) of the
integration duration is effectively rejected by an analog integrator. If reversing
the differential inputs or reversing the excitation is specified, there are two
separate integrations per measurement; if both reversals are specified, there are
four separate integrations.
Table 59. Analog Measurement Integration
Integration Time (ms)
Integration Parameter
Argument
0 to 16000 μs
0 to 16000
250 μs is considered fast and
normally the minimum
16.667 ms
_60Hz
Filters 60 Hz noise
20 ms
_50Hz
Filters 50 Hz noise
Comments
Ac Power-Line Noise Rejection
Grid or mains power (50 or 60 Hz, 230 or 120 Vac) can induce electrical noise at
integer multiples of 50 or 60 Hz. Small analog voltage signals, such as
thermocouples and pyranometers, are particularly susceptible. CR1000 voltage
measurements can be programmed to reject (filter) 50 Hz or 60 Hz related noise.
Noise is rejected by using a signal integration time that is relative to the length of
the ac noise cycle, as illustrated in the figure Ac Power-Line Noise Rejection
Techniques (p. 316).
FIGURE. Ac power line noise rejection techniques -- 8 10 30
Figure 83. Ac-Power Noise-Rejection Techniques
The CR1000 rejects ac power line noise on all voltage ranges except mV5000 and
mV2500 by integrating the measurement over exactly one full ac cycle before A316
Section 8. Operation
to-D (p. 507) conversion as listed in table ac Noise Rejection on Small Signals (p. 317).
Table 60. Ac Noise Rejection on Small Signals1
1
Ac Power Line
Frequency
Measurement Integration
Duration
CRBasic Integration Code
60 Hz
16.667 ms
_60Hz
50 Hz
20 ms
_50Hz
Applies to all analog input voltage ranges except mV2500 and mV5000.
If rejecting ac-line noise when measuring with the 2500 mV (mV2500) and 5000
mV (mV5000) ranges, the CR1000 makes two fast measurements separated in
time by one-half line cycle. A 60 Hz half cycle is 8333 μs, so the second
measurement must start 8333 μs after the first measurement integration began.
The A-to-D conversion time is approximately 170 μs, leaving a maximum inputsettling time of approximately 8160 μs (8333 μs – 170 μs). If the maximum
input-settling time is exceeded, 60 Hz line-noise rejection will not occur. For 50
Hz rejection, the maximum input settling time is approximately 9830 μs (10,000
μs – 170 μs). The CR1000 does not prevent or warn against setting the settling
time beyond the half-cycle limit. Table ac Noise Rejection on Large Signals (p.
317) lists details of the half-cycle ac-power line-noise rejection technique.
Table 61. Ac Noise Rejection on Large Signals1
1
Ac-Power Line
Frequency
Measurement
Integration
Time
CRBasic
Integration
Code
Default
Settling
Time
Maximum
Recommended
60 Hz
ȝV‡
_60Hz
ȝV
ȝV
50 Hz
ȝV‡
_50Hz
ȝV
ȝV
Settling Time2
Applies to analog input voltage ranges mV2500 and mV5000.
2
Excitation time and settling time are equal in measurements requiring excitation. The CR1000 cannot excite VX excitation
terminals during A-to-D conversion. The one-half-cycle technique with excitation limits the length of recommended excitation and
settling time for the first measurement to one-half-cycle. The CR1000 does not prevent or warn against setting a settling time
beyond the one-half-cycle limit. For example, a settling time of up to 50000 μs can be programmed, but the CR1000 will execute
the measurement as follows:
1. CR1000 turns excitation on, waits 50000 μs, and then makes the first measurement.
2. During A-to-'&5WXUQVRIIH[FLWDWLRQIRU§—V
3. Excitation is switched on again for one-half cycle, then the second measurement is made.
Restated, when the CR1000 is programmed to use the half-cycle 50 Hz or 60 Hz rejection techniques, a sensor does not see a
continuous excitation of the length entered as the settling time before the second measurement — if the settling time entered is
greater than one-half cycle. This causes a truncated second excitation. Depending on the sensor used, a truncated second excitation
may cause measurement errors.
Signal-Settling Time
Settling time allows an analog voltage signal to settle closer to the true magnitude
prior to measurement. To minimize measurement error, signal settling is needed
when a signal has been affected by one or more of the following:
x
A small transient originating from the internal multiplexing that connects a
CR1000 terminal with measurement circuitry
317
Section 8. Operation
x
x
A relatively large transient induced by an adjacent excitation conductor on
the signal conductor, if present,because of capacitive coupling during a
bridge measurement
Dielectric absorption. 50 Hz or 60 Hz integrations require a relatively long
reset time of the internal integration capacitor before the next measurement.
The rate at which the signal settles is determined by the input settling-time
constant, which is a function of both the source resistance and fixed-input
capacitance (3.3 nfd) of the CR1000.
Rise and decay waveforms are exponential. Figure Input Voltage Rise and
Transient Decay (p. 318) shows rising and decaying waveforms settling closer to the
true signal magnitude, Vso. The SettlingTime parameter of an analog
measurement instruction allows tailoring of measurement instruction settling
times with 100 μs resolution up to 50000 μs.
Programmed settling time is a function of arguments placed in the SettlingTime
and Integ parameters of a measurement instruction. Argument combinations and
resulting settling times are listed in table CRBasic Measurement Settling Times (p.
318). Default settling times (those resulting when SettlingTime = 0) provide
sufficient settling in most cases. Additional settling time is often programmed
when measuring high-resistance (high-impedance) sensors or when sensors
connect to the input terminals by long leads.
Measurement time of a given instruction increases with increasing settling time.
For example, a 1 ms increase in settling time for a bridge instruction with input
reversal and excitation reversal results in a 4 ms increase in time for the CR1000
to perform the instruction.
Figure 84. Input-voltage rise and transient decay
Table 62. CRBasic Measurement Settling Times
318
SettlingTime
Argument
Integ
Argument
Settling Time
Resultant
0
250
450 μs
0
_50Hz
3 ms
0
_60Hz
3 ms
integer •100
integer
ȝVHQWHUHGLQSettlingTime
argument
1
Section 8. Operation
Table 62. CRBasic Measurement Settling Times
SettlingTime
Argument
1
Integ
Argument
Resultant
Settling Time
1
450 μs is the minimum settling time required to meet CR1000 resolution specifications.
Settling Errors
When sensors require long lead lengths, use the following general practices to
minimize settling errors:
x
x
x
x
Do not use wire with PVC-insulated conductors. PVC has a high dielectric
constant, which extends input settling time.
Where possible, run excitation leads and signal leads in separate shields to
minimize transients.
When measurement speed is not a prime consideration, additional time can be
used to ensure ample settling time. The settling time required can be
measured with the CR1000.
In difficult cases, settling error can be measured as described in section
Measuring Settling Time (p. 319).
Measuring Settling Time
Settling time for a particular sensor and cable can be measured with the CR1000.
Programming a series of measurements with increasing settling times will yield
data that indicate at what settling time a further increase results in negligible
change in the measured voltage. The programmed settling time at this point
indicates the settling time needed for the sensor / cable combination.
CRBasic example Measuring Settling Time (p. 319) presents CRBasic code to help
determine settling time for a pressure transducer using a high-capacitance
semiconductor. The code consists of a series of full-bridge measurements
(BrFull()) with increasing settling times. The pressure transducer is placed in
steady-state conditions so changes in measured voltage are attributable to settling
time rather than changes in pressure. Reviewing the section Programming (p. 122)
may help in understanding the CRBasic code in the example.
The first six measurements are shown in table First Six Values of Settling-Time
Data (p. 321). Each trace in figure Settling Time for Pressure Transducer (p. 321)
contains all twenty PT() mV/V values (left axis) for a given record number, along
with an average value showing the measurements as percent of final reading (right
axis). The reading has settled to 99.5% of the final value by the fourteenth
measurement, which is contained in variable PT(14). This is suitable accuracy for
the application, so a settling time of 1400 μs is determined to be adequate.
319
Section 8. Operation
CRBasic Example 64.
Measuring Settling Time
'This program example demonstrates the measurement of settling time using a single
'measurement instruction multiple times in succession. In this case, the program measures
'the temperature of the CR1000 wiring panel.
Public RefTemp 'Declare variable to receive instruction
BeginProg
Scan(1,Sec,3,0)
PanelTemp(RefTemp, 250) 'Instruction to make measurement
NextScan
EndProg measures the settling time of a sensor measured with a differential
'voltage measurement
Public PT(20)
'Variable to hold the measurements
DataTable(Settle,True,100)
Sample(20,PT(),IEEE4)
EndTable
BeginProg
Scan(1,Sec,3,0)
BrFull(PT(1),1,mV7.5,1,Vx1,2500,True,True,100, 250,1.0,0)
BrFull(PT(2),1,mV7.5,1,Vx1,2500,True,True,200, 250,1.0,0)
BrFull(PT(3),1,mV7.5,1,Vx1,2500,True,True,300, 250,1.0,0)
BrFull(PT(4),1,mV7.5,1,Vx1,2500,True,True,400, 250,1.0,0)
BrFull(PT(5),1,mV7.5,1,Vx1,2500,True,True,500, 250,1.0,0)
BrFull(PT(6),1,mV7.5,1,Vx1,2500,True,True,600, 250,1.0,0)
BrFull(PT(7),1,mV7.5,1,Vx1,2500,True,True,700, 250,1.0,0)
BrFull(PT(8),1,mV7.5,1,Vx1,2500,True,True,800, 250,1.0,0)
BrFull(PT(9),1,mV7.5,1,Vx1,2500,True,True,900, 250,1.0,0)
BrFull(PT(10),1,mV7.5,1,Vx1,2500,True,True,1000, 250,1.0,0)
BrFull(PT(11),1,mV7.5,1,Vx1,2500,True,True,1100, 250,1.0,0)
BrFull(PT(12),1,mV7.5,1,Vx1,2500,True,True,1200, 250,1.0,0)
BrFull(PT(13),1,mV7.5,1,Vx1,2500,True,True,1300, 250,1.0,0)
BrFull(PT(14),1,mV7.5,1,Vx1,2500,True,True,1400, 250,1.0,0)
BrFull(PT(15),1,mV7.5,1,Vx1,2500,True,True,1500, 250,1.0,0)
BrFull(PT(16),1,mV7.5,1,Vx1,2500,True,True,1600, 250,1.0,0)
BrFull(PT(17),1,mV7.5,1,Vx1,2500,True,True,1700, 250,1.0,0)
BrFull(PT(18),1,mV7.5,1,Vx1,2500,True,True,1800, 250,1.0,0)
BrFull(PT(19),1,mV7.5,1,Vx1,2500,True,True,1900, 250,1.0,0)
BrFull(PT(20),1,mV7.5,1,Vx1,2500,True,True,2000, 250,1.0,0)
CallTable Settle
NextScan
EndProg
320
Section 8. Operation
Figure 85. Settling Time for Pressure Transducer
Table 63. First Six Values of Settling-Time Data
TIMESTAMP
REC
PT(1)
PT(2)
PT(3)
PT(4)
PT(5)
PT(6)
Smp
Smp
Smp
Smp
Smp
Smp
1/3/2000 23:34
0
0.03638599
0.03901386
0.04022673
0.04042887
0.04103531
0.04123745
1/3/2000 23:34
1
0.03658813
0.03921601
0.04002459
0.04042887
0.04103531
0.0414396
1/3/2000 23:34
2
0.03638599
0.03941815
0.04002459
0.04063102
0.04042887
0.04123745
1/3/2000 23:34
3
0.03658813
0.03941815
0.03982244
0.04042887
0.04103531
0.04103531
1/3/2000 23:34
4
0.03679027
0.03921601
0.04022673
0.04063102
0.04063102
0.04083316
Open-Input Detect
Note Much of the information in the following section is highly technical and is
not necessary for the routine operation of the CR1000. The information is
included to foster a deeper understanding of the open-input detection feature of
the CR1000.
Summary
‡$QRSWLRQWRGHWHFWDQRSHQ-input, such as a broken sensor or loose connection,
is available in the CR1000.
‡7KHRSWLRQLVVHOHFWHGE\DSSHQGLQJDC to the Range code.
‡8VLQJWKLVRSWLRQWKHUHVXOWRIDPHDVXUHPHQWRQDQRSHQFRQQHFWLRQZLOOEH
NAN (not a number).
A useful option available to single-ended and differential measurements is the
detection of open inputs due to a broken or disconnected sensor wire. This
prevents otherwise undetectable measurement errors. Range codes appended with
C enable open-input detect for all input ranges except the r5000 mV input range
(see table Analog Voltage Input Ranges with CMN / OID (p. 309) ).
321
Section 8. Operation
Appending the Range code with a C results in a 50 μs internal connection of the
V+ input of the PGIA to a large over-voltage. The V– input is connected to
ground. Upon disconnecting the inputs, the true input signal is allowed to settle
and the measurement is made normally. If the associated sensor is connected, the
signal voltage is measured. If the input is open (floating), the measurement will
over-range since the injected over-voltage will still be present on the input, with
NAN as the result.
Range codes and applicable over-voltage magnitudes are found in the table
Range-Code Option C Over-Voltages (p. 322).
The C option may not work, or may not work well, in the following applications:
x
x
x
If the input is not a truly open circuit, such as might occur on a wet cut cable
end, the open circuit may not be detected because the input capacitor
discharges through external leakage to ground to a normal voltage within the
settling time of the measurement. This problem is worse when a long settling
time is selected, as more time is given for the input capacitors to discharge to
a "normal" level.
If the open circuit is at the end of a very long cable, the test pulse (300 mV)
may not charge the cable (with its high capacitance) up to a voltage that
generates NAN or a distinct error voltage. The cable may even act as an aerial
and inject noise which also might not read as an error voltage.
The sensor may "object" to the test pulse being connected to its output, even
for 100 μs. There is little or no risk of damage, but the sensor output may be
caused to temporarily oscillate. Programming a longer settling time in the
CRBasic measurement instruction to allow oscillations to decay before the Ato-D conversion may mitigate the problem.
Table 64. Range-Code Option C Over-Voltages
Input Range
Over-Voltage
r2.5 mV
r7.5 mV
r25 mV
r250 mV
300 mV
r2500 mV
C option with caveat
r mV
C option not available
1
1
C results in the H terminal being briefly connected to a voltage greater than 2500 mV, while the
L terminal is connected to ground. The resulting common-mode voltage is 1250 mV, which is not
adequate to null residual common-mode voltage, but is adequate to facilitate a type of open-input
detect. This requires inclusion of an If / Then / Else statement in the CRBasic program to test the
results of the measurement. For example:
‡7KHUHVXOWRIDVoltDiff() measurement using mV2500C as the Range code can be tested for a
result >2500 mV, which would indicate an open input.
‡7KHUHVXOWRIWKHBrHalf() measurement, X, using the mV2500C range code can be tested for
values >1. A result of X > 1 indicates an open input for the primary measurement, V1, where X =
V1/Vx and Vx is the excitation voltage. A similar strategy can be used with other bridge
measurements.
322
Section 8. Operation
Offset Voltage Compensation
Related Topics
‡Auto Calibration — Overview (p. 92)
‡Auto Calibration — Details (p. 344)
‡Auto-Calibration — Errors (p. 490)
‡Offset Voltage Compensation (p. 323)
‡Factory Calibration (p. 94)
‡Factory Calibration or Repair Procedure (p. 476)
Summary
Measurement offset voltages are unavoidable, but can be minimized.
Offset voltages originate with:
‡*URXQGFXUUHQWV
‡6HHEHFNHIIHFW
‡5HVLGXDOYROWDJHIURPDSUHYLRXVPHDVXUHPHQW
Remedies include:
‡&RQQHFWSRZHUJURXQGVWRSRZHUJURXQGWHUPLQDOVG)
‡8VHLnput reveral (RevDiff = True) with differential measurements
‡$XWRPDWLFRIIVHWFRPSHQVDWLRQIRUGLIIHUHQWLDOPHDVXUHPHQWVZKHQRevDiff =
False
‡$XWRPDWLFRIIVHWFRPSHQVDWLRQIRUVLQJOH-ended measurements when MeasOff
= False
‡%HWWHURIIVHWFRPSHQVation when MeasOff = True
‡([FLWDWLRQUHYHUVDORevEx = True)
‡/RQJHUVHWWOLQJWLPHV
Voltage offset can be the source of significant error. For example, an offset of 3
ȝ9RQDP9VLJQDOFDXVHVDQHUURURIRQO\EXWWKHVDPHRIIVHWRQ
a 0.25 mV signal causes an error of 1.2%. The primary sources of offset voltage
are ground currents and the Seebeck effect.
Single-ended measurements are susceptible to voltage drop at the ground terminal
caused by return currents from another device that is powered from the CR1000
wiring panel, such as another manufacturer's telecommunication modem, or a
sensor that requires a lot of power. Currents >5 mA are usually undesirable. The
error can be avoided by routing power grounds from these other devices to a
power ground G terminal on the CR1000 wiring panel, rather than using a signal
ground ( ) terminal. Ground currents can be caused by the excitation of
resistive-bridge sensors, but these do not usually cause offset error. These
currents typically only flow when a voltage excitation is applied. Return currents
associated with voltage excitation cannot influence other single-ended
measurements because the excitation is usually turned off before the CR1000
moves to the next measurement. However, if the CRBasic program is written in
such a way that an excitation terminal is enabled during an unrelated measurement
of a small voltage, an offset error may occur.
The Seebeck effect results in small thermally induced voltages across junctions of
dissimilar metals as are common in electronic devices. Differential measurements
are more immune to these than are single-ended measurements because of passive
voltage cancelation occurring between matched high and low pairs such as
1H/1L. So use differential measurements when measuring critical low-level
323
Section 8. Operation
voltages, especially those below 200 mV, such as are output from pyranometers
and thermocouples. Differential measurements also have the advantage of an
input reversal option, RevDiff. When RevDiff is True, two differential
measurements are made, the first with a positive polarity and the second reversed.
Subtraction of opposite polarity measurements cancels some offset voltages
associated with the measurement.
Single-ended and differential measurements without input reversal use an offset
voltage measurement with the PGIA inputs grounded. For differential
measurements without input reversal, this offset voltage measurement is
performed as part of the routine auto-calibration of the CR1000. Single-ended
measurement instructions VoltSE() and TCSe() MeasOff parameter determines
whether the offset voltage measured is done at the beginning of measurement
instruction, or as part of self-calibration. This option provides you with the
opportunity to weigh measurement speed against measurement accuracy. When
MeasOff = True, a measurement of the single-ended offset voltage is made at the
beginning of the VoltSE() instruction. When MeasOff = False, an offset voltage
measurement is made during self-calibration. For slowly fluctuating offset
voltages, choosing MeasOff = True for the VoltSE() instruction results in better
offset voltage performance.
Ratiometric measurements use an excitation voltage or current to excite the sensor
during the measurement process. Reversing excitation polarity also reduces offset
voltage error. Setting the RevEx parameter to True programs the measurement
for excitation reversal. Excitation reversal results in a polarity change of the
measured voltage so that two measurements with opposite polarity can be
subtracted and divided by 2 for offset reduction similar to input reversal for
differential measurements. Ratiometric differential measurement instructions
allow both RevDiff and RevEx to be set True. This results in four measurement
sequences:
x
x
x
x
positive excitation polarity with positive differential input polarity
negative excitation polarity with positive differential input polarity
positive excitation polarity with negative differential input polarity
positive excitation polarity then negative excitation differential input polarity
For ratiometric single-ended measurements, such as a BrHalf(), setting RevEx =
True results in two measurements of opposite excitation polarity that are
subtracted and divided by 2 for offset voltage reduction. For RevEx = False for
ratiometric single-ended measurements, an offset-voltage measurement is made
during the self-calibration.
When analog voltage signals are measured in series by a single measurement
instruction, such as occurs when VoltSE() is programmed with Reps = 2 or more,
measurements on subsequent terminals may be affected by an offset, the
magnitude of which is a function of the voltage from the previous measurement.
While this offset is usually small and negligible when measuring large signals,
significant error, or NAN, can occur when measuring very small signals. This
effect is caused by dielectric absorption of the integrator capacitor and cannot be
overcome by circuit design. Remedies include the following:
x
x
x
324
Program longer settling times
Use an individual instruction for each input terminal, the effect of which is to
reset the integrator circuit prior to integration.
Avoid preceding a very small voltage input with a very large voltage input in
Section 8. Operation
a measurement sequence if a single measurement instruction must be used.
The table Offset-Voltage Compensation Options (p. 325) lists some of the tools
available to minimize the effects of offset voltages.
Table 65. Offset Voltage Compensation Options
CRBasic
Measurement
Instruction
VoltDiff()
Input Reversal
(RevDiff =True)
Excitation
Reversal
(RevEx = True)
Measure
Offset During
Measurement
(MeasOff = True)
9
9
9
VoltSe()
TCDiff()
Measure Offset
During Background
Calibration
(RevDiff = False)
(RevEx = False)
(MeasOff = False)
9
9
9
9
TCSe()
9
BrHalf()
9
9
BrHalf3W()
9
9
Therm107()
9
9
Therm108()
9
9
Therm109()
9
9
BrHalf4W()
9
9
9
BrFull()
9
9
9
BrFull6W()
9
9
9
AM25T()
9
9
9
Input and Excitation Reversal
Reversing inputs (differential measurements) or reversing polarity of excitation
voltage (bridge measurements) cancels stray voltage offsets. For example, if 3
PV offset exists in the measurement circuitry, a 5 mV signal is measured as 5.003
mV. When the input or excitation is reversed, the second sub-measurement is –
4.997 mV. Subtracting the second sub-measurement from the first and then
dividing by 2 cancels the offset:
5.003 mV – (–4.997 mV) = 10.000 mV
10.000 mV / 2 = 5.000 mV
When the CR1000 reverses differential inputs or excitation polarity, it delays the
same settling time after the reversal as it does before the first sub-measurement.
So, there are two delays per measurement when either RevDiff or RevEx is used.
If both RevDiff and RevEx are True, four sub-measurements are performed;
positive and negative excitations with the inputs one way and positive and
negative excitations with the inputs reversed. The automatic procedure then is as
follows,
1. Switches to the measurement terminals
325
Section 8. Operation
2. Sets the excitation, and then settle, and then measure
3. Reverse the excitation, and then settles, and then measure
4. Reverse the excitation, reverse the input terminals, settle, measure
5. Reverse the excitation, settle, measure
There are four delays per measure. The CR1000 processes the four submeasurements into the reported measurement. In cases of excitation reversal,
excitation time for each polarity is exactly the same to ensure that ionic sensors do
not polarize with repetitive measurements.
Read More A white paper entitled "The Benefits of Input Reversal and
Excitation Reversal for Voltage Measurements" is available at
www.campbellsci.com.
Ground Reference Offset Voltage
When MeasOff is enabled (= True), the CR1000 measures the offset voltage of
the ground reference prior to each VoltSe() or TCSe() measurement. This offset
voltage is subtracted from the subsequent measurement.
From Background Calibration
If RevDiff, RevEx, or MeasOff is disabled (= False), offset voltage compensation
is continues to be automatically performed, albeit less effectively, by using
measurements from the automatic background calibration. Disabling RevDiff,
RevEx, or MeasOff speeds up measurement time; however, the increase in speed
comes at the cost of accuracy because of the following:
1 RevDiff, RevEx, and MeasOff are more effective.
2 Background calibrations are performed only periodically, so more time skew
occurs between the background calibration offsets and the measurements to
which they are applied.
Note When measurement duration must be minimal to maximize measurement
frequency, consider disabling RevDiff, RevEx, and MeasOff when CR1000
module temperatures and return currents are slow to change.
Time Skew Between Measurements
Time skew between consecutive voltage measurements is a function of settling
and integration times, A-to-D conversion, and the number entered into the Reps
parameter of the VoltDiff() or VoltSE() instruction. A close approximation is:
time skew = settling time + integration time + A-to-D conversion time1 +
reps2
1 A-to-D conversion time, which equals 15 μs.
2
If Reps > 1 (multiple measurements by a single instruction), no additional time
is required. If Reps = 1 in consecutive voltage instructions, add 15 μs per
instruction.
326
Section 8. Operation
8.1.2.2 Thermocouple Measurements —- Details
Related Topics:
‡7KHUPRFRXSOH0HDVXUHPHQWV— Details
‡7KHUPRFRXSOH0HDVXUHPHQWV— Instructions
Thermocouple measurements are special case voltage measurements.
Note Thermocouples are inexpensive and easy to use. However, they pose
several challenges to the acquisition of accurate temperature data, particularly
when using external reference junctions. Campbell Scientific strongly
encourages you to carefully evaluate the section Error Analysis (p. 327). An
introduction to thermocouple measurements is located in the section Hands-on
Exercise: Measuring a Thermocouple (p. 46).
The micro-volt resolution and low-noise voltage measurement capability of the
CR1000 is well suited for measuring thermocouples. A thermocouple consists of
two wires, each of a different metal or alloy, joined at one end to form the
measurement junction. At the opposite end, each lead connects to terminals of a
voltage measurement device, such as the CR1000. These connections form the
reference junction. If the two junctions (measurement and reference) are at
different temperatures, a voltage proportional to the difference is induced in the
wires. This phenomenon is known as the Seebeck effect. Measurement of the
voltage between the positive and negative terminals of the voltage-measurement
device provides a direct measure of the temperature difference between the
measurement and reference junctions. A third metal (e.g., solder or CR1000
terminals) between the two dissimilar-metal wires form parasitic-thermocouple
junctions, the effects of which cancel if the two wires are at the same temperature.
Consequently, the two wires at the reference junction are placed in close
proximity so they remain at the same temperature. Knowledge of the referencejunction temperature provides the determination of a reference-junction
compensation voltage, corresponding to the temperature difference between the
reference junction and 0qC. This compensation voltage, combined with the
measured thermocouple voltage, can be used to compute the absolute temperature
of the thermocouple junction. To facilitate thermocouple measurements, a
thermistor is integrated into the CR1000 wiring panel for measurement of the
reference junction temperature by means of the PanelTemp() instruction.
TCDiff() and TCSe() thermocouple instructions determine thermocouple
temperatures using the following sequence. First, the temperature (°C) of the
reference junction is determined. Next, a reference-junction compensation voltage
is computed based on the temperature difference between the reference junction
and 0qC. If the reference junction is the CR1000 analog-input terminals, the
temperature is conveniently measured with the PanelTemp() instruction. The
actual thermocouple voltage is measured and combined with the referencejunction compensation voltage. It is then used to determine the thermocouplejunction temperature based on a polynomial approximation of NIST thermocouple
calibrations.
8.1.2.2.1 Thermocouple Error Analysis
The error in the measurement of a thermocouple temperature is the sum of the
errors in the reference-junction temperature measurement plus the temperature-to327
Section 8. Operation
voltage polynomial fit error, the non-ideal nature of the thermocouple (deviation
from standards published in NIST Monograph 175), the thermocouple-voltage
measurement accuracy, and the voltage-to-temperature polynomial fit error
(difference between NIST standard and CR1000 polynomial approximations). The
discussion of errors that follows is limited to these errors in calibration and
measurement and does not include errors in installation or matching the sensor
and thermocouple type to the environment being measured.
Panel-Temperature Error
The panel-temperature thermistor (Betatherm 10K3A1A) is just under the panel in
the center of the two rows of analog input terminals. It has an interchangeability
specification of 0.1 °C for temperatures between 0 and 70 °C. Below freezing and
at higher temperatures, this specification is degraded. Combined with possible
errors in the completion-resistor measurement and the Steinhart and Hart equation
used to calculate the temperature from resistance, the accuracy of panel
temperature is estimated in figure Panel Temperature Error Summary (p. 329). In
summary, error is estimated at ± 0.1 °C over 0 to 40 °C, ± 0.3 °C from –25 to 50
°C, and ± 0.8 °C from –55 to 85 °C.
The error in the reference-temperature measurement is a combination of the error
in the thermistor temperature and the difference in temperature between the panel
thermistor and the terminals the thermocouple is connected to. The terminal strip
cover should always be used when making thermocouple measurements. It
insulates the terminals from drafts and rapid fluctuations in temperature as well as
conducting heat to reduce temperature gradients. In a typical installation where
the CR1000 is in a weather-tight enclosure not subject to violent swings in
temperature or uneven solar radiation loading, the temperature difference between
the terminals and the thermistor is likely to be less than 0.2 °C.
With an external driving gradient, the temperature gradients on the input panel
can be much worse. For example, the CR1000 was placed in a controlled
temperature chamber. Thermocouples in terminals at the ends and middle of each
analog terminal strip measured the temperature of an insulated aluminum bar
outside the chamber. The temperature of this bar was also measured by another
datalogger. Differences between the temperature measured by one of the
thermocouples and the actual temperature of the bar are due to the temperature
difference between the terminals the thermocouple is connected to and the
thermistor reference (the figures have been corrected for thermistor errors). Figure
Panel-Temperature Gradients (Low Temperature to High) (p. 329) shows the errors
when the chamber was changed from low temperature to high in approximately 15
minutes. Figure Panel-Temperature Gradients (High Temperature to Low) (p. 330)
shows the results when going from high temperature to low. During rapid
temperature changes, the panel thermistor will tend to lag behind terminal
temperature because it is mounted deeper in the CR1000.
328
Section 8. Operation
Figure 86. Panel-Temperature Error Summary
Figure 87. Panel-Temperature Gradients (low temperature to high)
329
Section 8. Operation
Figure 88. Panel-Temperature Gradients (high temperature to low)
Thermocouple Limits of Error
The standard reference that lists thermocouple output voltage as a function of
temperature (reference junction at 0°C) is the NIST (National Institute of
Standards and Technology) Monograph 175 (1993). ANSI (American National
Standards Institute) has established limits of error on thermocouple wire which is
accepted as an industry standard (ANSI MC 96.1, 1975). Table Limits of Error for
Thermocouple Wire (p. 331) gives the ANSI limits of error for standard and special
grade thermocouple wire of the types accommodated by the CR1000.
When both junctions of a thermocouple are at the same temperature, no voltage is
generated, a result of the law of intermediate metals. A consequence of this is that
a thermocouple cannot have an offset error; any deviation from a standard
(assuming the wires are each homogeneous and no secondary junctions exist) is
due to a deviation in slope. In light of this, the fixed temperature-limits of error
(e.g., ±1.0 qC for type T as opposed to the slope error of 0.75% of the
temperature) in the table above are probably greater than one would experience
when considering temperatures in the environmental range (i.e., the reference
junction, at 0qC, is relatively close to the temperature being measured, so the
absolute error — the product of the temperature difference and the slope error —
should be closer to the percentage error than the fixed error). Likewise, because
thermocouple calibration error is a slope error, accuracy can be increased when
the reference junction temperature is close to the measurement temperature. For
the same reason differential temperature measurements, over a small temperature
gradient, can be extremely accurate.
To quantitatively evaluate thermocouple error when the reference junction is not
fixed at 0°C limits of error for the Seebeck coefficient (slope of thermocouple
voltage vs. temperature curve) are needed for the various thermocouples. Lacking
this information, a reasonable approach is to apply the percentage errors, with
perhaps 0.25% added on, to the difference in temperature being measured by the
330
Section 8. Operation
thermocouple.
Table 66. Limits of Error for Thermocouple Wire (Reference
Junction at 0°C)
Limits of Error
Thermocouple
Temperature
Type
Range °C
Standard
T
–200 to 0
± 1.0 °C or 1.5%
0 to 350
± 1.0 °C or 0.75%
± 0.5 °C or 0.4%
J
0 to 750
± 2.2 °C or 0.75%
± 1.1 °C or 0.4%
E
–200 to 0
± 1.7 °C or 1.0%
0 to 900
± 1.7 °C or 0.5%
–200 to 0
± 2.2 °C or 2.0%
0 to 1250
± 2.2 °C or 0.75%
± 1.1 °C or 0.4%
R or S
0 to 1450
± 1.5 °C or 0.25%
± 0.6 °C or 0.1%
B
800 to 1700
± 0.5%
Not Established.
K
(Whichever is greater)
Special
± 1.0 °C or 0.4%
Thermocouple Voltage Measurement Error
Thermocouple outputs are extremely small — 10 to 70 μV per °C. Unless high
resolution input ranges are used when programming, the CR1000, accuracy and
sensitivity are compromised. Table Voltage Range for Maximum Thermocouple
Resolution (p. 331) lists high resolution ranges available for various thermocouple
types and temperature ranges. The following four example calculations of
thermocouple input error demonstrate how the selected input voltage range
impacts the accuracy of measurements. Figure Input Error Calculation (p. 332)
shows from where various values are drawn to complete the calculations. See
Measurement Accuracy for more information on measurement accuracy and
accuracy calculations.
When the thermocouple measurement junction is in electrical contact with the
object being measured (or has the possibility of making contact) a differential
measurement should be made to avoid ground looping.
Table 67. Voltage Range for Maximum Thermocouple Resolution
Reference temperature at 20°C
TC Type and
Temperature
Range (°C)
Temperature
Range (°C)
for ±2.5 mV
Input Range
Temperature
Range (°C)
for ±7.5 mV
Input Range
Temperature
Range (°C)
for ±25 mV
Input Range
Temperature
Range (°C)
for ±250 mV
Input Range
T: –270 to 400
–45 to 75
–270 to 180
–270 to 400
not used
E: –270 to 1000
–20 to 60
–120 to 130
–270 to 365
>365
K: –270 to 1372
–40 to 80
–270 to 200
–270 to 620
>620
J: –210 to 1200
–25 to 65
–145 to 155
–210 to 475
>475
B: –0 to 1820
0 to 710
0 to 1265
0 to 1820
not used
331
Section 8. Operation
Table 67. Voltage Range for Maximum Thermocouple Resolution
Reference temperature at 20°C
TC Type and
Temperature
Range (°C)
Temperature
Range (°C)
for ±2.5 mV
Input Range
Temperature
Range (°C)
for ±7.5 mV
Input Range
Temperature
Range (°C)
for ±25 mV
Input Range
Temperature
Range (°C)
for ±250 mV
Input Range
R: –50 to 1768
–50 to 320
–50 to 770
–50 to 1768
not used
S: –50 to 1768
–50 to 330
–50 to 820
–50 to 1768
not used
N: –270 to 1300
–80 to 105
–270 to 260
–270 to 725
>725
Figure 89. Input Error Calculation
Input Error Examples: Type T Thermocouple @ 45°C
These examples demonstrate that in the environmental temperature range, inputoffset error is much greater than input-gain error because a small input range is
used.
Conditions:
CR1000 module temperature, –25 to 50 °C
Temperature = 45 °C
332
Section 8. Operation
Reference temperature = 25 °C
Delta T (temperature difference) = 20 °C
Thermocouple output multiplier at 45 °C = 42.4 μV °C-1
7KHUPRFRXSOHRXWSXW ƒ&‡ μV °C-1 = 830.7 μV
Input range = ±2.5 mV
Error Calculations with Input Reversal = True
μV error = gain term + offset term
—9‡‡—9—9
= 0.997 μV + 2.01 μV
= 3.01 μV (= 0.071 °C)
Error Calculations with Input Reversal = False
μV Error = gain term + offset term
—9‡‡—9—9
= 0.997 μV + 4.01 μV
= 5.01 μV (= 0.12 °C)
Input Error Examples: Type K Thermocouple @ 1300°C
Error in the temperature due to inaccuracy in the measurement of the
thermocouple voltage increases at temperature extremes, particularly when the
temperature and thermocouple type require using the ±200|250 mV range. For
example, assume type K (chromel-alumel) thermocouples are used to measure
temperatures around 1300°C.
These examples demonstrate that at temperature extremes, input offset error is
much less than input gain error because the use of a larger input range is required.
Conditions
CR1000 module temperature, –25 to 50 °C
Temperature = 1300 °C
Reference temperature = 25 °C
Delta T (temperature difference) = 1275 °C
Thermocouple output multiplier at 1300 °C = 34.9 μV °C-1
7KHUPRFRXSOHRXWSXW ƒ&‡—9ƒ&-1 = 44500 μV
Input range = ±250 mV
Error Calculations with Input Reversal = True
μV error = gain term + offset term
= (44500 μV * 0.12%) + (1.5 * 66.7 μV + 1.0 μV)
= 53.4 μV + 101.0 μV
= 154 μV (= 4.41 °C)
333
Section 8. Operation
Error Calculations with Input Reversal = False
μV error = gain term + offset term
= (44500 μV * 0.12%) + (3 * 66.7 μV + 2.0 μV)
= 53.4 μV + 200 μV
= 7.25 μV (= 7.25 °C)
Ground Looping Error
When the thermocouple measurement junction is in electrical contact with the
object being measured (or has the possibility of making contact), a differential
measurement should be made to avoid ground looping.
Noise Error
The typical input noise on the ±2_5 mV range for a differential measurement with
PVLQWHJUDWLRQDQGLQSXWUHYHUVDOLVȝ95062QDW\SH-T
WKHUPRFRXSOHDSSUR[LPDWHO\ȝ9qC), this is 0.005qC.
Note This is an RMS value; some individual readings will vary by greater than
this.
Thermocouple Polynomial Error
NIST Monograph 175 gives high-order polynomials for computing the output
voltage of a given thermocouple type over a broad range of temperatures. To
speed processing and accommodate the CR1000 math and storage capabilities,
four separate 6th-order polynomials are used to convert from volts to temperature
over the range covered by each thermocouple type. The table Limits of Error on
CR1000 Thermocouple Polynomials (p. 334) gives error limits for the thermocouple
polynomials.
Table 68. Limits of Error on CR1000 Thermocouple Polynomials
TC
Type
T
J
E
334
Limits of Error °C
Relative to NIST
Standards
Range °C
–270
to
400
–270
to
–200
18 @ –270
–200
to
–100
±0.08
–100
to
100
±0.001
100
to
400
±0.015
–150
to
760
±0.008
–100
to
300
±0.002
–240
to
1000
–240
to
–130
±0.4
–130
to
200
±0.005
Section 8. Operation
Table 68. Limits of Error on CR1000 Thermocouple Polynomials
TC
Type
Limits of Error °C
Relative to NIST
Standards
Range °C
K
200
to
1000
±0.02
–50
to
1372
–50
to
950
±0.01
950
to
1372
±0.04
Reference-Junction Error
Thermocouple instructions TCDiff() and TCSe() include the parameter TRef to
incorporate the reference-junction temperature into the measurement. A referencejunction compensation voltage is computed from TRef as part of the
thermocouple instruction, based on the temperature difference between the
reference junction and 0 °C. The polynomials used to determine the referencejunction compensation voltage do not cover the entire thermocouple range, as
illustrated in tables Limits of Error on CR1000 Thermocouple Polynomials (p. 334)
and Reference-Temperature Compensation Range and Polynomial Error (p. 335).
Substantial errors in the reference junction compensation voltage will result if the
reference-junction temperature is outside of the polynomial-fit ranges given.
The reference-junction temperature measurement can come from a PanelTemp()
instruction or from any other temperature measurement of the reference junction.
The standard and extended (-XT) operating ranges for the CR1000 are –25 to 50
°C and –55 to 85 °C, respectively. These ranges also apply to the referencejunction temperature measurement using PanelTemp().
Two sources of error arise when the reference temperature is out of the
polynomial-fit range. The most significant error is in the calculated compensation
voltage; however, a small error is also created by non-linearities in the Seebeck
coefficient.
Table 69. Reference-Temperature Compensation Range and Error
1
1
TC Type
Range °C
Limits of Error °C
T
–100 to 100
± 0.001
E
–150 to 206
± 0.005
J
–150 to 296
± 0.005
K
–50 to 100
± 0.01
Relative to ITS-90 Standard in NIST Monograph 175
Thermocouple Error Summary
Errors in the thermocouple- and reference-temperature linearizations are
extremely small, and error in the voltage measurement is negligible.
The magnitude of the errors discussed in Error Analysis (p. 327) show that the
greatest sources of error in a thermocouple measurement are usually,
335
Section 8. Operation
x
x
The typical (and industry accepted) manufacturing error of thermocouple
wire
The reference temperature
The table Thermocouple Error Examples (p. 336) tabulates the relative magnitude of
these errors. It shows a worst case example where,
x
x
x
A temperature of 45 °C is measured with a type-T thermocouple and all
errors are maximum and additive:
Reference temperature is 25 °C, but it is indicating 25.1 °C.
The terminal to which the thermocouple is connected is 0.05 °C cooler than
the reference thermistor (0.15 °C error).
Table 70. Thermocouple Error Examples
Error: °C : % of Total Error
Source
Single Differential
250 μs Integration
Reversing Differential
50/60 Hz Rejection Integration
ANSI TC Error
(1°C)
TC Error 1% Slope
ANSI TC Error (1°C)
TC Error 1% Slope
Reference Temperature
0.15° : 11.5%
0.15° : 29.9%
0.15° : 12.2%
0.15° : 34.7%
TC Output
1.0° : 76.8%
0.2° : 39.8%
1.0° : 81.1%
0.2° : 46.3%
Voltage Measurement
0.12° : 9.2%
0.12° : 23.9%
0.07° : 5.7%
0.07° : 16.2%
Noise
0.03° : 2.3%
0.03° : 6.2%
0.01° : 0.8%
0.01° : 2.3%
Reference Linearization
0.001° : 0.1%
0.001° : 0.2%
0.001° : 0.1%
0.001° : 0.25%
Output Linearization
0.001° : 0.1%
0.001° : 0.2%
0.001° : 0.1%
0.001° : 0.25%
Total Error
1.302° : 100%
0.502° : 100%
1.232° : 100%
0.432° : 100%
8.1.2.2.2 Use of External Reference Junction
An external junction in an insulated box is often used to facilitate thermocouple
connections. It can reduce the expense of thermocouple wire when measurements
are made long distances from the CR1000. Making the external junction the
reference junction, which is preferable in most applications, is accomplished by
running copper wire from the junction to the CR1000. Alternatively, the junction
box can be used to couple extension-grade thermocouple wire to the
thermocouples, with the PanelTemp() instruction used to determine the reference
junction temperature.
Extension-grade thermocouple wire has a smaller temperature range than standard
thermocouple wire, but it meets the same limits of error within that range. One
situation in which thermocouple extension wire is advantageous is when the
junction box temperature is outside the range of reference junction compensation
provided by the CR1000. This is only a factor when using type K thermocouples,
since the upper limit of the reference compensation polynomial fit range is 100 °C
and the upper limit of the extension grade wire is 200 °C. With the other types of
thermocouples, the reference compensation polynomial-fit range equals or is
greater than the extension-wire range. In any case, errors can arise if temperature
gradients exist within the junction box.
Figure Diagram of a Thermocouple Junction Box (p. 337) illustrates a typical
336
Section 8. Operation
junction box wherein the reference junction is the CR1000. Terminal strips are a
different metal than the thermocouple wire. Thus, if a temperature gradient exists
between A and A' or B and B', the junction box will act as another thermocouple
in series, creating an error in the voltage measured by the CR1000. This
thermoelectric-offset voltage is also a factor when the junction box is used as the
reference junction. This offset can be minimized by making the thermal
conduction between the two points large and the distance small. The best solution
when extension-grade wire is being connected to thermocouple wire is to use
connectors which clamp the two wires in contact with each other.
When an external-junction box is also the reference junction, the points A, A', B,
and B' need to be very close in temperature (isothermal) to measure a valid
reference temperature, and to avoid thermoelectric-offset voltages. The box
should contain elements of high thermal conductivity, which will act to rapidly
equilibrate any thermal gradients to which the box is subjected. It is not necessary
to design a constant-temperature box. It is desirable that the box respond slowly to
external-temperature fluctuations. Radiation shielding must be provided when a
junction box is installed in the field. Care must also be taken that a thermal
gradient is not induced by conduction through the incoming wires. The CR1000
can be used to measure the temperature gradients within the junction box.
Figure 90. Diagram of a Thermocouple Junction Box
8.1.2.3 Current Measurements — Details
Related Topics:
‡Current Measurements — Overview (p. 66)
‡Current Measurements — Details (p. 337)
For a complete treatment of current-loop sensors (4 to 20 mA, for example),
please consult the following publications available at www.campbellsci.com/appnotes (http://www.campbellsci.com/app-notes):
x
x
Current Output Transducers Measured with Campbell Scientific Dataloggers
(2MI-B)
CURS100 100 Ohm Current Shunt Terminal Input Module
8.1.2.4 Resistance Measurements — Details
Related Topics:
‡5HVLVWDQFH0HDVXUHPHQWV— Specifications
‡Resistance Measurements — Overview (p. 67)
‡Resistance Measurements — Details (p. 337)
‡Resistance Measurements — Instructions (p. 551)
337
Section 8. Operation
By supplying a precise and known voltage to a resistive-bridge circuit and
measuring the returning voltage, resistance can be calculated.
CRBasic instructions for measuring resistance include:
BrHalf() — half-bridge
BrHalf3W() — three-wire half-bridge
BrHalf4W() — four-wire half-bridge
BrFull() — four-wire full-bridge
BrFull6W() — six-wire full-bridge
Read More Available resistive-bridge completion modules are listed in the
appendix Signal Conditioners (p. 647).
The CR1000 has five CRBasic bridge-measurement instructions. Table ResistiveBridge Circuits with Voltage Excitation (p. 338) shows ideal circuits and related
equations. In the diagrams, resistors labeled Rs are normally the sensors and those
labeled Rf are normally precision fixed (static) resistors. CRBasic example FourWire Full-Bridge Measurement (p. 340) lists CRBasic code that measures and
processes four-wire full-bridge circuits.
Offset voltages compensation applies to bridge measurements. In addition to
RevDiff and MeasOff parameters discussed in the section Offset Voltage
Compensation (p. 323), CRBasic bridge measurement instructions include the
RevEx parameter that provides the option to program a second set of
measurements with the excitation polarity reversed. Much of the offset error
inherent in bridge measurements is canceled out by setting RevDiff, MeasOff, and
RevEx to True.
Measurement speed can be slowed when using RevDiff, MeasOff, and RevEx.
When more than one measurement per sensor are necessary, such as occur with
the BrHalf3W(), BrHalf4W(), and BrFull6W instructions, input and excitation
reversal are applied separately to each measurement. For example, in the fourwire half-bridge (BrHalf4W()), when excitation is reversed, the differential
measurement of the voltage drop across the sensor is made with excitation at both
polarities and then excitation is again applied and reversed for the measurement of
the voltage drop across the fixed resistor. Further, the results of measurement
instructions (X) must be processed further to obtain the resistance value. This
processing requires additional program execution time.
338
Section 8. Operation
Table 71. Resistive-Bridge Circuits with Voltage Excitation
Resistive-Bridge Type and
Circuit Diagram
CRBasic Instruction and
Fundamental Relationship
Other
Relationships
1
Half-Bridge
CRBasic Instruction: BrHalf()
2
Fundamental Relationship :
1,3
Three-Wire Half-Bridge
CRBasic Instruction: BrHalf3W()
2
Fundamental Relationship :
1,3
Four-Wire Half-Bridge
CRBasic Instruction: BrHalf4W()
2
Fundamental Relationship :
339
Section 8. Operation
Table 71. Resistive-Bridge Circuits with Voltage Excitation
Resistive-Bridge Type and
Circuit Diagram
CRBasic Instruction and
Fundamental Relationship
1,3
Other
Relationships
These relationships apply to BrFull() and
BrFull6W().
Full-Bridge
CRBasic Instruction: BrFull()
2
Fundamental Relationship :
1
Six-Wire Full-Bridge
CRBasic Instruction: BrFull6W()
2
Fundamental Relationship :
1
2
3
340
Key: Vx = excitation voltage; V1, V2 = sensor return voltages; Rf = "fixed", "bridge" or "completion" resistor; Rs = "variable" or "sensing" resistor.
Where X = result of the CRBasic bridge measurement instruction with a multiplier of 1 and an offset of 0.
See the appendix Resistive Bridge Modules (p. 647) for a list of available terminal input modules to facilitate this measurement.
Section 8. Operation
CRBasic Example 6ϱ.
Four-Wire Full-Bridge Measurement and Processing
'This program example demonstrates the measurement and processing of a four-wire resistive
'full bridge. In this example, the default measurement stored in variable X is
'deconstructed to determine the resistance of the R1 resistor, which is the variable
'resistor in most sensors that have a four-wire full-bridge as the active element.
'Declare Variables
Public X
Public X1
Public R1
Public R2 = 1000
Public R3 = 1000
Public R4 = 1000
'Resistance of fixed resistor R2
'Resistance of fixed resistor R2
'Resistance of fixed resistor R4
'Main Program
BeginProg
Scan(500,mSec,1,0)
'Full Bridge Measurement:
BrFull(X,1,mV2500,1,Vx1,1,2500,True,True,0,_60Hz,1.0,0.0)
X1 = ((-1 * X) / 1000) + (R3 / (R3 + R4))
R1 = (R2 * (1 - X1)) / X1
NextScan
EndProg
8.1.2.4.1 Ac Excitation
Some resistive sensors require ac excitation. Ac excitation is defined as excitation
with equal positive (+) and negative (–) duration and magnitude. These include
electrolytic tilt sensors, soil moisture blocks, water-conductivity sensors, and
wetness-sensing grids. The use of single polarity dc excitation with these sensors
can result in polarization of sensor materials and the substance measured.
Polarization may cause erroneous measurement, calibration changes, or rapid
sensor decay.
Other sensors, for example, LVDTs (linear variable differential transformers),
require ac excitation because they require inductive coupling to provide a signal.
Dc excitation in an LVDT will result in no measurement.
CRBasic bridge-measurement instructions have the option to reverse polarity to
provide ac excitation by setting the RevEx parameter to True.
Note Take precautions against ground loops when measuring sensors that require
ac excitation. See Ground Looping in Ionic Measurements (p. 109).
8.1.2.4.2 Resistance Measurements — Accuracy
Read More Consult the following technical papers at www.campbellsci.com/appnotes (http://www.campbellsci.com/app-notes) for in-depth treatments of several
topics addressing voltage measurement quality:
‡3UHYHQWLQJDQG$WWDFNLQJ0HDVXUHPHQW1RLVH3UREOHPV
‡%HQHILWVRI,QSXW5HYHUVDODQG([FLWDWLRQ5HYHUVDOIRU9ROWDge Measurements
‡9ROWDJH0HDVXUHPHQW$FFXUDF\6HOI- Calibration, and Ratiometric
Measurements
‡(VWLPDWLQJ0HDVXUHPHQW$FFXUDF\IRU5DWLRPHWULF0HDVXUHPHQW,QVWUXFWLRQV
341
Section 8. Operation
Note Error discussed in this section and error-related specifications of the
CR1000 do not include error introduced by the sensor or by the transmission of
the sensor signal to the CR1000.
The accuracy specifications for ratiometric-resistance measurements are
summarized in the tables Ratiometric-Resistance Measurement Accuracy (p. 342).
Table 72. Ratiometric-Resistance Measurement Accuracy
–25 to 50 °C
1
±(0.04% of voltage measurement + offset)
1
Voltage measurement is variable V1 or V2 in the table Resistive-Bridge Circuits with Voltage
Excitation (p. 338). Offset is the same as that for simple analog-voltage measurements. See the
table Analog-Voltage Measurement Offsets (p. 313).
Assumptions that support the ratiometric-accuracy specification include:
x
x
x
CR1000 is within factory calibration specification.
Excitation voltages less than 1000 mV are reversed during the excitation
phase of the measurement.
Effects due to the following are not included in the specification:
o
o
o
Bridge-resistor errors
Sensor noise
Measurement noise
For a tighter treatment of the accuracy of ratiometric measurements, consult the
technical paper Estimating Measurement Accuracy for Ratiometric Measurement
Instructions., which should be available at www.campbellsci.com/app-notes
(http://www.campbellsci.com/app-notes) in June of 2015.
8.1.2.5 Strain Measurements — Details
Related Topics:
‡Strain Measurements — Overview (p. 68)
‡Strain Measurements — Details (p. 342)
‡FieldCalStrain() Examples (p. 223)
A principal use of the four-wire full bridge is the measurement of strain gages in
structural stress analysis. StrainCalc() calculates microstrain (Pİ from the
formula for the particular strain bridge configuration used. All strain gages
supported by StrainCalc() use the full-bridge schematic. In strain-gage parlance,
'quarter-bridge', 'half-bridge' and 'full-bridge' refer to the number of active
elements in the full-bridge schematic. In other words, a quarter-bridge strain gage
has one active element, a half-bridge has two, and a full-bridge has four.
StrainCalc() requires a bridge-configuration code. The table StrainCalc()
Instruction Equations (p. 343) shows the equation used by each configuration code.
Each code can be preceded by a dash (-). Use a code without the dash when the
bridge is configured so the output decreases with increasing strain. Use a dashed
code when the bridge is configured so the output increases with increasing strain.
In the equations in table StrainCalc() Instruction Equations (p. 343), a dashed code
342
Section 8. Operation
sets the polarity of Vr to negative.
Table 73. StrainCalc() Instruction Equations
StrainCalc()
BrConfig Code
Configuration
Quarter-bridge strain gage:
1
Half-bridge strain gage. One gage parallel to strain, the other at 90° to
strain.
2
Half-bridge strain gage. One gage parallel to + , the other parallel to :
3
Full-bridge strain gage. Two gages parallel to + , the other two parallel
to - :
4
Full-bridge strain gage. Half the bridge has two gages parallel to + and
- , and the other half to +
and :
5
Full-bridge strain gage. Half the bridge has two gages parallel to + and
, and the other half to and + :
6
where:
x
x
x
x
: Poisson's Ratio (0 if not applicable)
GF: Gage Factor
Vr: 0.001 (Source-Zero) if BRConfig code is positive (+)
Vr: –0.001 (Source-Zero) if BRConfig code is negative (–)
and where:
x
x
"source": the result of the full-EULGJHPHDVXUHPHQW; ‡91 / Vx) when
multiplier = 1 and offset = 0.
"zero": gage offset to establish an arbitrary zero (see FieldCalStrain() in
FieldCal() Examples (p. 213) ).
343
Section 8. Operation
StrainCalc Example: See FieldCalStrain() Examples (p. 223)
8.1.2.6 Auto-Calibration — Details
Related Topics
‡Auto Calibration — Overview (p. 92)
‡Auto Calibration — Details (p. 344)
‡Auto-Calibration — Errors (p. 490)
‡Offset Voltage Compensation (p. 323)
‡Factory Calibration (p. 94)
‡Factory Calibration or Repair Procedure (p. 476)
The CR1000 auto-calibrates to compensate for changes caused by changing
operating temperatures and aging. With auto-calibration disabled, measurement
accuracy over the operational temperature range is specified as less accurate by a
factor of 10. That is, over the extended temperature range of –40 °C to 85 qC, the
accuracy specification of r0.12% of reading can degrade to r1% of reading with
auto-calibration disabled. If the temperature of the CR1000 remains the same,
there is little calibration drift if auto-calibration is disabled. Auto-calibration can
become disabled when the scan rate is too small. It can be disabled by the
CRBasic program when using the Calibrate() instruction.
Note The CR1000 is equipped with an internal voltage reference used for
calibration. The voltage reference should be periodically checked and recalibrated by Campbell Scientific for applications with critical analog voltage
measurement requirements. A minimum two-year recalibration cycle is
recommended.
Unless a Calibrate() instruction is present, the CR1000 automatically autocalibrates during spare time in the background as an automatic slow sequence (p.
157) with a segment of the calibration occurring every four seconds. If there is
insufficient time to do the background calibration because of a scan-consuming
user program, the CR1000 will display the following warning at compile time:
Warning: Background calibration is disabled.
8.1.2.6.1 Auto Calibration Process
The composite transfer function of the PGIA (p. 306) and A-to-D (p. 507) converter of
the CR1000 is described by the following equation:
&28176 *‡9LQ%
where COUNTS is the result from an A-to-D conversion, G is the voltage gain for
a given input range, Vin is the input voltage connected to V+ and V–, and B is the
internally measured offset voltage.
Automatic self-calibration calibrates only the G and B values necessary to run a
given CRBasic program, resulting in a program dependent number of selfcalibration segments ranging from a minimum of 6 to a maximum of 91. A
typical number of segments required in self-calibration is 20 for analog ranges and
one segment for the wiring-panel temperature measurement, totaling 21 segments.
6RVHJPHQWV‡VVHJPHQW VSHUFRPSOHWHVHOI-calibration. The
344
Section 8. Operation
worst-FDVHLVVHJPHQWV‡VVHJPHQW VSHUFRPSOHWHVHOI-calibration.
During instrument power-up, the CR1000 computes calibration coefficients by
averaging ten complete sets of self-calibration measurements. After power up,
newly determined G and B values are low-pass filtered as follows:
1H[WB9DOXH ‡QHZYDOXH‡ROGYDOXH
This results in the following settling percentages:
x
x
x
x
x
20% for 1 new value,
49% for 3 new values
67% for 5 new values
89% for 10 new values
96% for 14 new values
If this rate of update is too slow, the Calibrate() instruction can be used. The
Calibrate() instruction computes the necessary G and B values every scan
without any low-pass filtering.
For a VoltSe() instruction, B is determined as part of self-calibration only if the
parameter MeasOff = 0. An exception is B for VoltSe() on the r2500 input range
with a 250 Ps integration, which is always determined in self-calibration for use
internally. For a VoltDiff() instruction, B is determined as part of self-calibration
only if the parameter RevDiff = 0.
VoltSe() and VoltDiff() instructions, on a given input range with the same
integration durations, use the same G values but different B values. The six inputvoltage ranges (±5000 mV, ±2500 mV, ±250 mV, and ±25 mV), in combination
with the three most common integration durations (250 Ps, 50 Hz half-cycle, and
60 Hz half-cycle) result in a maximum of 18 different gains (G), and 18 offsets for
VoltSe() measurements (B), and 18 offsets for VoltDiff() measurements (B) to be
determined during CR1000 self-calibration (maximum of 54 values). These
values can be viewed in the Status table, with entries identified as listed in table
Status Table Calibration Entries (p. 346).
Automatic self-calibration can be overridden with the Calibrate() instruction,
which forces a calibration for each execution, and does not employ low-pass
filtering on the newly determined G and B values. The Calibrate() instruction
has two parameters: CalRange and Dest. CalRange determines whether to
calibrate only the necessary input ranges for a given CRBasic program (CalRange
= 0) or to calibrate all input ranges (CalRange 7KHDest parameter should
be of sufficient dimension for all returned G and B values, which is a minimum of
two for the automatic self-calibration of VoltSE() including B (offset) for the
±2500 mV input range with first 250 μs integration, and a maximum of 54 for all
input-voltage ranges used and possible integration durations.
An example use of the Calibrate() instruction programmed to calibrate all input
ranges is given in the following CRBasic code snip:
'Calibrate(Dest,Range)
Calibrate(cal(1),true)
where Dest is an array of 54 variables, and Range z 0 to calibrate all input ranges.
Results of this command are listed in the table Calibrate() Instruction Results (p.
347).
345
Section 8. Operation
Table 74. Auto Calibration Gains and Offsets
Status Table
Element
346
Descriptions of Status Table Elements
Differential (Diff)
Single-Ended (SE)
Offset or Gain
±mV Input
Range
Integration
CalGain(1)
Gain
5000
250 ms
CalGain(2)
Gain
2500
250 ms
CalGain(3)
Gain
250
250 ms
CalGain(4)
Gain
25
250 ms
CalGain(5)
Gain
7.5
250 ms
CalGain(6)
Gain
2.5
250 ms
CalGain(7)
Gain
5000
60 Hz Rejection
CalGain(8)
Gain
2500
60 Hz Rejection
CalGain(9)
Gain
250
60 Hz Rejection
CalGain(10)
Gain
25
60 Hz Rejection
CalGain(11)
Gain
7.5
60 Hz Rejection
CalGain(12)
Gain
2.5
60 Hz Rejection
CalGain(13)
Gain
5000
50 Hz Rejection
CalGain(14)
Gain
2500
50 Hz Rejection
CalGain(15)
Gain
250
50 Hz Rejection
CalGain(16)
Gain
25
50 Hz Rejection
CalGain(17)
Gain
7.5
50 Hz Rejection
CalGain(18)
Gain
2.5
50 Hz Rejection
CalSeOffset(1)
SE
Offset
5000
250 ms
CalSeOffset(2)
SE
Offset
2500
250 ms
CalSeOffset(3)
SE
Offset
250
250 ms
CalSeOffset(4)
SE
Offset
25
250 ms
CalSeOffset(5)
SE
Offset
7.5
250 ms
CalSeOffset(6)
SE
Offset
2.5
250 ms
CalSeOffset(7)
SE
Offset
5000
60 Hz Rejection
CalSeOffset(8)
SE
Offset
2500
60 Hz Rejection
CalSeOffset(9)
SE
Offset
250
60 Hz Rejection
CalSeOffset(10)
SE
Offset
25
60 Hz Rejection
CalSeOffset(11)
SE
Offset
7.5
60 Hz Rejection
CalSeOffset(12)
SE
Offset
2.5
60 Hz Rejection
CalSeOffset(13)
SE
Offset
5000
50 Hz Rejection
CalSeOffset(14)
SE
Offset
2500
50 Hz Rejection
CalSeOffset(15)
SE
Offset
250
50 Hz Rejection
Section 8. Operation
Table 74. Auto Calibration Gains and Offsets
Descriptions of Status Table Elements
Status Table
Element
Differential (Diff)
Single-Ended (SE)
Offset or Gain
±mV Input
Range
Integration
CalSeOffset(16)
SE
Offset
25
50 Hz Rejection
CalSeOffset(17)
SE
Offset
7.5
50 Hz Rejection
CalSeOffset(18)
SE
Offset
2.5
50 Hz Rejection
CalDiffOffset(1)
Diff
Offset
5000
250 ms
CalDiffOffset(2)
Diff
Offset
2500
250 ms
CalDiffOffset(3)
Diff
Offset
250
250 ms
CalDiffOffset(4)
Diff
Offset
25
250 ms
CalDiffOffset(5)
Diff
Offset
7.5
250 ms
CalDiffOffset(6)
Diff
Offset
2.5
250 ms
CalDiffOffset(7)
Diff
Offset
5000
60 Hz Rejection
CalDiffOffset(8)
Diff
Offset
2500
60 Hz Rejection
CalDiffOffset(9)
Diff
Offset
250
60 Hz Rejection
CalDiffOffset(10)
Diff
Offset
25
60 Hz Rejection
CalDiffOffset(11)
Diff
Offset
7.5
60 Hz Rejection
CalDiffOffset(12)
Diff
Offset
2.5
60 Hz Rejection
CalDiffOffset(13)
Diff
Offset
5000
50 Hz Rejection
CalDiffOffset(14)
Diff
Offset
2500
50 Hz Rejection
CalDiffOffset(15)
Diff
Offset
250
50 Hz Rejection
CalDiffOffset(16)
Diff
Offset
25
50 Hz Rejection
CalDiffOffset(17)
Diff
Offset
7.5
50 Hz Rejection
CalDiffOffset(18)
Diff
Offset
2.5
50 Hz Rejection
Table 75. Calibrate() Instruction Results
Array
Cal()
Element
Descriptions of Array Elements
Typical Value
Differential (Diff)
Single-Ended (SE)
Offset or Gain
±mV Input
Range
Integration
1
SE
Offset
5000
250 ms
±5 LSB
2
Diff
Offset
5000
250 ms
±5 LSB
Gain
5000
250 ms
–1.34 mV/LSB
3
4
SE
Offset
2500
250 ms
±5 LSB
5
Diff
Offset
2500
250 ms
±5 LSB
Gain
2500
250 ms
–0.67 mV/LSB
6
7
SE
Offset
250
250 ms
±5 LSB
8
Diff
Offset
250
250 ms
±5 LSB
Gain
250
250 ms
–0.067 mV/LSB
9
347
Section 8. Operation
Table 75. Calibrate() Instruction Results
Array
Cal()
Element
Descriptions of Array Elements
Offset or Gain
±mV Input
Range
Integration
10
SE
Offset
25
250 ms
±5 LSB
11
Diff
Offset
25
250 ms
±5 LSB
Gain
25
250 ms
–0.0067 mV/LSB
12
13
SE
Offset
7.5
250 ms
±10 LSB
14
Diff
Offset
7.5
250 ms
±10 LSB
Gain
7.5
250 ms
–0.002 mV/LSB
15
16
SE
Offset
2.5
250 ms
±20 LSB
17
Diff
Offset
2.5
250 ms
±20 LSB
Gain
2.5
250 ms
–0.00067 mV/LSB
19
SE
Offset
5000
60 Hz Rejection
±5 LSB
20
Diff
Offset
5000
60 Hz Rejection
±5 LSB
Gain
5000
60 Hz Rejection
–0.67 mV/LSB
18
21
22
SE
Offset
2500
60 Hz Rejection
±5 LSB
23
Diff
Offset
2500
60 Hz Rejection
±5 LSB
Gain
2500
60 Hz Rejection
–0.34 mV/LSB
24
25
SE
Offset
250
60 Hz Rejection
±5 LSB
26
Diff
Offset
250
60 Hz Rejection
±5 LSB
Gain
250
60 Hz Rejection
–0.067 mV/LSB
27
28
SE
Offset
25
60 Hz Rejection
±5 LSB
29
Diff
Offset
25
60 Hz Rejection
±5 LSB
Gain
25
60 Hz Rejection
–0.0067 mV/LSB
7.5
60 Hz Rejection
±10 LSB
30
31
SE
Offset
32
Diff
Offset
7.5
60 Hz Rejection
±10 LSB
Gain
7.5
60 Hz Rejection
–0.002 mV/LSB
33
34
SE
Offset
2.5
60 Hz Rejection
±20 LSB
35
Diff
Offset
2.5
60 Hz Rejection
±20 LSB
Gain
2.5
60 Hz Rejection
–0.00067 mV/LSB
36
37
SE
Offset
5000
50 Hz Rejection
±5 LSB
38
Diff
Offset
5000
50 Hz Rejection
±5 LSB
Gain
5000
50 Hz Rejection
–0.67 mV/LSB
39
40
SE
Offset
2500
50 Hz Rejection
±5 LSB
41
Diff
Offset
2500
50 Hz Rejection
±5 LSB
Gain
2500
50 Hz Rejection
–0.34 mV/LSB
Offset
250
50 Hz Rejection
±5 LSB
42
43
348
Typical Value
Differential (Diff)
Single-Ended (SE)
SE
Section 8. Operation
Table 75. Calibrate() Instruction Results
Array
Cal()
Element
44
Descriptions of Array Elements
Typical Value
Differential (Diff)
Single-Ended (SE)
Offset or Gain
±mV Input
Range
Integration
Diff
Offset
250
50 Hz Rejection
±5 LSB
Gain
250
50 Hz Rejection
–0.067 mV/LSB
45
46
SE
Offset
25
50 Hz Rejection
±5 LSB
47
Diff
Offset
25
50 Hz Rejection
±5 LSB
Gain
25
50 Hz Rejection
–0.0067 mV/LSB
48
49
SE
Offset
7.5
50 Hz Rejection
±10 LSB
50
Diff
Offset
7.5
50 Hz Rejection
±10 LSB
Gain
7.5
50 Hz Rejection
–0.002 mV/LSB
51
52
SE
Offset
2.5
50 Hz Rejection
±20 LSB
53
Diff
Offset
2.5
50 Hz Rejection
±20 LSB
Gain
2.5
50 Hz Rejection
–0.00067 mV/LSB
54
8.1.3
Pulse Measurements — Details
Related Topics:
‡3XOVH0HDVXUHPHQWV— Specifications
‡Pulse Measurements — Overview (p. 68)
‡Pulse Measurements — Details (p. 349)
‡Pulse Measurements — Instructions (p. 553)
Read More Review the PULSE COUNTERS (p. 349) and Pulse on C Terminals
sections in CR1000 Specifications (p. 97). Review pulse measurement programming
in CRBasic Editor Help for the PulseCount() and TimerIO() instructions.
Note Peripheral devices are available from Campbell Scientific to expand the
number of pulse-input channels measured by the CR1000. Refer to the appendix
Measurement and Control Peripherals Lists (p. 366) for more information.
The figure Pulse-Sensor Output-Signal Types (p. 69) illustrates pulse signal types
measurable by the CR1000:
x
x
x
low-level ac
high-frequency
switch-closure
The figure Switch-Closure Schematic (p. 350) illustrates the basic internal circuit
and the external connections of a switch-closure pulse sensor. The table Pulse
Measurements: Terminals and Programming (p. 351) summarizes available
measurements, terminals available for those measurements, and the CRBasic
instructions used. The number of terminals configurable for pulse input is
determined from the table CR1000 Terminal Definitions (p. 76).
349
Section 8. Operation
Figure 91. Pulse-Sensor Output-Signal Types
Figure 92. Switch-Closure Pulse Sensor
350
Section 8. Operation
Figure 93. Terminals Configurable for Pulse Input
Table 76. Pulse Measurements:, Terminals and Programming
C
Terminals
Low-level ac, counts
9
Low-level ac, Hz
9
Low-level ac, running average
9
High frequency, counts
9
9
High frequency, Hz
9
9
High frequency, running average
9
9
Switch closure, counts
9
9
Switch closure, Hz
9
9
Switch closure, running average
9
9
Calculated period
9
Calculated frequency
9
Time from edge on previous port
9
Time from edge on port 1
9
Count of edges
9
Pulse count, period
9
Pulse count, frequency
9
CRBasic
Instruction
PulseCount()
P
Terminals
TimerIO()
Measurement
351
Section 8. Operation
8.1.3.1 Pulse Measurement Terminals
P Terminals
x
Input voltage range = –20 to 20 V
If pulse input voltages exceed r20 V, third-party external-signal conditioners
should be employed. Contact a Campbell Scientific application engineer if
assistance is needed. Under no circumstances should voltages greater than 50 V
be measured.
C Terminals
x
Input voltage range = –8 to 16 Vdc
C terminals configured for pulse input have a small 25 ns input RC-filter time
constant between the terminal block and the CMOS input buffer, which allows for
high-frequency pulse measurements up to 250 kHz and edge counting up to 400
kHz. The CMOS input EXIIHUUHFRJQL]HVLQSXWV•9DVEHLQJKLJKDQGLQSXWV
”9DVEHLQJORZ
Open-collector (bipolar transistors) or open-drain (MOSFET) sensors are
typically measured as frequency sensors. C terminals can be conditioned for open
collector or open drain with an external pull-up resistor as shown in figure Using
a Pull-up Resistor on C terminals. The pull-up resistor counteracts an internal 100
NȍSXOO-down resistor, allowing inputs to be pulled to >3.8 V for reliable
measurements.
8.1.3.2 Low-Level Ac Measurements — Details
Related Topics:
‡Low-Level Ac Input Modules — Overview (p. 367)
‡Low-Level Ac Measurements — Details (p. 352)
‡Pulse Input Modules — Lists (p. 646)
Low-level ac (sine-wave) signals can be measured on P terminals. Sensors that
commonly output low-level ac include:
x
Ac generator anemometers
Measurements include the following:
x
x
x
Counts
Frequency (Hz)
Running average
Rotating magnetic-pickup sensors commonly generate ac voltage ranging from
thousandths of volts at low-rotational speeds to several volts at high-rotational
speeds. Terminals configured for low-level ac input have in-line signal
conditioning for measuring signals ranging from 20 mV RMS (r28 mV peak-topeak) to 14 V RMS (r20 V peak-to-peak).
352
Section 8. Operation
P Terminals
x
Maximum input frequency is dependent on input voltage:
o
o
o
o
x
1.0 to 20 Hz at 20 mV RMS
0.5 to 200 Hz at 200 mV RMS
0.3 to 10 kHz at 2000 mV RMS
0.3 to 20 kHz at 5000 mV RMS
CRBasic instruction: PulseCount()
Internal ac coupling is used to eliminate dc-offset voltages of up to r0.5 Vdc.
C Terminals
Low-level ac signals cannot be measured directly by C terminals. Refer to the
appendix Pulse Input Modules List (p. 646) for information on peripheral terminal
expansion modules available for converting low-level ac signals to square-wave
signals.
8.1.3.3 High-Frequency Measurements
High-frequency (square-wave) signals can be measured on P or C terminals.
Common sensors that output high-frequency include:
x
x
Photo-chopper anemometers
Flow meters
Measurements include counts, frequency in hertz, and running average. Refer to
the section Frequency Resolution (p. 353) for information about how the resolution
of a frequency measurement can be different depending on whether the
measurement is made with the PulseCount() or TimerIO() instruction.
x
P Terminals
x
x
Maximum input frequency = 250 kHz
CRBasic instructions: PulseCount()
High-frequency pulse inputs are routed to an inverting CMOS input buffer with
input hysteresis. The CMOS input buffer is at output 0 level with inputs t 2.2 V
and at output 1 level with inputs d 0.9 V. An internal 100 k: resistor is
automatically connected to the terminal to pull it up to 5 Vdc. This pull-up
resistor accommodates open-collector (open-drain) output devices.
C Terminals
x
x
Maximum input frequency = <1 kHz
CRBasic instructions: PulseCount(), TimerIO()
8.1.3.3.1 Frequency Resolution
Resolution of a frequency measurement made with the PulseCount() instruction
is calculated as
353
Section 8. Operation
where
FR = resolution of the frequency measurement (Hz)
S = scan interval of CRBasic program
Resolution of a frequency measurement made with the TimerIO() instruction is
where
FR = frequency resolution of the measurement (Hz)
R = timing resolution of the TimerIO() measurement = 540 ns
P = period of input signal (seconds). For example, P = 1 / 1000 Hz = 0.001 s
E = Number of rising edges per scan or 1, whichever is greater.
Table 77. Example. E for a 10 Hz input signal
Scan
Rising Edge / Scan
E
5.0
50
50
0.5
5
5
0.05
0.5
1
TimerIO() instruction measurHVIUHTXHQFLHVRI”N+]ZLWKKLJKHUIUHTXHQF\
resolution over short (sub-second) intervals. In contrast, sub-second frequency
measurement with PulseCount() produce measurements of lower resolution.
Consider a 1 kHz input. Table Frequency Resolution Comparison (p. 354) lists
frequency resolution to be expected for a 1 kHz signal measured by TimerIO()
and PulseCount() at 0.5 s and 5.0 s scan intervals.
Increasing a measurement interval from 1 s to 10 s, either by increasing the scan
interval (when using PulseCount()) or by averaging (when using PulseCount()
or TimerIO()), improves the resulting frequency resolution from 1 Hz to 0.1 Hz.
Averaging can be accomplished by the Average(), AvgRun(), and AvgSpa()
instructions. Also, PulseCount() has the option of entering a number greater than
1 in the POption parameter. Doing so enters an averaging interval in milliseconds
for a direct running-average computation. However, use caution when averaging.
Averaging of any measurement reduces the certainty that the result truly
represents a real aspect of the phenomenon being measured.
Table 78. Frequency Resolution Comparison
PulseCount(), POption=1
TimerIO(), Function=2
0.5 s Scan
5.0 s Scan
FR = 2 Hz
FR = 0.2 Hz
FR = 0.0011 Hz
FR = 0.00011 Hz
8.1.3.3.2 Frequency Measurement Q & A
Q: When more than one pulse is in a scan interval, what does TimerIO() return
when configured for a frequency measurement? Does it average the measured
periods and compute the frequency from that (f = 1/T)? For example,
Scan(50,mSec,10,0)
TimerIO(WindSpd(),11111111,00022000,60,Sec)
354
Section 8. Operation
A: In the background, a 32-bit-timer counter is saved each time the signal
transitions as programmed (rising or falling). This counter is running at a fixed
high frequency. A count is also incremented for each transition. When the
TimerIO() instruction executes, it uses the difference of time between the edge
prior to the last execution and the edge prior to this execution as the time
difference. The number of transitions that occur between these two times divided
by the time difference gives the calculated frequency. For multiple edges
occurring between execution intervals, this calculation does assume that the
frequency is not varying over the execution interval. The calculation returns the
average regardless of how the signal is changing.
8.1.3.4 Switch-Closure and Open-Collector Measurements
Switch-closure and open-collector signals can be measured on P or C terminals.
Mechanical-switch closures have a tendency to bounce before solidly closing.
Unless filtered, bounces can cause multiple counts per event. The CR1000
automatically filters bounce. Because of the filtering, the maximum switchclosure frequency is less than the maximum high-frequency measurement
frequency. Sensors that commonly output a switch-closure or open-collector
signal include:
x
x
x
Tipping-bucket rain gages
Switch-closure anemometers
Flow meters
Data output options include counts, frequency (Hz), and running average.
P Terminals
An internal 100 k: pull-up resistor pulls an input to 5 Vdc with the switch open,
whereas a switch closure to ground pulls the input to 0 V. An internal hardware
debounce filter has a 3.3 ms time-constant. Connection configurations are
illustrated in table Switch Closures and Open Collectors on P Terminals (p. 356).
x
x
Maximum input frequency = 90 Hz
CRBasic instruction: PulseCount()
C Terminals
Switch-closure mode is a special case edge-count function that measures drycontact-switch closures or open collectors. The operating system filters bounces.
Connection configurations are illustrated in table Switch Closures and Open
Collectors on C Terminals (p. 357).
x
x
Maximum input frequency = 150 Hz
CRBasic instruction: PulseCount()
8.1.3.5 Edge Timing
Edge time and period can be measured on P or C terminals. Applications for edge
timing include:
x
Measurements for feedback control using pulse-width or pulse-duration
modulation (PWM/PDM).
Measurements include time between edges expressed as frequency (Hz) or period
(μs).
355
Section 8. Operation
C Terminals
x
x
x
Maximum input frequency <1 kHz
CRBasic instruction: TimerIO()
Rising or falling edges of a square-wave signal are detected:
o
o
x
Rising edge — transition from <1.5 Vdc to >3.5 Vdc.
Falling edge — transition from >3.5 Vdc to <1.5 Vdc.
Edge-timing resolution is approximately 540 ns.
8.1.3.6 Edge Counting
Edge counts can be measured on C terminals.
o
C Terminals
x
x
x
Maximum input frequency 400 kHz
CRBasic instruction: TimerIO()
Rising or falling edges of a square-wave signal are detected:
o
o
Rising edge — transition from <1.5 Vdc to >3.5 Vdc.
Falling edge — transition from >3.5 Vdc to <1.5 Vdc.
8.1.3.7 Pulse Measurement Tips
Basic connection of pulse-output sensors is illustrated in table Switch Closures
and Open Collectors (p. 356, p. 357)
The PulseCount() instruction, whether measuring pulse inputs on P or C
terminals, uses dedicated 24-bit counters to accumulate all counts over the
programmed scan interval. The resolution of pulse counters is one count or 1 Hz.
Counters are read at the beginning of each scan and then cleared. Counters will
overflow if accumulated counts exceed 16,777,216, resulting in erroneous
measurements.
x
x
x
x
356
Counts are the preferred PulseCount() output option when measuring the
number of tips from a tipping-bucket rain gage or the number of times a door
opens. Many pulse-output sensors, such as anemometers and flow meters,
are calibrated in terms of frequency (Hz (p. 517) ) so are usually measured using
the PulseCount() frequency-output option.
Accuracy of PulseCount() is limited by a small scan-interval error of ±(3
ppm of scan interval + 10 μs), plus the measurement resolution error of ±1 /
(scan interval). The sum is essentially ±1 / (scan interval).
Use the LLAC4 (p. 646) module to convert non-TTL-level signals, including
low-level ac signals, to TTL levels for input into C terminals.
As shown in the table Switch Closures and Open Collectors on C Terminals
(p. 357), C terminals, with regard to the 6.2 V Zener diode, have an input
UHVLVWDQFHRINȍZLWKLQSXWYROWDJHV9GF)RULQSXWYROWDJHV•
Vdc, C WHUPLQDOVKDYHDQLQSXWUHVLVWDQFHRIRQO\ȍ
Section 8. Operation
Table 79. Switch Closures and Open Collectors on P Terminals
Switch Closure on P Terminal
Open Collector on on P Terminal
Table 80. Switch Closures and Open Collectors on C Terminals
Switch Closure on C Terminal:
No Pull-Up
Switch Closure on C Terminal:
5 Vdc Pull-Up
Open Collector on C Terminal:
5 Vdc Pull-Up
357
Section 8. Operation
Switch Closure on C Terminal:
12 Vdc Pull-Up
Open Collector on C Terminal:
12 Vdc pull-up
Internal CR1000 circuitry that supports open-collector
and switch-closure measurements (FYI)
x
Pay attention to specifications. Take time to understand the signal to be
measured and compatible input terminals and CRBasic instructions. The
table Three Differing Specifications Between P and C Terminals (p. 358)
compares specifications for pulse-input terminals to emphasize the need for
matching the proper device to the application.
Table 81. Three Specifications Differing Between P and C Terminals
358
P Terminal
C Terminal
High-Frequency
Maximum
250 kHz
400 kHz
Input Voltage
Maximum
20 Vdc
16 Vdc
State Transition
Thresholds
Count upon transition from
<0.9 Vdc to >2.2 Vdc
Count upon transition from
<1.2 Vdc to >3.8 Vdc
Section 8. Operation
8.1.3.7.1 TimerIO() NAN Conditions
x
NAN will be the result of a TimerIO() measurement if one of two conditions
occurs:
o
o
Timeout expires
The signal frequency is too fast (> 3 KHz). When a C terminal
experiences a too fast frequency, the CR1000 operating system disables
the interrupt that is capturing the precise time until the next scan is
serviced. This is done so that the CR1000 processor does not get
occupied by excessive interrupts. A small RC filter retrofitted to the
sensor switch should fix the problem.
8.1.3.7.2 Input Filters and Signal Attenuation
P and C terminals are equipped with pulse-input filters to reduce electronic noise
WKDWFDQFDXVHIDOVHFRXQWV7KHKLJKHUWKHWLPHFRQVWDQWIJRIWKHILOWHUWKH
tighter the filter. The table Time Constants (p. 359) OLVWVIJYDOXHV6RZKLOHDC
terminal measured with the TimerIO() frequency measurement may be superior
for clean signals, a P WHUPLQDOILOWHUPXFKKLJKHUIJPD\EHUHTXLUHGWRJHWD
measurement on an electronically noisy signal.
Input filters attenuate the amplitude (voltage) of the signal. The amount of
attenuation is a function of the frequency passing through the filter. Higherfrequency signals are attenuated more. If a signal is attenuated enough, it may not
pass the state transition thresholds required by the detection device as listed in
table Pulse-Input Terminals and Measurements (p. 69) ). To avoid over attenuation,
sensor-output voltage must be increased at higher frequencies. For example, table
Low-Level Ac Filter Attenuation (p. 360) shows that increasing voltage is required
for low-level ac inputs to overcome filter attenuation on P terminals configured
for low-level ac: 8.5 ms time constant filter (19 Hz 3 dB frequency) for lowamplitude signals; 1 ms time constant (159 Hz 3 dB frequency) for larger (> 0.7
V) amplitude signals.
For P terminals, an RC input filter with an approximate 1 Ps time constant
precedes the inverting CMOS input buffer. The resulting amplitude reduction is
illustrated in figure Amplitude Reduction of Pulse-Count Waveform (p. 360). For a 0
to 5 Vdc square wave input to a pulse terminal, the maximum frequency that can
be counted in high-frequency mode is approximately 250 kHz.
Table 82. 7LPH&RQVWDQWVIJ
Measurement
P terminal low-level ac mode
See footnote of the table Filter Attenuation of
Frequency Signals (p. 360)
P terminal high-frequency mode
1.2
P terminal switch-closure mode
3300
C terminal high-frequency mode
0.025
C terminal switch-closure mode
0.025
359
Section 8. Operation
Table 83. Low-Level Ac Amplitude and Maximum Measured
Frequency
Ac mV (RMS)
20
200
2000
5000
Maximum Frequency
20
200
10,000
20,000
Figure 94. Amplitude reduction of pulse-count waveform (before and after
1 μs time-constant filter)
8.1.4
Period Averaging — Details
Related Topics:
‡3HULRG$YHUDJLQJ— Specifications
‡Period Averaging — Overview (p. 70)
‡Period Averaging — Details (p. 360)
The CR1000 can measure the period of a signal on a SE terminal. The specified
number of cycles is timed with a resolution of 136 ns, making the resolution of
the period measurement 136 ns ns divided by the number of cycles chosen.
Low-level signals are amplified prior to a voltage comparator. The internal
voltage comparator is referenced to the programmed threshold. The threshold
parameter allows referencing the internal voltage comparator to voltages other
than 0 V. For example, a threshold of 2500 mV allows a 0 to 5 Vdc digital signal
to be sensed by the internal comparator without the need of any additional input
conditioning circuitry. The threshold allows direct connection of standard digital
360
Section 8. Operation
signals, but it is not recommended for small amplitude sensor signals. For sensor
amplitudes less than 20 mV peak-to-peak, a dc blocking capacitor is
recommended to center the signal at CR1000 ground (threshold = 0) because of
offset voltage drift along with limited accuracy (r10 mV) and resolution (1.2 mV)
of a threshold other than zero. Figure Input Conditioning Circuit for Period
Averaging (p. 361) shows an example circuit.
The minimum pulse-width requirements increase (maximum frequency decreases)
with increasing gain. Signals larger than the specified maximum for a range will
saturate the gain stages and prevent operation up to the maximum specified
frequency. As shown, back-to-back diodes are recommended to limit large
amplitude signals to within the input signal ranges.
Caution Noisy signals with slow transitions through the voltage threshold have
the potential for extra counts around the comparator switch point. A voltage
comparator with 20 mV of hysteresis follows the voltage gain stages. The
effective input-referred hysteresis equals 20 mV divided by the selected voltage
gain. The effective input referred hysteresis on the r 25 mV range is 2 mV;
consequently, 2 mV of noise on the input signal could cause extraneous counts.
For best results, select the largest input range (smallest gain) that meets the
minimum input signal requirements.
Figure 95. Input Conditioning Circuit for Period Averaging
8.1.5
Vibrating-Wire Measurements — Details
Related Topics:
‡9LEUDWLQJ-Wire Measurements — Specifications
‡Vibrating-Wire Measurements — Overview (p. 71)
‡Vibrating-Wire Measurements — Details (p. 361)
The CR1000 can measure vibrating-wire or vibrating-strip sensors, including
strain gages, pressure transducers, piezometers, tilt meters, crack meters, and load
cells. These sensors are used in structural, hydrological, and geotechnical
applications because of their stability, accuracy, and durability. The CR1000 can
measure vibrating-wire sensors through specialized interface modules. More
sensors can be measured by using multiplexers (see Analog Multiplexers (p. 646) ).
361
Section 8. Operation
The figure Vibrating-Wire Sensor (p. 362) illustrates basic construction of a sensor.
To make a measurement, plucking and pickup coils are excited with a swept
frequency (p. 530). The ideal behavior then is that all non-resonant frequencies
quickly decay, and the resonant frequency continues. As the resonant frequency
cuts the lines of flux in the pickup coil, the same frequency is induced on the
signal wires in the cable connecting the sensor to the CR1000 or interface.
Measuring the resonant frequency by means of period averaging is the classic
technique, but Campbell Scientific has developed static and dynamic spectralanalysis techniques (VSPECT (p. 532)tm) that produce superior noise rejection,
higher resolution, diagnostic data, and, in the case of dynamic VSPECT,
measurements up to 333.3 Hz.
A resistive-thermometer device (thermistor or RTD), which is included in most
vibrating-wire sensor housings, can be measured to compensate for temperature
errors in the measurement.
Figure 96. Vibrating-Wire Sensor
8.1.5.1 Time-Domain Measurement
Although obsolete in many applications, time-domain period-averaging vibratingwire measurements can be made on H L terminals. The VibratingWire()
instruction makes the measurement. Measurements can be made directly on these
terminals, but usually are made through a vibrating-wire interface that amplifies
and conditions the vibrating-wire signal and provides inputs for embedded
thermistors or RTDs. Interfaces of this type are no longer available from
Campbell Scientific.
For most applications, the advanced techniques of static and dynamic VSPECTTM
measurements are preferred.
8.1.6
Reading Smart Sensors — Details
Related Topics:
‡Reading Smart Sensors — Overview (p. 71)
‡Reading Smart Sensors — Details (p. 362)
8.1.6.1 RS-232 and TTL
Read More Serial Input / Output Instructions (p. 583) and Serial I/O (p. 245).
The CR1000 can receive and record most TTL (0 to 5 Vdc) and true RS-232 data
from devices such as smart sensors. See the table CR1000 Terminal Definitions (p.
362
Section 8. Operation
76) for those terminals and serial ports configurable for either TTL or true RS-232
communications. Use of the CS I/O port for true RS-232 communications
requires use of an interface device. See the appendix CS I/O Serial Interfaces (p.
652). If additional serial inputs are required, serial input expansion modules can be
connected. See the appendix Serial I/O Modules List (p. 646). Serial data are
usually captured as text strings, which are then parsed (split up) as defined in the
CRBasic program.
Note C terminals configured as Tx transmit only 0 to 5 Vdc logic. However, C
terminals configured as Rx read most true RS-232 signals. When connecting
serial sensors to a C terminal configured as Rx, the sensor power consumption
may increase by a few milliamps due to voltage clamps in the CR1000. An
external resistor may need to be added in series to the Rx line to limit the current
drain, although this is not advisable at very high baud rates. Figure Circuit to
Limit C Terminal RS-232 Input to 5 Volts (p. 363) shows a circuit that limits
voltage to 5 Vdc.
Figure 97. Circuit to Limit C Terminal Input to 5 Vdc
8.1.6.2 SDI-12 Sensor Support — Details
Related Topics:
‡SDI-12 Sensor Support — Overview (p. 72)
‡SDI-12 Sensor Support — Details (p. 363)
‡Serial I/O: SDI-12 Sensor Support — Programming Resource (p. 267)
‡SDI-12 Sensor Support — Instructions (p. 555)
SDI-12 is a communication protocol developed to transmit digital data from smart
sensors to data-acquisition units. It is a simple protocol, requiring only a single
communication wire. Typically, the data-acquisition unit also supplies power (12
Vdc and ground) to the SDI-12 sensor. SDI12Recorder() instruction
communicates with SDI-12 sensors on terminals configured for SDI-12 input.
See the table CR1000 Terminal Definitions (p. 76) to determine those terminals
configurable for SDI-12 communications.
8.1.7
Field Calibration — Overview
Related Topics:
‡Field Calibration — Overview (p. 73)
‡Field Calibration — Details (p. 210)
Calibration increases accuracy of a measurement device by adjusting its output, or
the measurement of its output, to match independently verified quantities.
Adjusting sensor output directly is preferred, but not always possible or practical.
363
Section 8. Operation
By adding FieldCal() or FieldCalStrain() instructions to the CR1000 CRBasic
program, measurements of a linear sensor can be adjusted by modifying the
programmed multiplier and offset applied to the measurement.
8.1.8
Cabling Effects
Related Topics:
‡Cabling Effects — Overview (p. 74)
‡Cabling Effects — Details (p. 364)
Sensor cabling can have significant effects on sensor response and accuracy. This
is usually only a concern with sensors acquired from manufacturers other than
Campbell Scientific. Campbell Scientific sensors are engineered for optimal
performance with factory-installed cables.
8.1.8.1 Analog-Sensor Cables
Cable length in analog sensors is most likely to affect the signal settling time. For
more information, see the section Signal Settling Time (p. 317).
8.1.8.2 Pulse Sensors
Because of the long interval between switch closures in tipping-bucket rain gages,
appreciable capacitance can build up between wires in long cables. A built-up
charge can cause arcing when the switch closes and so shorten switch life. As
shown in figure Current Limiting Resistor in a Rain Gage Circuit (p. 364), Dȍ
resistor is connected in series at the switch to prevent arcing. This resistor is
installed on all rain gages currently sold by Campbell Scientific.
Figure 98. Current-Limiting Resistor in a Rain Gage Circuit
8.1.8.3 RS-232 Sensors
RS-232 sensor cable lengths should be limited to 50 feet.
8.1.8.4 SDI-12 Sensors
The SDI-12 standard allows cable lengths of up to 200 feet. Campbell Scientific
does not recommend SDI-12 sensor lead lengths greater than 200 feet; however,
longer lead lengths can sometimes be accommodated by increasing the wire gage
or powering the sensor with a second 12 Vdc power supply placed near the
sensor.
364
Section 8. Operation
8.1.9
Synchronizing Measurements
Related Topics:
‡Synchronizing Measurements — Overview (p. 74)
‡Synchronizing Measurements — Details (p. 365)
Timing of a measurement is usually controlled relative to the CR1000 clock.
When sensors in a sensor network are measured by a single CR1000,
measurement times are synchronized, often within a few milliseconds, depending
on sensor number and measurement type. Large numbers of sensors, cable length
restrictions, or long distances between measurement sites may require use of
multiple CR1000s. Techniques outlined below enable network administrators to
synchronize CR1000 clocks and measurements in a CR1000 network.
Care should be taken when a clock-change operation is planned. Any time the
CR1000 clock is changed, the deviation of the new time from the old time may be
sufficient to cause a skipped record in data tables. Any command used to
synchronize clocks should be executed after any CallTable() instructions and
timed so as to execute well clear of data-output intervals.
Techniques to synchronize measurements across a network include:
1. LoggerNet (p. 95) – when reliable telecommunications are common to all
CR1000s in a network, the LoggerNet automated clock check provides a
simple time synchronization function. Accuracy is limited by the system
clock on the PC running the LoggerNet server. Precision is limited by
network transmission latencies. LoggerNet compensates for latencies in many
telecommunication systems and can achieve synchronies of <100 ms
deviation. Errors of 2 to 3 second may be seen on very busy RF connections
or long distance internet connections.
Note Common PC clocks are notoriously inaccurate. Information available at
http://www.nist.gov/pml/div688/grp40/its.cfm gives some good pointers on
keeping PC clocks accurate.
2. Digital trigger — a digital trigger, rather than a clock, can provide the
synchronization signal. When cabling can be run from CR1000 to CR1000,
each CR1000 can catch the rising edge of a digital pulse from the master
CR1000 and synchronize measurements or other functions, using the
WaitDigTrig() instructions, independent of CR1000 clocks or data time
stamps. When programs are running in pipeline mode, measurements can be
synchronized to within a few microseconds (see WaitDigTrig Scans (p. 157) ).
3. PakBus (p. 88) commands — the CR1000 is a PakBus device, so it is capable of
being a node in a PakBus network. Node clocks in a PakBus network are
synchronized using the SendGetVariable(), ClockReport(), or
PakBusClock() commands. The CR1000 clock has a resolution of 10 ms,
which is the resolution used by PakBus clock-sync functions. In networks
without routers, repeaters, or retries, the communication time will cause an
additional error (typically a few 10s of milliseconds). PakBus clock
commands set the time at the end of a scan to minimize the chance of skipping
a record to a data table. This is not the same clock check process used by
LoggerNet as it does not use average round trip calculations to try to account
for network connection latency.
365
Section 8. Operation
4. Radios — A PakBus enabled radio network has an advantage over Ethernet in
that ClockReport() can be broadcast to all dataloggers in the network
simultaneously. Each will set its clock with a single PakBus broadcast from
the master. Each datalogger in the network must be programmed with a
PakBusClock() instruction.
Note Use of PakBus clock functions re-synchronizes the Scan() instruction. Use
should not exceed once per minute. CR1000 clocks drift at a slow enough rate
that a ClockReport() once per minute should be sufficient to keep clocks within
30 ms of each other.
With any synchronization method, care should be taken as to when and how
things are executed. Nudging the clock can cause skipped scans or skipped
records if the change is made at the wrong time or changed by too much.
5. GPS — clocks in CR1000s can be synchronized to within about 10 ms of each
other using the GPS() instruction. CR1000s built since October of 2008
VHULDOQXPEHUV•>@FDQEHV\QFKURQL]HGZLWKLQDIHZPLFURVHFRQGV
RIHDFKRWKHUDQGZLWKLQ§—VRI87&:KLOHD*36VLJQDOLVDYDLODble,
the CR1000 essentially uses the GPS as its continuous clock source, so the
chances of jumps in system time and skipped records are minimized.
6. Ethernet — any CR1000 with a network connection (internet, GPRS, private
network) can synchronize its clock relative to Coordinated Universal Time
(UTC) using the NetworkTimeProtocol() instruction. Precisions are usually
maintained to within 10 ms. The NTP server could be another logger or any
NTP server (such as an email server or nist.gov). Try to use a local server —
something where communication latency is low, or, at least, consistent. Also,
try not to execute the NetworkTimeProtocol() at the top of a scan; try to ask
for the server time between even seconds.
8.2
Measurement and Control Peripherals — Details
Related Topics:
‡Measurement and Control Peripherals — Overview (p. 85)
‡Measurement and Control Peripherals — Details (p. 366)
‡Measurement and Control Peripherals — Lists (p. 645)
Peripheral devices expand the CR1000 input and output capacities. Some
peripherals are designed as SDM (synchronous devices for measurement) or
CDM (CPI devices for measurement). SDM and CDM devices are intelligent
peripherals that receive instruction from, and send data to, the CR1000 using
proprietary communication protocols through SDM terminals and CPI interfaces.
The following sections discuss peripherals according to measurement types.
8.2.1
Analog-Input Modules
Read More For more information see appendix Analog-Input Modules List (p. 646).
Mechanical and solid-state multiplexers are available to expand the number of
analog sensor inputs. Multiplexers are designed for single-ended, differential,
bridge-resistance, or thermocouple inputs.
366
Section 8. Operation
8.2.2
Pulse-Input Modules
Read More For more information see appendix Pulse-Input Modules List (p. 646).
Pulse-input expansion modules are available for switch-closure, state, pulse-count
and frequency measurements, and interval timing.
8.2.2.1 Low-Level Ac Input Modules — Overview
Related Topics:
‡Low-Level Ac Input Modules — Overview (p. 367)
‡Low-Level Ac Measurements — Details (p. 352)
‡Pulse Input Modules — Lists (p. 646)
Low-level ac input modules increase the number of low-level ac signals a
CR1000 can monitor by converting low-level ac to high-frequency pulse.
8.2.3
Serial I/O Modules — Details
Read More For more information see appendix Serial I/O Modules List (p. 646).
Capturing input from intelligent serial-output devices can be challenging. Several
Campbell Scientific serial I/O modules are designed to facilitate reading and
parsing serial data. Campbell Scientific recommends consulting with an
application engineer when deciding which serial-input module is suited to a
particular application.
8.2.4
Terminal-Input Modules
Read More For more information see appendix Passive Signal Conditioners List
(p. 647).
Terminal Input Modules (TIMs) are devices that provide simple measurementsupport circuits in a convenient package. TIMs include voltage dividers for
cutting the output voltage of sensors to voltage levels compatible with the
CR1000, modules for completion of resistive bridges, and shunt modules for
measurement of analog-current sensors.
8.2.5
Vibrating-Wire Modules
Read More For complete information see appendix Vibrating-Wire Modules List
(p. 647).
Vibrating-wire modules interface vibrating-wire transducers to the CR1000.
8.2.6
Analog-Output Modules
Read More For more information see appendix Continuous-Analog-Output
(CAO) Modules List (p. 649).
The CR1000 can scale measured or processed values and transfer these values in
digital form to an analog output device. The analog output device performs a
367
Section 8. Operation
digital-to-analog conversion to output an analog voltage or current. The output
level is maintained until updated by the CR1000.
8.2.7
PLC Control Modules — Overview
Related Topics:
‡PLC Control — Overview (p. 74)
‡PLC Control — Details (p. 244)
‡PLC Control Modules — Overview (p. 368)
‡PLC Control Modules — Lists (p. 648)
‡PLC Control — Instructions (p. 562)
‡6ZLWFKHG9ROWDJH2XWSXW— Specifications
‡6ZLWFKHG9ROWDJH2XWSXW — Overview
‡Switched Voltage Output — Details (p. 103)
Controlling power to an external device is a common function of the CR1000.
On-board control terminals and peripheral devices are available for binary (on /
off) or analog (variable) control. A switched, 12 Vdc terminal (SW12V) is also
available. See the section Switched Unregulated (Nominal 12 Volt) (p. 105).
8.2.7.1 Terminals Configured for Control
C terminals can be configured as output ports so set low (0 Vdc) or high (5 Vdc)
using the PortSet() or WriteIO() instructions. Ports C4, C5, and C7 can be
configured for pulse width modulation with maximum periods of 36.4 s, 9.1 s, and
2.27 s, respectively. A terminal configured for digital I/O is normally used to
operate an external relay-driver circuit because the port itself has limited drive
capacity. Drive capacity is determined by the 5 Vdc supply and a ȍ output
resistance. It is expressed as:
Vo = 4.9 V – ȍ‡,o
Where Vo is the drive limit, and Io is the current required by the external device.
Figure Control Port Current Sourcing (p. 369) plots the relationship.
368
Section 8. Operation
Figure 99. Current sourcing from C terminals configured for control
8.2.7.2 Relays and Relay Drivers
Read More For more information see appendix Relay Drivers Modules List (p.
649).
Several relay drivers are manufactured by Campbell Scientific. Compatible,
inexpensive, and reliable single-channel relay drivers for a wide range of loads are
also available from electronic vendors such as Crydom, Newark, and Mouser (p.
534).
8.2.7.3 Component-Built Relays
Figure Relay Driver Circuit with Relay (p. 370) shows a typical relay driver circuit
in conjunction with a coil driven relay, which may be used to switch external
power to a device. In this example, when the terminal configured for control is set
high, 12 Vdc from the datalogger passes through the relay coil, closing the relay
which completes the power circuit and turns on the fan.
In other applications, it may be desirable to simply switch power to a device
without going through a relay. Figure Power Switching without Relay (p. 370)
illustrates this. If the device to be powered draws in excess of 75 mA at room
temperature (limit of the 2N2907A medium power transistor), the use of a relay is
required.
369
Section 8. Operation
8.3
Figure 100.
Relay Driver Circuit with Relay
Figure 101.
Power Switching without Relay
Memory
Related Topics:
‡Memory — Overview (p. 87)
‡Memory — Details (p. 370)
‡Data Storage Devices — List (p. 653)
8.3.1
Storage Media
CR1000 memory consists of four non-volatile storage media:
x
x
x
x
x
370
Internal battery-backed SRAM
Internal flash
Internal serial flash
External flash (optional flash USB: drive)
External CompactFlash® optional CF card and module (CRD: drive) (p. 653)
Section 8. Operation
Table CR1000 Memory Allocation (p. 371) and table CR1000 SRAM Memory (p. 372)
illustrate the structure of CR1000 memory around these media. The CR1000 uses
and maintains most memory features automatically. However, users should
periodically review areas of memory wherein data files, CRBasic program files,
and image files reside. See section File Management in CR1000 Memory (p. 382)
for more information.
By default, final-data memory (memory for stored data) is organized as ring
memory. When the ring is full, oldest data are overwritten by newest data. The
DataTable() instruction, however, has an option to set a data table to Fill and
Stop.
Table 84. CR1000 Memory Allocation
Memory
Comments
Sector
Main
1
Battery-Backed SRAM
4 MB*
Operating System
2
Flash Memory
2 MB
x
OS variables
x
CRBASIC compiled program binary structure
x
CRBASIC variables
x
Final-data memory
x
Communication memory
x
USR: FAT32 RAM drive
x
'Keep' memory
x
Dynamic runtime memory allocation
x
See table CR1000 SRAM Memory (p. 372) for detail.
x
Operating system
x
Serial number
x
Board revision
x
Boot code
x
Erased when loading new OS. Boot code erased only if changed.
371
Section 8. Operation
Table 84. CR1000 Memory Allocation
Internal
Serial Flash
3
512 kB
External Flash
(Optional)
2 GB: USB: drive
External CompactFlash
(Optional)
”*%&5'GULYH
1
x
Device settings (12 kB) — PakBus address and settings, station name.
Rebuilt when a setting changes.
x
CPU:drive (500 kB) — program files, field calibration files, other files not
frequently overwritten. When a program is compiled and run, it is copied
here automatically for loading on subsequent power-ups. Files
accumulate until deleted with File Control or the FilesManage()
instruction. Use USR: drive to store other file types. Available CPU:
memory is reported in Status table field CPUDriveFree.
x
FAT32 file system
x
Limited write cycles (100,000)
x
Slow serial access
USB: drive (p. 653) — Holds program files. Holds a copy of requested final-memory
table data as files when TableFile() instruction is used. USB: data can be retrieved
from the storage device with Windows Explorer. USB: drive can facilitate the use of
Powerup.ini.
CRD: drive (p. 653) — Holds program files. Holds a copy of final-storage table data as
files when TableFile() instruction with Option 64 is used (replaces CardOut()). See
Writing High-Frequency Data to Memory Cards (p. 205) for more information. When
data are requested by a PC, data first are provided from SRAM. If the requested records
have been overwritten in SRAM, data are sent from CRD:. Alternatively, CRD: data
can be retrieved in a binary format using datalogger support software (p. 95) File
Control. Binary files are converted using CardConvert software. 10% or 80 kB of CF
memory (whichever is smaller) is reserved for program storage. CF cards can facilitate
the use of Powerup.ini.
SRAM
Â&5FKDQJHGIURPWR0%65$0LQ6HSW61V•DUH0%
2 Flash is rated for > 1 million overwrites.
3
Serial flash is rated for 100,000 overwrites (50,000 overwrites on 128 kB units). Care should be taken in programs that
overwrite memory to use the CRD: or USR: drives so as not to wear-out the CPU: drive.
Â7KH&5FKDQJHGIURPWRN%VHULDOIODVKLQ0D\61V•DUHN%
372
Section 8. Operation
Table 85. CR1000 Main Memory
Use
Static Memory
————————————
Operating Settings and Properties
————————————
CRBasic Program
Operating Memory
————————————
Variables & Constants
————————————
Final-Data Memory
————————————
Communication Memory 1
————————————
Communication Memory 2
————————————
USR: drive
<= 3.6 MB (4 MB Mem)
<= 1.5 MB (2 MB Mem)
Comments
Operational memory used by the operating system. Rebuilt at power-up,
program re-compile, and watchdog events.
"Keep" (p. 519) memory. Stores settings such as PakBus address, station name,
beacon intervals, neighbor lists, etc. Also stores dynamic properties such as the
routing table, communication timeouts, etc.
Stores the currently compiled and running user program. This sector is rebuilt on
power-up, recompile, and watchdog events.
Stores variables used by the CRBasic program. These values may persist
through power-up, recompile, and watchdog events if the PreserveVariables
instruction is in the running program.
Stores data. Fills memory remaining after all other demands are satisfied.
Configurable as ring or fill-and-stop memory. Compile error occurs if
insufficient memory is available for user-allocated data tables. Given lowest
priority in SRAM memory allocation.
Construction and temporary storage of PakBus packets.
Constructed Routing Table: list of known nodes and routes to nodes. Routers use
more space than leaf nodes because routes to neighbors must be remembered.
Increasing the PakBusNodes field in the Status table will increase this allocation.
Optionally allocated. Holds image files. Holds a copy of final-data memory
when TableFile() instruction used. Provides memory for FileRead() and
FileWrite() operations. Managed in File Control. Status reported in Status
table fields "USRDriveSize" and "USRDriveFree."
Less on older units with more
limited memory.
373
Section 8. Operation
Table 86. Memory Drives
Drive
CPU:
USR:
Recommended File Types
1
cr1, .CAL
2
cr1, .CAL
USB:
.DAT
CRD:
Principal use is to expand final-data memory
(p. 515), but it is also used to store .JPG, cr1,
and .DAT files.
1
The CPU: drive uses a FAT16 file system, so it is limited to 128 file. If the file names are longer
than 8.3 characters (e.g. 12345678.123), you can store less.
2
The USR: drive uses a FAT32 file system, so there is no limit, beyond practicality and available
memory, to the number of files that can be stored. While a FAT file system is subject to
fragmentation, performance degradation is not likely to be noticed since the drive has very fast
access because it has a relatively small amount of solid state RAM.
3
The CRD: drive is a CompactFlash card attached to the CR1000 by use of a CF card storage
module (p. 653). Cards should be formatted as FAT32 for optimal performance. The card format
feature in the CR1000 will format the card with the same format previously used on the card.
8.3.1.1 Memory Drives — On-Board
Data-storage drives are listed in table CR1000 Memory Drives (p. 373). Data-table
SRAM and the CPU: drive are automatically partitioned for use in the CR1000.
The USR: drive can be partitioned as needed. The USB: drive is automatically
partitioned when a Campbell Scientific mass-storage device (p. 653) is connected.
The CRD: drive is automatically partitioned when a memory card is installed.
8.3.1.1.1 Data Table SRAM
Primary storage for measurement data are those areas in SRAM allocated to data
tables as detailed in table CR1000 SRAM Memory (p. 372). Measurement data can
be also be stored as discrete files on USR: or USB: by using TableFile()
instruction.
The CR1000 can be programmed to store each measurement or, more commonly,
to store processed values such as averages, maxima, minima, histograms, FFTs,
etc. Data are stored periodically or conditionally in data tables in SRAM as
directed by the CRBasic program (see Structure (p. 123) ). The DataTable()
instruction allows the size of a data table to be programmed. Discrete data files
are normally created only on a PC when data are retrieved using datalogger
support software (p. 95).
Data are usually erased from this area when a program is sent to the CR1000.
However, when using support software File Control menu Send (p. 515) command
or CRBasic Editor Compile, Save and Send (p. 511) command, options are
available to preserve data when downloading programs.
8.3.1.1.2 CPU: Drive
CPU: is the default drive on which programs and calibration files are stored. It is
formatted as FAT16, so it has a limit of 128 files. Do not store data on CPU: or
premature failure of memory will likely result.
374
Section 8. Operation
8.3.1.1.3 USR: Drive
SRAM can be partitioned to create a FAT32 USR: drive, analogous to partitioning
a second drive on a PC hard disk. Certain types of files are stored to USR: to
reserve limited CPU: memory for datalogger programs and calibration files.
Partitioning also helps prevent interference from data table SRAM. USR: is
configured using DevConfig settings or SetStatus() instruction in a CRBasic
program. Partition USR: drive to at least 11264 bytes in 512-byte increments. If
the value entered is not a multiple of 512 bytes, the size is rounded up. Maximum
size of USR: is the total RAM size less 400 kB; i.e., for a CR1000 with 4 MB
memory, the maximum size of USR: is about 3.6 MB.
USR: is not affected by program recompilation or formatting of other drives. It
will only be reset if the USR: drive is formatted, a new operating system is
loaded, or the size of USR: is changed. USR: size is changed manually by
accessing it in the Status table or by loading a CRBasic program with a different
USR: drive size entered in a SetStatus() or SetSetting() instruction. See section
Configuration with CRBasic Program (p. 115).
Measurement data can be stored on USR: as discrete files by using the
TableFile() instruction. Table TableFile()-Instruction Data-File Formats (p. 378)
describes available data-file formats.
Note Placing an optional USR: size setting in the CRBasic program over-rides
manual changes to USR: size. When USR: size is changed manually, the
CRBasic program restarts and the programmed size for USR: takes immediate
effect.
The USR: drive holds any file type within the constraints of the size of the drive
and the limitations on filenames. Files typically stored include image files from
cameras (see the appendix Cameras ), certain configuration files, files written for
FTP retrieval, HTML files for viewing with web access, and files created with the
TableFile() instruction. Files on USR: can be collected using datalogger support
software (p. 95) Retrieve (p. 515) command, or automatically using the datalogger
support software Setup File Retrieval tab functions.
Monitor use of available USR: memory to ensure adequate space to store new
files. FileManage() command can be used in the CRBasic program to remove
files. Files also can be removed using datalogger support software Delete (p. 515)
command.
Two Status table registers monitor use and size of the USR: drive. Bytes
remaining are indicated in register USRDriveFree. Total size is indicated in
register USRDriveSize. Memory allocated to USR: drive, less overhead for
directory use, is shown in datalogger support software File Control (p. 515)
window.
8.3.1.1.4 USB: Drive
USB: drive uses Flash (p. 516) memory on a Campbell Scientific mass storage
device (see the appendix Mass Storage Devices (p. 653) ). Its primary purpose is the
storage of ASCII data files. Measurement data can be stored on USB: as discrete
files by using the TableFile() instruction. Table TableFile()-Instruction Data-File Formats (p.
378)Term. Flash (p. 516)describes available data-file formats.
375
Section 8. Operation
Caution When removing mass-storage devices, do so when the LED is not
flashing or lit.
Consider the following when using Campbell Scientific mass-storage devices:
x
x
x
format as FAT32
connect to the CR1000 CS I/O port
remove only when inactive or data corruption may result
8.3.1.2 Memory Card (CRD: Drive) — Details
Related Topics:
‡Memory Card (CRD: Drive) — Overview (p. 89)
‡Memory Card (CRD: Drive) — Details (p. 376)
‡Memory Cards and Record Numbers (p. 466)
‡Data Output: Writing High-Frequency Data to Memory Cards (p. 205)
‡File-System Errors (p. 389)
‡Data Storage Devices — List (p. 653)
‡Data-File Format Examples (p. 379)
‡Data Storage Drives Table (p. 373)
The CRD: drive uses CompactFlash® (CF) card memory cards exclusively. Its
primary purpose is the storage of binary data files. The CR1000 requires addition
of a peripheral card slot. See appendix Data Storage Devices List (p. 653).
Purchasing industrial grade memory cards from Campbell Scientific is
recommended. Use of consumer grade cards substantially increases the risk of
data loss.
Caution Use care when inserting or removing memory cards. Alway turn off
CR1000 power before installing or removing card modules. Removing a card
from the module while it is being written to can cause data corruption or damage
the card. Before removing the card, press the removal or eject button and wait for
the LED to indicate that the card is disabled.
To prevent losing data, collect data from the memory card before sending a
program to the datalogger. When a program is sent to the datalogger all data on
the memory card may be erased.
Campbell Scientific CF card modules connect to the CR1000 peripheral port.
Each has a slot for Type I or Type II CF cards .A maximum of 30 data tables can
be created on a memory card.
Note CardConvert software, included with mid- and top-level datalogger support
software (p. 654), converts binary card data to the standard Campbell Scientific data
format.
When a data table is sent to a memory card, a data table of the same name in
SRAM is used as a buffer for transferring data to the card. When the card is
present, the Status table will show the size of the table on the card. If the card is
removed, the size of the table in SRAM is shown.
When a new program is compiled that sends data to the memory card, the CR1000
checks if a card is present and if the card has adequate space for the data tables. If
no card is present, or if space is inadequate, the CR1000 will warn that the card is
not being used. However, the CRBasic program runs anyway and data are stored
376
Section 8. Operation
to SRAM. When a card is inserted later, data accumulated in the SRAM table are
copied to the card.
Formatting Memory Cards
The CR1000 accepts memory cards formatted as FAT or FAT32; however,
FAT32 is recommended. Otherwise, some functionality, such as the ability to
manage large numbers of files (>254) is lost. Older CR1000 operating systems
formatted cards as FAT or FAT32. Newer operating systems always format cards
as FAT32.
To avoid long compile times on a freshly formatted card, format the card on a PC,
then copy a small file to the card, and then delete the file (while still in the PC).
Copying the file to the freshly formatted card forces the PC to update the info
sector. The PC is much faster than the datalogger at updating the info sector.
FAT32 uses an “info sector” to store the free cluster information. This info sector
prevents the need to repeatedly traverse the FAT for the bytes free information.
After a card is formatted by a PC, the info sector is not automatically updated.
Therefore, when the datalogger boots up, it must determine the bytes available on
the card prior to loading the Status table. Traversing the entire FAT of a 16 GB
card can take up to 30 minutes or more. However, subsequent compile times are
much shorter because the info sector is used to update the bytes free information.
Table 87. Memory Card States
CardStatus
CardBytesFr
ee
Card OK
>0
CompileResult
s
No Card
Present.
Card Not
Being Used
Initializing
Table Files!
8.3.2
Situation(s)
Formatted card inserted, powered up
>0
No Card
Present
LED
Solid green for 20 s
Card still inserted, but removal button has been pressed
-1
CFM100/NL115 removed while logger is running (do not do
this)
>0
Program contains CardOut(). Card inserted before power up.
-1
Powered up, no card present
-1
Card ejected / physically removed
-1
Logger started without CFM100 / NL115
-1
Compact Flash
Module not
detected: CardOut
not used.
Program contains CardOut(). CFM100/NL115 not attached at
power up.
-1
Solid Orange
Program contains CardOut(). Card not present at power up.
0, have also seen
with -1, that
doesn't seem
consistent
Dim / fast flashing
Orange
Program contains CardOut(). Card not present at power up. Card
inserted after power up. If all goes well, CardStatus will change
to "Card OK." and CardBytesFree will be >0.
Data-File Formats
Data-file format options are available with the TableFile() instruction. Timeseries data have an option to include header, time stamp and record number. See
the table TableFile() Instruction Data-File Formats (p. 378). For a format to be
compatible with datalogger support software (p. 95) graphing and reporting tools,
377
Section 8. Operation
header, time stamps, and record numbers are usually required. Fully compatible
formats are indicated with an asterisk. A more detailed discussion of data-file
formats is available in the Campbell Scientific publication LoggerNet Instruction
Manual, which is available at www.campbellsci.com.
Table 88. TableFile() Instruction Data-File Formats
Elements Included
TableFile()
Format
Option
Base
File
Format
1
Header
Information
Time
Stamp
Record
Number
TOB1
9
9
9
1
TOB1
9
9
2
TOB1
9
3
TOB1
9
4
TOB1
9
5
TOB1
9
6
TOB1
7
TOB1
1
TOA5
9
9
9
TOA5
9
9
10
TOA5
9
11
TOA5
9
12
TOA5
9
13
TOA5
9
14
TOA5
15
TOA5
0
8
9
17
CSIXML
9
9
18
CSIXML
9
19
CSIXML
9
1
CSIJSON
9
9
33
CSIJSON
9
9
34
CSIJSON
9
35
CSIJSON
9
64
2
9
9
9
2
9
9
CSIXML
32
9
9
1
16
1
9
9
9
9
9
TOB3
Formats compatible with datalogger support software (p. 95) data-viewing and graphing utilities
See Writing High-Frequency Data to Memory Cards (p. 205) for more information on using
option 64.
378
Section 8. Operation
Data-File Format Examples
TOB1
TOB1 files may contain an ASCII header and binary data. The last line in the
example contains cryptic text which represents binary data.
Example:
"TOB1","11467","CR1000","11467","CR1000.Std.20","CPU:file format.CR1","61449","Test"
"SECONDS","NANOSECONDS","RECORD","battfivoltfiMin","PTemp"
"SECONDS","NANOSECONDS","RN","",""
"","","","Min","Smp"
"ULONG","ULONG","ULONG","FP2","FP2"
}Ÿp'
E1HŒŸp'
E1H›Ÿp'
E1HªŸp'
E1H¹Ÿp'
E1H
TOA5
TOA5 files contain ASCII (p. 507) header and comma-separated data.
Example:
"TOA5","11467","CR1000","11467","CR1000.Std.20","CPU:file format.CR1","26243","Test"
"TIMESTAMP","RECORD","battfivoltfiMin","PTemp"
"TS","RN","",""
"","","Min","Smp"
"2010-12-20 11:31:30",7,13.29,20.77
"2010-12-20 11:31:45",8,13.26,20.77
"2010-12-20 11:32:00",9,13.29,20.8
CSIXML
CSIXML files contain header information and data in an XML (p. 533) format.
Example:
<?xml version="1.0" standalone="yes"?>
<csixml version="1.0">
<head>
<environment>
<station-name>11467</station-name>
<table-name>Test</table-name>
<model>CR1000</model>
<serial-no>11467</serial-no>
<os-version>CR1000.Std.20</os-version>
<dld-name>CPU:file format.CR1</dld-name>
</environment>
<fields>
<field name="battfivoltfiMin" type="xsd:float" process="Min"/>
<field name="PTemp" type="xsd:float" process="Smp"/>
</fields>
</head>
<data>
<r time="2010-12-20T11:37:45" no="10"><v1>13.29</v1><v2>21.04</v2></r>
<r time="2010-12-20T11:38:00" no="11"><v1>13.29</v1><v2>21.04</v2></r>
<r time="2010-12-20T11:38:15" no="12"><v1>13.29</v1><v2>21.04</v2></r>
</data>
</csixml>
379
Section 8. Operation
CSIJSON
CSIJSON files contain header information and data in a JSON (p. 519) format.
Example:
"signature": 38611,"environment": {"stationfiname": "11467","tablefiname":
"Test","model": "CR1000","serialfino": "11467",
"osfiversion": "CR1000.Std.21.03","progfiname": "CPU:file format.CR1"},"fields":
[{"name": "battfivoltfiMin","type": "xsd:float",
"process": "Min"},{"name": "PTemp","type": "xsd:float","process": "Smp"}]},
"data": [{"time": "2011-01-06T15:04:15","no": 0,"vals": [13.28,21.29]},
{"time": "2011-01-06T15:04:30","no": 1,"vals": [13.28,21.29]},
{"time": "2011-01-06T15:04:45","no": 2,"vals": [13.28,21.29]},
{"time": "2011-01-06T15:05:00","no": 3,"vals": [13.28,21.29]}]}
Data File-Format Elements
Header
File headers provide metadata that describe the data in the file. A TOA5
header contains the metadata described below. Other data formats contain
similar information unless a non-header format option is selected in the
TableFile() instruction in the CR1000 CRBasic program.
Line 1 – Data Origins
Includes the following metadata series: file type, station name, CR1000
model name, CR1000 serial number, OS version, CRBasic program name,
program signature, data-table name.
Line 2 – Data-Field Names
Lists the name of individual data fields. If the field is an element of an array,
the name will be followed by a comma-separated list of subscripts within
parentheses that identifies the array index. For example, a variable named
“values” that is declared as a two-by-two array, i.e.,
Public Values(2,2)
will be represented by four field names: “values(1,1)”, “values(1,2)”,
“values(2,1)”, and “values(2,2)”. Scalar (non-array) variables will not have
subscripts.
Line 3 – Data Units
Includes the units associated with each field in the record. If no units are
programmed in the CR1000 CRBasic program, an empty string is entered for
that field.
Line 4 – Data-Processing Descriptors
Entries describe what type of processing was performed in the CR1000 to
produce corresponding data, e.g., Smp indicates samples, Min indicates
minima. If there is no recognized processing for a field, it is assigned an
empty string. There will be one descriptor for each field name given on
Header Line 2.
Record Element 1 – Timestamp
Data without timestamps are usually meaningless. Nevertheless, the
380
Section 8. Operation
TableFile() instruction optionally includes timestamps in some formats.
Record Element 2 – Record Number
Record numbers are optionally provided in some formats as a means to
ensure data integrity and provide an up-count data field for graphing
operations. The maximum record number is &hffffffff (a 32-bit number),
then the record number sequence restarts at zero. The CR1000 reports back
to the datalogger support software 31 bits, or a maximum of &h7fffffff, then
it restarts at 0. For example, if the record number increments once a second,
restart at zero will occur about once every 68 years (yes, years).
8.3.3
Resetting the CR1000
A reset is referred to as a "memory reset." Be sure to backup the current CR1000
configuration before a reset in case you need to revert to the old settings.
The following features are available for complete or selective reset of CR1000
memory:
x
x
x
x
Full memory reset
Program send reset
Manual data-table reset
Formatting memory drives
8.3.3.1 Full Memory Reset
Full memory reset occurs when an operating system is sent to the CR1000 using
DevConfig or when entering 98765 in the Status table field FullMemReset. A
full memory reset does the following:
x
x
x
x
x
x
x
Clears and formats CPU: drive (all program files erased)
Clears SRAM data tables
Clears Status-table elements
Restores settings to default
Initializes system variables
Clears communication memory
Recompiles current program
Full memory reset does not affect the CRD: drive directly. Subsequent user
program uploads, however, can erase CRD:.
Operating systems can also be sent using the program Send feature in datalogger
support software (p. 95). A full reset does not occur in this case. Beginning with
CR1000 operating system v.16, settings and registers in the Status table are
preserved when sending a subsequent operating system by this method; data
tables are erased. Rely on this feature only with an abundance of caution when
sending an OS to CR1000s in remote, expensive to get to, or difficult-to-access
locations.
8.3.3.2 Program Send Reset
Final-memory (p. 515) data are erased when user programs are uploaded, unless
preserve / erase data options are used. Preserve / erase data options are presented
when sending programs using File Control Send (p. 515) command and CRBasic
381
Section 8. Operation
Editor Compile, Save and Send (p. 511). See Preserving Data at Program Send (p.
127) for a more-detailed discussion of preserve / erase data at program send.
8.3.3.3 Manual Data-Table Reset
Data-table memory is selectively reset from
x
x
Support software Station Status (p. 529) command
CR1000KD Keyboard Display: Data | Reset Data Tables
8.3.3.4 Formatting Drives
CPU:, USR:, USB:, and CRD: drives can be formatted individually. Formatting a
drive erases all files on that drive. If the currently running user program is found
on the drive to be formatted, the program will cease running and any SRAM data
associated with the program are erased. Drive formatting is performed through
datalogger support software (p. 654) Format (p. 515) command.
8.3.4
File Management
As summarized in table File Control Functions (p. 382), files in CR1000 memory
(program, data, CAL, image) can be managed or controlled with datalogger
support software (p. 95), CR1000 Web API (p. 423), or CoraScript (p. 510). Use of
CoraScript is described in the LoggerNet software manual, which is available at
www.campbellsci.com. More information on file attributes that enhance
datalogger security, see the Security (p. 92) section.
Table 89. File-Control Functions
File-Control Functions
Accessed Through
1
Sending programs to the CR1000
2
3
Program Send , File Control Send , DevConfig , keyboard or
powerup.ini with a Campbell Scientific mass storage device or
memory card
Datalogger)
4,5
, web API (p. 423) HTTPPut (Sending a File to a
2
File Control ;power-up with Campbell Scientific mass storage
Setting program file attributes. See File Attributes (p. 383)
5
6
device or memory card , FileManage() instruction , web API
FileControl
3
Sending an OS to the CR1000. Reset CR1000 settings.
3
DevConfig Send OS tab; DevConfig File Control tab;
5
Campbell Scientific mass storage device or memory card
1
Sending an OS to the CR1000. Preserve CR1000 settings.
3
Send ; DevConfig File Control tab; power-up with Campbell
Scientific mass storage device or memory card with default.cr1
5
file , web API HTTPPut (Sending a File to a Datalogger)
2
Formatting CR1000 memory drives
File Control , power-up with Campbell Scientific mass storage
5
device or memory card , web API FileControl
7
Retrieving programs from the CR1000
Prescribes the disposition (preserve or delete) of old data files
on Campbell Scientific mass storage device or memory card
382
2
Retrieve , File Control , keyboard with Campbell Scientific
4
mass storage device or memory card , web API NewestFile
2
File Control , power-up with Campbell Scientific mass storage
5
device or memory card , web API (p. 423) FileControl
Section 8. Operation
Table 89. File-Control Functions
File-Control Functions
Accessed Through
2
File Control , power-up with Campbell Scientific mass storage
Deleting files from memory drives
5
device or memory card , web API FileControl
2
Stopping program execution
File Control , web API FileControl
Renaming a file
FileRename()
Time-stamping a file
FileTime()
List files
File Control , FileList() , web API ListFiles
Create a data file from a data table
TableFile()
JPEG files manager
CR1000KD Keyboard Display , LoggerNet | PakBusGraph, web
API NewestFile
Hiding files
Web API FileControl
Encrypting files
Web API FileControl
Abort program on power-up
Hold DEL down on datalogger keypad
1
2
3
4
5
6
7
6
6
2
6
6
Datalogger support software (p. 95) Program Send (p. 524) command
Datalogger support software File Control (p. 515) utility
Device Configuration Utility (DevConfig) (p. 111) software
Manual with Campbell Scientific mass storage device or memory card. See Data Storage (p. 374)
Automatic with Campbell Scientific mass storage device or memory card and Powerup.ini. See Power-up (p. 386)
CRBasic instructions (commands). See Data-Table Declarations (p. 540) and File Management (p. 382) and CRBasic Editor Help
Datalogger support software Retrieve (p. 515) command
8.3.4.1 File Attributes
A feature of program files is the file attribute. Table CR1000 File Attributes (p. 383)
lists available file attributes, their functions, and when attributes are typically
used. For example, a program file sent with the support software Program Send
(p. 524) command, runs a) immediately ("run now"), and b) when power is cycled
on the CR1000 ("run on power-up'). This functionality is invoked because
Program Send (p. 524) sets two CR1000 file attributes on the program file, i.e.,
Run Now and Run on Power-up. When together, Run Now and Run on Powerup are tagged as Run Always.
Note Activation of the run-on-power-up file can be prevented by holding down
the Del key on the CR1000KD Keyboard Display while the CR1000 is powering
up.
Table 90. CR1000 File Attributes
Attribute
Function
Attribute for Programs Sent to CR1000 with:
a) Send (p. 515)
Run Always
(run on power-up +
run now)
Runs now and on
power-up.
1
2
b) File Control with Run Now & Run on Power-up
selected.
c) Campbell Scientific mass storage device or
3
memory card power-up using commands 1 & 13
383
Section 8. Operation
Table 90. CR1000 File Attributes
Attribute
Function
Attribute for Programs Sent to CR1000 with:
(see table Powerup.ini Commands (p. 388) ).
2
Run on Power-up
Runs only on
power-up
a) File Control with Run on Power-up checked.
b) Campbell Scientific mass storage device or
3
memory card power-up using command 2 (see table
Powerup.ini Commands (p. 388) ).
2
a) File Control with Run Now checked.
b) Campbell Scientific mass storage device or
Run Now
1
2
Runs only when
file sent to CR1000
3
memory card power-up using commands 6 & 14
(see the table Powerup.ini Commands (p. 388) ).
However, if the external storage device remains
connected, the program loads again from the external
storage device.
Support software program Send (p. 515) command. See software Help.
Support software File Control (p. 515). See software Help & Preserving Data at Program Send
(p. 127).
3
Automatic on power-up of CR1000 with Campbell Scientific mass storage device or memory
card and Powerup.ini. See Power-up (p. 386).
8.3.4.2 Files Manager
FilesManager := { "(" pakbus-address "," name-prefix "," numberfiles ")" }.
pakbus-address := number. ; 0 < number < 4095
name-prefix := string.
number_files := number. ; 0 <= number < 10000000
This setting specifies the numbers of files of a designated type that are saved
when received from a specified node. There can be up to four such settings. The
files are renamed by using the specified file name optionally altered by a serial
number inserted before the file type. This serial number is used by the datalogger
to know which file to delete after the serial number exceeds the specified number
of files to retain. If the number of files is 0, the serial number is not inserted. A
special node PakBus address of 3210 can be used if the files are sent with FTP
protocol, or 3211 if the files are written with CRBasic.
Note This setting will operate only on a file whose name is not a null string.
Example:
(129,CPU:NorthWest.JPG,2)
(130,CRD:SouthEast.JPG,20)
(130,CPU:Message.TXT,0)
In the example above, *.JPG files from node 129 are named
CPU:NorthWestnnn.JPG and two files are retained , and *.JPG files from node
130 are named CRD:SouthEastnnn.JPG, while 20 files are retained. The nnn
serial number starts at 1 and will advance beyond nine digits. In this example, all
*.TXT files from node 130 are stored with the name CPU:Message.Txt, with no
384
Section 8. Operation
serial number inserted.
A second instance of a setting can be configured using the same node PakBus
address and same file type, in which case two files will be written according to
each of the two settings. For example,
(55,USR:photo.JPG,100)
(55:USR:NewestPhoto.JPG,0)
will store two files each time a JPG file is received from node 55. They will be
named USR:photonnn.JPG and USR:NewestPhoto.JPG. This feature is used
when a number of files are to be retained, but a copy of one file whose name
never changes is also needed. The second instance of the file can also be
serialized and used when a number of files are to be saved to different drives.
Entering 3212 as the PakBus address activates storing IP trace information to a
file. The "number of files" parameter specifies the size of the file. The file is a
ring file, so the newest tracing is kept. The boundary between newest and oldest
is found by looking at the time stamps of the tracing. Logged information may be
out of sequence.
Example:
(3212, USR:IPTrace.txt, 5000)
This syntax will create a file on the USR: drive called IPTrace.txt that will grow
to approximately 5 KB in size, and then new data will begin overwriting old data.
8.3.4.3 Data Preservation
Associated with file attributes is the option to preserve data in CR1000 memory
when a program is sent. This option applies to data table SRAM, CompactFlash®
(CF), and datalogger support software (p. 512) cache data (p. 511). Depending on the
application, retention of data files when a program is downloaded may be
desirable. When sending a program to the CR1000 with datalogger support
software Send command, data are always deleted before the program runs. When
the program is sent using support software File Control Send (p. 515) command or
CRBasic Editor Compile, Save and Send (p. 511) command, options to preserve
(not erase) or not preserve (erase) data are presented. The logic in the table DataPreserve Options (p. 386) summarizes the disposition of CR1000 data depending on
the data preservation option selected.
385
Section 8. Operation
Table 91. Data-Preserve Options
if "Preserve data if no table changed"
keep CF data from overwritten program
if current program = overwritten program
keep CPU data
keep cache data
else
erase CPU data
erase cache data
end if
end if
if "erase
erase
erase
erase
end if
CF data"
CF data from overwritten program
CPU data
cache data
8.3.4.4 Powerup.ini File — Details
Uploading a CR1000 OS (p. 522) file or user-program file in the field can be
challenging, particularly during weather extremes. Heat, cold, snow, rain,
altitude, blowing sand, and distance to hike influence how easily programming
with a laptop or palm PC may be. An alternative is to carry the file to the field on
a light-weight, external-memory device such as a USB: (p. 653) or CRD: (p. 653) drive.
Steps to download the new OS or CRBasic program from an external-memory
drive are:
1. Place a text file named powerup.ini, with appropriate commands entered in the
file, on the external-memory device along with the new OS or CRBasic
program file.
2. Connect the external device to the CR1000 and then cycle power to the
datalogger.
This simple process results in the file uploading to the CR1000 with optional run
attributes, such as Run Now, Run on Power Up, or Run Always set for
individual files. Simply copying a file to a specified drive with no run attributes,
or to format a memory drive, is also possible. Command options for powerup.ini
options also allow final-data memory management on CF cards comparable to the
datalogger support software (p. 95) File Control feature.
Options for powerup.ini also allow final-data memory management comparable
File Control (p. 515). Note that the CRD: drive has priority over the USB: drive.
Caution Test the powerup.ini file and procedures in the lab before going to the
field. Always carry a laptop or mobile device (with datalogger support software)
into difficult- or expensive-to-access places as backup.
Powerup.ini commands include the following functions:
x
x
x
386
Sending programs to the CR1000.
Optionally setting run attributes of CR1000 program files.
Sending an OS to the CR1000.
Section 8. Operation
x
x
Formatting memory drives.
Deleting data files associated with the previously running program.
When power is connected to the CR1000, it searches for powerup.ini and
executes the command(s) prior to compiling a program. Powerup.ini performs
three operations:
1. Copies the program file to a memory drive
2. Optionally sets a file run attribute (Run Now, Run on Power Up, or Run
Always) for the program file.
3. Optionally deletes data files stored from the overwritten (just previous)
program.
4. Formats a specified drive.
Execution of powerup.ini takes precedence during CR1000 power-up. Although
powerup.ini sets file attributes for the uploaded programs, its presence on a drive
does not allow those file attributes to control the power-up process. To avoid
confusion, either remove the external drive on which powerup.ini resides or
delete the file after the power-up operation is complete.
8.3.4.4.1 Creating and Editing Powerup.ini
Powerup.ini is created with a text editor on a PC, then saved on a memory drive
of the CR1000. The file is saved to the memory drive, along with the operating
system or user program file, using the datalogger support software (p. 654) File
Control | Send (p. 515) command.
Note Some text editors (such as MicroSoft® WordPad®) will attach header
information to the powerup.ini file causing it to abort. Check the text of a
powerup.ini file in the CR1000 with the CR1000KD Keyboard Display to see
what the CR1000 actually sees.
Comments can be added to the file by preceding them with a single-quote
character ('). All text after the comment mark on the same line is ignored.
Syntax
Syntax for powerup.ini is:
Command,File,Device
where,
x
Command is one of the numeric commands in table Powerup.ini Commands
x
File is the accompanying operating system or user program file. File name
can be up to 22 characters long.
Device is the CR1000 memory drive to which the accompanying operating
system or user program file is copied (usually CPU:). If left blank or with an
invalid option, default device will be CPU:. Use the same drive designation
as the transporting external device if the preference is to not copy the file.
x
(p. 388).
387
Section 8. Operation
Table 92. Powerup.ini Commands and Applications
Command
Run always, preserve data
2
Run on power-up
Copies the specified program to the
designated drive. The program specified
in command 2 will be set to Run Always
unless command 6 or 14 is used to set a
separate Run Now program.
5
Format
Formats the designated drive.
Run now, preserve data
Copies the specified program to the
designated drive and sets the run attribute
of the program to Run Now. Data on a
CF card from the previously running
program will be preserved.
7
Copy file to specified drive with no run
attributes. Use to copy Include (p. 518) or
program support files to the CPU: drive
before copying the program file to run.
Copies the specified file to the designated
drive with no run attributes.
9
Load OS (File = .obj)
6
1
1
13
14
Run always, erase data
Copies the specified program to the
designated drive and sets the run attribute
of the program to Run Always. Data
on a CF card from the previously running
program will be erased.
Run now, erase files
Copies the specified program to the
designated drive and sets the run attribute
to Run Now. Data on a CF card from
the previously running program will be
erased.
By using PreserveVariables() instruction in the CRBasic program, with commands 1 and 6, data and variables can be preserved.
Example Power-up.ini Files
Table 93. Powerup.ini Example. Code Format and Syntax
'Code format and syntax
'Command = numeric power-up command
'File = file associated with the action
'Device = device to which File is copied. Defaults to CPU:
'Command,File,Device
13,Write2CRD_2.cr1,cpu:
Table 94. Powerup.ini Example. Run Program on Power-up
'Copy program file pwrup.cr1 from the external drive to CPU:
'File will run only when CR1000 powered-up later.
2,pwrup.cr1,cpu:
388
Applications
Copies the specified program to the
designated drive and sets the run attribute
of the program to Run Always. Data
on a CF card from the previously running
program will be preserved.
1
1
Description
Section 8. Operation
Table 95. Powerup.ini Example. Format the USR: Drive
'Format the USR: drive
5,,usr:
Table 96. Powerup.ini Example. Send OS on Power-up
'Load an operating system (.obj) file into FLASH as the new OS.
9,CR1000.Std.28.obj
Table 97. Powerup.ini Example. Run Program from USB: Drive
'A program file is carried on an external USB: drive.
'Do not copy program file from USB:
'Run program always, erase data.
13,toobigforcpu.cr1,usb:
Table 98. Powerup.ini Example. Run Program Always, Erase Data
'Run a program file always, erase data.
13,pwrup_1.cr1,cpu:
Table 99. Powerup.ini Example. Run Program Now, Erase Data
'Run a program file now, erase data now.
14,run.cr1,cpu:
Power-up.ini Execution
After powerup.ini is processed, the following rules determine what CR1000
program to run:
x
x
x
If the run-now program is changed, then it is the program that runs.
If no change is made to run-now program, but run-on-power-up program is
changed, the new run-on-power-up program runs.
If neither run-on-power-up nor run-now programs are changed, the previous
run-on-power-up program runs.
8.3.4.5 File Management Q & A
Q: How do I hide a program file on the CR1000 without using the CRBasic
FileManage() instruction?
A: Use the CoraScript (p. 510) File-Control command, or the web API (p. 423)
FileControl command.
8.3.5
File Names
The maximum size of the file name that can be stored, run as a program, or FTP
transferred in the CR1000 is 59 characters. If the name is longer than 59
characters, an Invalid Filename error is displayed. If several files are stored, each
with a long filename, memory allocated to the root directory can be exceeded
before the actual memory of storing files is exceeded. When this occurs, an
"insufficient resources or memory full" error is displayed.
8.3.6
File-System Errors
Table File System Error Codes (p. 390) lists error codes associated with the CR1000
file system. Errors can occur when attempting to access files on any of the
389
Section 8. Operation
available drives. All occurrences are rare, but they are most likely to occur when
using the CRD: drive.
Table 100. File System Error Codes
Error Code
390
Description
1
Invalid format
2
Device capabilities error
3
Unable to allocate memory for file operation
4
Max number of available files exceeded
5
No file entry exists in directory
6
Disk change occurred
7
Part of the path (subdirectory) was not found
8
File at EOF
9
Bad cluster encountered
10
No file buffer available
11
Filename too long or has bad chars
12
File in path is not a directory
13
Access permission, opening DIR or LABEL as file, or trying to open file as
DIR or mkdir existing file
14
Opening read-only file for write
15
Disk full (can't allocate new cluster)
16
Root directory is full
17
Bad file ptr (pointer) or device not initialized
18
Device does not support this operation
19
Bad function argument supplied
20
Seek out-of-file bounds
21
Trying to mkdir an existing dir
22
Bad partition sector signature
23
Unexpected system ID byte in partition entry
24
Path already open
25
Access to uninitialized ram drive
26
Attempted rename across devices
27
Subdirectory is not empty
31
Attempted write to Write Protected disk
32
No response from drive (Door possibly open)
33
Address mark or sector not found
34
Bad sector encountered
35
DMA memory boundary crossing error
Section 8. Operation
Table 100. File System Error Codes
Error Code
8.3.7
Description
36
Miscellaneous I/O error
37
Pipe size of 0 requested
38
Memory-release error (relmem)
39
FAT sectors unreadable (all copies)
40
Bad BPB sector
41
Time-out waiting for filesystem available
42
Controller failure error
43
Pathname exceeds _MAX_PATHNAME
Memory Q & A
Q: Can a user create a program too large to fit on the CPU: drive (>100k) and
have it run from the CRD: drive (memory card)?
A: The program does not run from the memory card. However, a very large
program (too large to fit on the CPU: drive) can be compiled into CR1000 main
memory from the card if the binary form of the compiled program does not
exceed the available main memory (p. 370).
8.4
Data Retrieval and Telecommunications — Details
Related Topics:
‡Data Retrieval and Telecommunications — Quickstart (p. 45)
‡Data Retrieval and Telecommunications — Overview (p. 88)
‡Data Retrieval and Telecommunications — Details (p. 391)
‡Data Retrieval and Telecommunication Peripherals — Lists (p. 651)
Telecommunications, in the context of CR1000 operation, is the movement of
information between the CR1000 and another computing device, usually a PC.
The information can be data, program, files, or control commands.
Telecommunication systems require three principal components: hardware, carrier
signal, and protocol. For example, a common way to communicate with the
CR1000 is with PC200W software by way of a PC COM port. In this example,
hardware are the PC COM port, CR1000 RS-232 port, and a serial cable. The
carrier signal is RS-232, and the protocol is PakBus®. Of these three, you will
most often be required to choose only the hardware, since carrier signal and
protocol are transparent in most applications.
Systems usually require a single type of hardware and carrier signal. Some
applications, however, require hybrid systems of two or more hardware and signal
carriers.
Contact a Campbell Scientific application engineer for assistance in configuring a
telecommunication system.
Synopses of software to support telecommunication devices and protocols are
found in the appendix Support Software (p. 654). Of special note is Network
Planner, a LoggerNet client designed to simplify the configuration of PakBus
telecommunication networks.
391
Section 8. Operation
8.4.1
Protocols
The CR1000 communicates with datalogger support software (p. 95) and other
Campbell Scientific dataloggers (p. 645) using the PakBus (p. 522) protocol. See the
section Alternate Telecommunications — Details (p. 407) for information on other
supported protocols, such as TCP/IP, Modbus, etc.
8.4.2
Conserving Bandwidth
Some telecommunication services, such as satellite networks, can be expensive to
send and receive information. Best practices for reducing expense include:
x
x
x
x
x
8.4.3
Declare Public only those variables that need to be public.
Be conservative with use of string variables and string variable sizes. Make
string variables as big as they need to be and no more; remember the
minimum is actually 24 bytes. Declare string variables Public and sample
string variables into data tables only as needed.
When using GetVariables() / SendVariables() to send values between
dataloggers, put the data in an array and use one command to get the multiple
values. Using one command to get 10 values from an array and swath of 10
is much more efficient (requires only 1 transaction) than using 10 commands
to get 10 single values (requires 10 transactions).
Set the CR1000 to be a PakBus router only as needed. When the CR1000 is a
router, and it connects to another router like LoggerNet, it exchanges routing
information with that router and, possibly (depending on your settings), with
other routers in the network.
Set PakBus beacons and verify intervals properly. For example, there is no
need to verify routes every five minutes if communications are expected only
every 6 hours.
Initiating Telecommunications (Callback)
Telecommunication sessions are usually initiated by a PC. Once
telecommunication is established, the PC issues commands to send programs, set
clocks, collect data, etc. Because data retrieval is managed by the PC, several PCs
can have access to a CR1000 without disrupting the continuity of data. PakBus®
allows multiple PCs to communicate with the CR1000 simultaneously when
proper telecommunication networks are installed.
Typically, the PC initiates telecommunications with the CR1000 with datalogger
support software (p. 654). However, some applications require the CR1000 to call
back the PC (initiate telecommunications). This feature is called 'Callback'.
Special LoggerNet (p. 654) features enable the PC to receive calls from the CR1000.
For example, if a fruit grower wants a frost alarm, the CR1000 can contact him by
calling a PC, sending an email, text message, or page, or calling him with
synthesized-voice over telephone. Callback has been used in applications
including Ethernet, land-line telephone, digital cellular, and direct connection.
Callback with telephone is well documented in CRBasic Editor Help (search term
"callback"). For more information on other available Callback features, manuals
for various telecommunication hardware may discuss Callback options. Contact a
Campbell Scientific application engineer for the latest information in Callback
392
Section 8. Operation
applications.
Caution When using the ComME communication port with non-PakBus
protocols, incoming characters can be corrupted by concurrent use of the CS I/O
for SDC communications. PakBus communications use a low-level protocol
(pause / finish / ready sequence) to stop incoming data while SDC occurs.
Non-PakBus communications include TCP/IP protocols, ModBus, DNP3, and
generic, CRBasic-driven use of CS I/O.
Though usually unnoticed, a short burst of SDC communications occurs at powerup and other times when the datalogger is reset, such as when compiling a
program or changing settings that require recompiling. This activity is the
datalogger querying to see if the CR1000KD Keyboard Display is available.
When DevConfig and PakBus Graph retrieve settings, the CR1000 queries to
determine what SDC devices are connected. Results of the query can be seen in
the DevConfig and PakBusGraph settings tables. SDC queries occur whether or
not an SDC device is attached.
8.5
PakBus® Communications — Details
Related Topics:
‡PakBus® Communications — Overview (p. 88)
‡PakBus® Communications — Details (p. 393)
‡PakBus® Communications — Instructions (p. 584)
‡PakBus Networking Guide (available at www.campbellsci.com/manuals
(http://www.campbellsci.com/manuals))
The CR1000 communicates with computers or other Campbell Scientific
dataloggers with PakBus. PakBus is a proprietary telecommunication protocol
similar in concept to IP (Internet protocol). PakBus allows compatible Campbell
Scientific dataloggers and telecommunication peripherals to seamlessly join a
PakBus network.
Read More This section is provided as a primer to PakBus communications.
More information is available in the appendicies Peer-to-Peer PakBus
Communications (p. 584) and Status/Settings/DTI: PakBus Information and the
PakBus Networking Guide, available at www.campbellsci.com.
8.5.1
PakBus Addresses
CR1000s are assigned PakBus® address 1 as a factory default. Networks with
more than a few stations should be organized with an addressing scheme that
guarantees unique addresses for all nodes. One approach, demonstrated in figure
PakBus Network Addressing (p. 394) , is to assign single-digit addresses to the first
tier of nodes, double-digit to the second tier, triple-digit to the third, etc. Note that
each node on a branch starts with the same digit. Devices, such as PCs, with
addresses greater than 4000 are given special administrative access to the network
PakBus addresses are set using DevConfig, PakBusGraph, CR1000 Status table,
or with an CR1000KD Keyboard Display. DevConfig (Device Configuration
Utility) is the primary settings editor. It requires a hardwire serial connection to a
393
Section 8. Operation
PC and allows backup of settings on the PC hard drive. PakBusGraph is used over
a telecommunication link to change settings, but has no provision for backup.
Caution Care should be taken when changing PakBus® addresses with
PakBusGraph or in the Status table. If an address is changed to an unknown
value, a field visit with a laptop and DevConfig may be required to discover the
unknown address.
8.5.2
Nodes: Leaf Nodes and Routers
x
x
x
A PakBus® network consists of two to 4093 linked nodes.
One or more leaf nodes and routers can exist in a network.
Leaf nodes are measurement devices at the end of a branch of the PakBus
network.
o
o
x
Leaf nodes can be linked to any router.
A leaf node cannot route packets but can originate or receive them.
Routers are measurement or telecommunication devices that route packets to
other linked routers or leaf nodes.
o
o
o
Routers can be branch routers. Branch routers only know as neighbors
central routers, routers in route to central routers, and routers one level
outward in the network.
Routers can be central routers. Central routers know the entire network.
A PC running LoggerNet is typically a central router.
Routers can be router-capable dataloggers or communication devices.
The CR1000 is a leaf node by factory default. It can be configured as a router by
setting IsRouter in its Status table to 1 or True. The network shown in figure
PakBus Network Addressing (p. 394) contains six routers and eight leaf nodes.
8.5.2.1 Router and Leaf-Node Configuration
Consult the appendix Router and Leaf-Node Hardware for a table of available
PakBus® leaf-node and router devices. LoggerNet is configured by default as a
router and can route datalogger- to-datalogger communications.
Figure 102.
394
PakBus Network Addressing
Section 8. Operation
Table 101. PakBus Leaf-Node and Router Device Configuration
Network
Device
Description
PakBus
Leaf Node
CR200X
Datalogger
‡
CR6 CS I/O
Port
Datalogger
‡
‡
CR800
Datalogger
‡
‡
CR1000
Datalogger
‡
‡
CR3000
Datalogger
‡
‡
CR5000
Datalogger
‡
‡
LoggerNet
Software
CR6 Ethernet
Port
Network link
NL100
Serial port
network link
NL115
NL120
8.5.3
PakBus
Router
PakBus
Aware
‡
‡
‡
Peripheral port
network link
‡
1
Peripheral port
network link
Transparent
‡
1
NL200
Serial port
network link
NL240
Wireless
network link
MD485
Multidrop
RF401,
RF430,
RF450
Radio
CC640
Camera
SC105
Serial interface
‡
SC32B
Serial interface
‡
SC932A
Serial interface
‡
COM220
Telephone
modem
‡
COM310
Telephone
modem
‡
SRM-5A
Short-haul
modem
‡
‡
‡
‡
‡
‡
‡
Linking PakBus Nodes: Neighbor Discovery
New terms (see Nodes: Leaf Nodes and Routers (p. 394) ):
x
x
node
link
395
Section 8. Operation
x
x
x
x
x
x
x
x
neighbor
neighbor-filters
hello
hello-exchange
hello-message
hello-request
CVI
beacon
To form a network, nodes must establish links with neighbors (neighbors are
adjacent nodes). Links are established through a process called discovery.
Discovery occurs when nodes exchange hellos. A hello-exchange occurs during a
hello-message between two nodes.
8.5.3.1 Hello-Message
A hello-message is a two-way exchange between nodes to negotiate a neighbor
link. A hello-message is sent out in response to one or both of either a beacon or
a hello-request.
8.5.3.2 Beacon
A beacon is a one-way broadcast sent by a node at a specified interval telling all
nodes within hearing that a hello-message can be sent. If a node wishes to
establish itself as a neighbor to the beaconing node, it will then send a hellomessage to the beaconing node. Nodes already established as neighbors will not
respond to a beacon.
8.5.3.3 Hello-Request
A hello-request is a one-way broadcast. All nodes hearing a hello-request
(existing and potential neighbors) will issue a hello-message to negotiate or renegotiate a neighbor relationship with the broadcasting node.
8.5.3.4 Neighbor Lists
PakBus devices in a network can be configured with a neighbor list. The CR1000
sends out a hello-message to each node in the list whose CVI (p. 511) has expired at
a random interval1. If a node responds, a hello-message is exchanged and the node
becomes a neighbor.
Neighbor filters dictate which nodes are neighbors and force packets to take
routes specified by the network administrator. LoggerNet, which is a PakBus
node, derives its neighbor filter from link information in the LoggerNet Setup
device map.
1
Interval is a random number of seconds between the interval and two times the interval, where the
interval is the CVI (if non-zero) or 300 seconds if the CVI setting is set to zero.
8.5.3.5 Adjusting Links
PakBusGraph, a client of LoggerNet, is particularly useful when testing and
adjusting PakBus routes. Paths established by way of beaconing may be
redundant and vary in reliability. Redundant paths can provide backup links in the
396
Section 8. Operation
event the primary path fails. Redundant and unreliable paths can be eliminated by
activating neighbor-filters in the various nodes and by disabling some beacons.
8.5.3.6 Maintaining Links
Links are maintained by means of the CVI (p. 511). The CVI can be specified in
each node with the Verify Interval setting in DevConfig (ComPorts Settings).
The following rules apply:
Note During the hello-message, a CVI must be negotiated between two
neighbors. The negotiated CVI is the lesser of the first node's CVI and 6/5ths of
the neighbor's CVI.
x
x
x
x
If Verify Interval = 0, then CVI = 2.5 x Beacon Interval
If Verify Interval = 60, then CVI = 60 seconds
If Beacon Interval = 0 and Verify Interval = 0, then CVI = 300 seconds
If the router or master does not hear from a neighbor for one CVI, it begins
again to send a hello-message to that node at the random interval.
Users should base the Verify Interval setting on the timing of normal
communications such as scheduled LoggerNet-data collections or datalogger-todatalogger communications. The idea is to not allow the CVI to expire before
normal communications. If the CVI expires, the devices will initiate helloexchanges in an attempt to regain neighbor status, which will increase traffic on
the network.
8.5.4
PakBus Troubleshooting
Various tools and methods have been developed to assist in troubleshooting
PakBus networks.
8.5.4.1 Link Integrity
With beaconing or neighbor-filter discovery, links are established and verified
using relatively small data packets (hello-messages). When links are used for
regular telecommunications, however, longer messages are used. Consequently, a
link may be reliable enough for discovery using hello-messages but unreliable
with the longer messages or packets. This condition is most common in radio
networks, particularly when maximum packet size is >200.
PakBus communications over marginal links can often be improved by reducing
the size of the PakBus packets with the Max Packet Size setting in DevConfig
Advanced tab. Best results are obtained when the maximum packet sizes in both
nodes are reduced.
8.5.4.1.1 Automatic Packet-Size Adjustment
The BMP5 file-receive transaction allows the BMP5 client (LoggerNet) to specify
the size of the next fragment of the file that the CR1000 sends.
Note PakBus uses the file-receive transaction to get table definitions from the
datalogger.
Because LoggerNet must specify a size for the next fragment of the file, it uses
whatever size restrictions that apply to the link.
397
Section 8. Operation
Hence, the size of the responses to the file-receive commands that the CR1000
sends is governed by the Max Packet Size setting for the datalogger as well as
that of any of its parents in the LoggerNet network map. Note that this calculation
also takes into account the error rate for devices in the link.
BMP5 data-collection transaction does not provide any way for the client to
specify a cap on the size of the response message. This is the main reason why the
Max Packet Size setting exists. The CR1000 can look at this setting at the point
where it is forming a response message and cut short the amount of data that it
would normally send if the setting limits the message size.
8.5.4.2 Ping (PakBus)
Link integrity can be verified with the following procedure by using
PakBusGraph Ping Node. Nodes can be pinged with packets of 50, 100, 200, or
500 bytes.
Note Do not use packet sizes greater than 90 when pinging with 100 mW radio
modems and radio enabled dataloggers. See the appendix Data Retrieval and
Telecommunication Peripherals — Lists (p. 651).
Pinging with ten repetitions of each packet size will characterize the link. Before
pinging, all other network traffic (scheduled data collections, clock checks, etc.)
should be temporarily disabled. Begin by pinging the first layer of links
(neighbors) from the PC / LoggerNet router, then proceed to nodes that are more
than one hop away. Table PakBus Link-Performance Gage (p. 398) provides a linkperformance gage.
Table 102. PakBus Link-Performance Gage
500 byte
Pings Sent
Successes
Link Status
10
10
excellent
10
9
good
10
7-8
adequate
10
<7
marginal
8.5.4.3 Traffic Flow
Keep beacon intervals as long as possible with higher traffic (large numbers of
nodes and / or frequent data collection). Long beacon intervals minimize
collisions with other packets and resulting retries. The minimum recommended
Beacon Interval setting is 60 seconds. If communication traffic is high, consider
setting beacon intervals of several minutes. If data throughput needs are great,
maximize data bandwidth by creating some branch routers, or by eliminating
beacons altogether and setting up neighbor filters.
8.5.5
LoggerNet Network-Map Configuration
As shown in figure Flat Map (p. 399) and figure Tree Map (p. 399), the essential
element of a PakBus network device map in LoggerNet is the PakBusPort. After
adding the root port (COM, IP, etc), add a PakBusPort and the dataloggers.
398
Section 8. Operation
Figure 103.
Flat Map
Figure 104.
Tree Map
The difference between the two configurations is that the flat map configures the
router with static routes that report that all of the dataloggers are neighbours to the
server. The tree map configures static routes wherein "CR1000" is configured as
a neighbour and "CR1000_2", "CR1000_3", and "CR1000_4" are configured to
use "CR1000" as the router. Deeper nesting, while allowed, is meaningless in
terms of PakBus because PakBus does not allow dictation of the entire
communication path. You can specify the router address for only the first hop.
Within the server, dynamically discovered routes take precedence over static
routes, so once the network is learned, communications will work smoothly.
However, having the correct static route to begin is often crucial because an
attempt to ring a false neighbor can time out before routing can be discovered
from the real neighbor.
Stated another way, use the tree configuration when communication requires
routers. The shape of the map serves to disallow a direct LoggerNet connection to
CR1000_2 and CR1000_3, and it implies constrained routes that will probably be
established by user-installed neighbor filters in the routers. This assumes that
LoggerNet beacons are turned off. Otherwise, with a default address of 4094,
LoggerNet beacons will penetrate the neighbor filter of any in-range node.
399
Section 8. Operation
8.5.6
PakBus LAN Example
To demonstrate PakBus networking, a small LAN (Local Area Network) of
CR1000s can be configured as shown in figure Configuration and Wiring of
PakBus LAN (p. 400). A PC running LoggerNet uses the RS-232 port of the first
CR1000 to communicate with all CR1000s. All LoggerNet functions, such as
send programs, monitor measurements, and collect data, are available to each
CR1000. CR1000s can also be programmed to exchange data with each other
(the data exchange feature is not demonstrated in this example).
8.5.6.1 LAN Wiring
Use three-conductor cable to connect CR1000s as shown in figure Configuration
and Wiring of CR1000 LAN (p. 400). Cable length between any two CR1000s must
be less than 25 feet (7.6 m). COM1 Tx (transmit) and Rx (receive) are CR1000
terminals C1 and C2, respectively; COM2 Tx and Rx are terminals C3 and C4,
respectively. Tx from a CR1000 is connected to Rx of an adjacent CR1000.
Figure 105.
400
Configuration and Wiring of PakBus LAN
Section 8. Operation
8.5.6.2 LAN Setup
Configure CR1000s before connecting them to the LAN:
1. Start Device Configuration Utility (DevConfig). Click on Device Type: select
CR1000. Follow on-screen instructions to power CR1000s and connect them
to the PC. Close other programs that may be using the PC COM port, such as
LoggerNet, PC400, PC200W, HotSync, etc.
2. Click on the Connect button at the lower left.
3. Set settings using DevConfig as outlined in table PakBus-LAN Example
Datalogger-Communication Settings (p. 402). Leave unspecified settings at
default values. Example DevConfig screen captures are shown in figure
DevConfig Deployment | Datalogger Tab (p. 401) through figure DevConfig
Deployment | Advanced Tab (p. 402). If the CR1000s are not new, upgrading the
operating system or setting factory defaults before working this example is
advised.
Figure 106.
DevConfig Deployment Tab
401
Section 8. Operation
402
Figure 107.
DevConfig Deployment | ComPorts Settings Tab
Figure 108.
DevConfig Deployment | Advanced Tab
Section 8. Operation
Table 103. PakBus-LAN Example Datalogger-Communication Settings
6RIWZDUHĺ
Device Configuration Utility (DevConfig)
7DEĺ
Deployment
Sub-7DEĺ
Datalogger
6HWWLQJĺ
PakBus Adr
Sub-6HWWLQJĺ
COM1
Baud Rate
'DWDORJJHUĻ
Is Router
COM2
1
Baud Rate
Neighbors
Begin:
End:
CR1000_1
1
115.2K Fixed
2
2
115.2K Fixed
CR1000_2
2
115.2K Fixed
1
1
Disabled
CR1000_3
3
115.2K Fixed
1
1
115.2K Fixed
CR1000_4
4
115.2K Fixed
3
3
Disabled
1
Advanced
ComPort Settings
1
Neighbors
Begin:
End:
3
4
Yes
No
4
4
Yes
No
Setup can be simplified by setting all neighbor lists to Begin: 1 End: 4.
8.5.6.3 LoggerNet Setup
Figure 109.
LoggerNet Network-Map Setup: COM port
In LoggerNet Setup, click Add Root and add a ComPort. Then Add a
PakBusPort, and (4) CR1000 dataloggers to the device map as shown in figure
LoggerNet Device-Map Setup (p. 403).
403
Section 8. Operation
Figure 110.
LoggerNet Network-Map Setup: PakBusPort
As shown in figure LoggerNet Device Map Setup: PakBusPort (p. 404), set the
PakBusPort maximum baud rate to 115200. Leave other settings at the defaults.
Figure 111.
LoggerNet Network-Map Setup: Dataloggers
As shown in figure LoggerNet Device-Map Setup: Dataloggers (p. 404), set the
PakBus® address for each CR1000 as listed in table PakBus-LAN Example
Datalogger-Communication Settings (p. 402).
404
Section 8. Operation
8.5.7
Route Filters
The Route Filters setting restricts routing or processing of some PakBus message
types so that a "state changing" message can only be processed or forwarded by
this CR1000 if the source address of that message is in one of the source ranges
and the destination address of that message is in the corresponding destination
range. If no ranges are specified (the default), the CR1000 will not apply any
routing restrictions. "State changing" message types include set variable, table
reset, file control send file, set settings, and revert settings.
For example, if this setting was set to a value of (4094, 4094, 1, 10), the CR1000
would only process or forward "state changing" messages that originated from
address 4094 and were destined to an address in the range between one and ten.
This is displayed and parsed using the following formal syntax:
route-filters := { "(" source-begin "," source-end ","
dest-begin "," dest-end ")" }.
source-begin := uint2. ; 1 < source-begin <= 4094
source-end := uint2. ; source-begin <= source-end <= 4094
dest-begin := uint2. ; 1 < dest-begin <= 4094
dest-end
:= uint2. ; dest-begin <= dest-end <= 4094
8.5.8
PakBusRoutes
PakBusRoutes() lists the routes (in the case of a router), or the router neighbors
(in the case of a leaf node), that were known to the CR1000 at the time the setting
was read. Each route is represented by four components separated by commas
and enclosed in parentheses:
PakBusRoutes(port, via neighbor adr, pakbus adr, response time)
Descriptions of PakBusRoutes() parameters:
port
Specifies a numeric code for the port the router will use:
Table 104. Router Port Numbers
Port Description
Numeric Code
ComRS232
1
ComME
2
ComSDC6 (Com310)
3
ComSDC7
4
ComSDC8
5
ComSDC9 (Com320)
6
ComSDC10
7
ComSDC11
8
Com1 (C1,C2)
9
Com2 (C3,C4)
10
Com3 (C5,C6)
11
405
Section 8. Operation
Com4 (C7,C8)
IP
1
12
101,102,…
1
,IWKHYDOXHRIWKHSRUWQXPEHULV•WKHFRQQHFWLRQLVPDGHWKURXJK3DN%XV7&3HLWKHUE\
the CR1000 executing a TCPOpen() instruction or by having a connection made to the
PakBus/TCP CR1000 service.
via neighbor adr
Specifies address of neighbor / router to be used to send messages for this
route. If the route is for a neighbor, this value is the same as the address.
pakbus adr
For a router, specifies the address the route reaches. If a leaf node, this is 0.
response time
For a router, specifies time in milliseconds that is allowed for the route. If a
leaf node, this is 0.
8.5.9
Neighbors
Settings Editor name: Neighbors Allowed xxx
Array of integers indicating PakBus neighbors for comumunication ports:
RS-232, ME, SDC7, SDC8, SDC10, SDC11
Com1 (C1,C2)
Com2 (C3,C4)
Com3 (C5,C6)
Com4 (C7,C8)
This setting specifies, for a given port, the explicit list of PakBus node addresses
that the CR1000 will accept as neighbors. If the list is empty (the default
condition), any node is accepted as a neighbor. This setting will not affect the
acceptance of a neighbor if that neighbor address is greater than 3999. The formal
syntax for this setting follows:
neighbor := { "(" range-begin "," range-end ")" }.
range-begin := pakbus-address. ;
range-end := pakbus-address.
pakbus-address := number. ; 0 < number < 4000
If more than 10 neighbors are in the allowed list and the beacon interval is 0, the
beacon interval is changed to 60 seconds and beaconing is used for neighbor
discovery instead of directed hello requests that consume communication
memory.
8.5.10 PakBus Encryption
Two PakBus devices can exchange encrypted commands and data. Encryption
uses the AES-128 algorithm. Routers and other leaf nodes do not need to be set
for encryption. The CR1000 has a setting accessed through DevConfig (p. 111) that
sets it to send and receive only encrypted commands and data. LoggerNet (p. 655),
likewise, has a setting attached to the specific station that enables it to send and
406
Section 8. Operation
receive only encrypted commands and data. Header level information needed for
routing is not encrypted. An encrypted CR1000 can also communicate with an
unencrypted datalogger. Use an EncryptExempt() instruction in the CRBasic
program to define one or more PakBus addresses to which encrypted messages
will not be sent.
Campbell Scientific products supporting PakBus encryption include the
following:
x
x
x
x
x
LoggerNet 4.2
CR1000 datalogger (OS26 and later)
CR3000 datalogger (OS26 and later)
CR800 series dataloggers (OS26 and later)
CR1000 series dataloggers (OS1 and later)
Device Configuration Utility (DevConfig) v. 2.04 and later
x
Network Planner v. 1.6 and later.
Portions of the protocol to which PakBus encryption is applied include:
x
x
All BMP5 messages
All settings related messages
Note Basic PakBus messages such as Hello, Hello Request, Send Neighbors,
Get Neighbors, and Echo are NOT encrypted.
The PakBus encryption key can be set in the CR1000 datalogger through:
x
x
x
x
DevConfig Deployment tab
DevConfig Settings Editor tab
PakBusGraph settings editor dialog
Keyboard display
Be careful to record the encryption key in a secure location. If the encryption key
is lost, it needs to be reset. Reset the key on the keyboard display by deleting the
bullet characters that appear in the field, then enter the new key.
Note Encryption key cannot be set through the CRBasic program.
Setting the encryption key in datalogger support software (p. 512) (LoggerNet 4.2
and higher):
x
x
Applies to CR1000, CR3000, CR800 series, and CR1000 dataloggers, and
PakBus routers, and PakBus port device types.
Can be set through the LoggerNet Set Up screen, Network Planner, or
CoraScript (only CoraScript can set the setting for a PakBus port).
Note Setting the encryption key for a PakBus port device will force all messages
it sends to use encryption.
8.6
Alternate Telecommunications — Details
Related Topics:
‡Alternate Telecommunications — Overview (p. 90)
‡Alternate Telecommunications — Details (p. 407)
407
Section 8. Operation
The CR1000 communicates with datalogger support software (p. 95) and other
Campbell Scientific dataloggers (p. 645) using the PakBus (p. 522) protocol. Modbus,
DNP3, TCP/IP, and several industry-specific protocols are also supported. CAN
bus is supported when using the Campbell Scientific SDM-CAN (p. 651)
communication module.
8.6.1
DNP3 — Details
Related Topics:
‡DNP3 — Overview (p. 91)
‡DNP3 — Details (p. 408)
This section is slated for a major update early in 2015.
8.6.1.1 DNP3 Introduction
The CR1000 is DNP3 SCADA compatible. DNP3 is a SCADA protocol primarily
used by utilities, power-generation and distribution networks, and the water- and
wastewater-treatment industry.
Distributed Network Protocol (DNP) is an open protocol used in applications to
ensure data integrity using minimal bandwidth. DNP implementation in the
CR1000 is DNP3 Level-2 Slave Compliant with some of the operations found in a
Level-3 implementation. A standard CR1000 program with DNP instructions will
take arrays of real time or processed data and map them to DNP arrays in integer
or binary format. The CR1000 responds to any DNP master with the requested
data or sends unsolicited responses to a specific DNP master. DNP
communications are supported in the CR1000 through the RS-232 port, COM1,
COM2, COM3, or COM4, or over TCP, taking advantage of multiple
communication options compatible with the CR1000, e.g., RF, cellular phone,
satellite. DNP3 state and history are preserved through power and other resets in
non-volatile memory.
DNP SCADA software enables CR1000 data to move directly into a database or
display screens. Applications include monitoring weather near power transmission
lines to enhance operational decisions, monitoring and controlling irrigation from
a wastewater-treatment plant, controlling remote pumps, measuring river flow,
and monitoring air movement and quality at a power plant.
8.6.1.2 Programming for DNP3
CRBasic example Implementation of DNP3 (p. 410) lists CRBasic code to take
Iarray() analog data and Barray() binary data (status of control port 5) and map
them to DNP arrays. The CR1000 responds to a DNP master with the specified
data or sends unsolicited responses to DNP Master 3.
8.6.1.2.1 Declarations (DNP3 Programming)
Table DNP3 Implementation — Data Types Required to Store Data in Public
Tables for Object Groups (p. 409) shows object groups supported by the CR1000
DNP implementation, and the required data types. A complete list of groups and
variations is available in CRBasic Editor Help for DNPVariable().
408
Section 8. Operation
Table 105. DNP3 Implementation — Data Types Required to Store
Data in Public Tables for Object Groups
Data Type
Group
Description
Boolean
1
Binary input
2
Binary input change
10
Binary output
12
Control block
30
Analog input
32
Analog change event
40
Analog output status
41
Analog output block
50
Time and date
51
Time and date CTO
Long
8.6.1.2.2 CRBasic Instructions (DNP3)
Complete descriptions and options of commands are available in CRBasic Editor
Help.
DNP()
Sets the CR1000 as a DNP slave (outstation/server) with an address and DNP3dedicated COM port. Normally resides between BeginProg and Scan(), so it is
executed only once. Example at CRBasic example Implementation of DNP3 (p.
410), line 20.
Syntax
DNP(ComPort, BaudRate, DNPSlaveAddr)
DNPVariable()
Associates a particular variable array with a DNP object group. When the master
polls the CR1000, it returns all the variables specified along with their specific
groups. Also used to set up event data, which is sent to the master whenever the
value in the variable changes. Example at CRBasic example Implementation of
DNP3 (p. 410), line 24.
Syntax
DNPVariable(Source, Swath, DNPObject, DNPVariation, DNPClass,
DNPFlag, DNPEvent, DNPNumEvents)
DNPUpdate()
Determines when DNP slave (outstation/server) will update its arrays of DNP
elements. Specifies the address of the DNP master to which are sent unsolicited
responses (event data). Must be included once within a Scan() / NextScan for the
DNP slave to update its arrays. Typically placed in a program after the elements
in the array are updated. The CR1000 will respond to any DNP master regardless
of its address.
409
Section 8. Operation
Syntax
DNPUpdate (DNPSlaveAddr,DNPMasterAddr)
8.6.1.2.3 Programming for DNP3 Data Acquisition
As shown in CRBasic example Implementation of DNP3 (p. 410), program the
CR1000 to return data when polled by the DNP3 master using the following three
actions:
1. Place DNP() at the beginning of the program between BeginProg and Scan().
Set COM port, baud rate, and DNP3 address.
2. Setup the variables to be sent to the master using DNPVariable(). Dual
instructions cover static (current values) and event (previous ten records) data.
o
For analog measurements:
DNPVariable(Variable_Name,Swath,30,2,0,&B00000000,0,0)
DNPVariable(Variable_Name,Swath,32,2,3,&B00000000,0,10)
o
For digital measurements (control ports):
DNPVariable(Variable_Name,Swath,1,2,0,&B00000000,0,0)
DNPVariable(Variable_Name,Swath,32,2,3,&B00000000,0,10)
3. Place DNPUpdate() after Scan(), inside the main scan. The DNP3 master is
notified of any change in data each time DNPUpdate() runs; e.g., for a 10
second scan, the master is notified every 10 seconds.
CRBasic Example 66.
Implementation of DNP3
'This program example demonstrates a basic implementation of DNP3 in the CR1000. The CR1000
'is programmed to return data over IP when polled by the DNP3 master. Essential elements
'of the program are as follows:
'
'
'
'
'
'
'
'
'For analog measurements:
'DNPVariable(Variable_Name,Swath,30,2,0,&B00000000,0,0)
'DNPVariable(Variable_Name,Swath,32,2,3,&B00000000,0,10)
'
'
'
'For digital measurements (control ports):
'DNPVariable(Variable_Name,Swath,1,2,0,&B00000000,0,0)
'DNPVariable(Variable_Name,Swath,32,2,3,&B00000000,0,10)
'
'
'
410
1. DNP() instruction is placed at the beginning of the program between BeginProg
and Scan(). COM port, baud rate, and DNP3 address are set.
2. Variables are set up to be sent to the master using DNPVariable(). Dual instructions
cover static data (current values) and event data (previous ten records). Following
are the sets of dual instructions for analog and digital measurements:
3. DNPUpdate() is placed after Scan(), inside the main scan. The DNP3 master is
notified of any change in data each time DNPUpdate() runs. For example, for a 10
second scan, the master is notified every 10 seconds.
Section 8. Operation
Public IArray(4) As Long
Public BArray(2) As Boolean
Public
Public
Public
Public
Units
Units
Units
Units
WindSpd
WindDir
Batt_Volt
PTemp_C
WindSpd=meter/Sec
WindDir=Degrees
Batt_Volt=Volts
PTemp_C=Deg C
'Main Program
BeginProg
'DNP communication over IP at 115.2kbps. CR1000 DNP address is 1.
DNP(20000,115200,1)
'DNPVariable(Source,Swath,DNPObject,DNPVariation,DNPClass,DNPFlag,DNPEvent,DNPNumEvents)
DNPVariable(IArray,4,30,2,0,&B00000000,0,0)
'Object group 30, variation 2 is used to return analog data when the CR1000
'is polled. Flag is set to an empty 8 bit number(all zeros), DNPEvent is a
'reserved parameter and is currently always set to zero. Number of events is
'only used for event data.
DNPVariable(IArray,4,32,2,3,&B00000000,0,10)
DNPVariable(BArray,2,1,1,0,&B00000000,0,0)
DNPVariable(BArray,2,2,1,1,&B00000000,0,1)
Scan(1,Sec,1,0)
'Wind Speed & Direction Sensor measurements WS_ms and WindDir:
PulseCount(WindSpd,1,1,1,3000,2,0)
IArray(1) = WindSpd * 100
BrHalf(WindDir,1,mV2500,1,Vx1,1,2500,True,0,_60Hz,355,0)
If WindDir>=360 Then WindDir=0
IArray(2) = WindDir * 100
'Default Datalogger Battery Voltage measurement Batt_Volt:
Battery(Batt_Volt)
IArray(3) = Batt_Volt * 100
'Wiring Panel Temperature measurement PTemp_C:
PanelTemp(PTemp_C,_60Hz)
IArray(1) =PTemp_C
PortGet(Barray(1),5)
'Update DNP arrays and send unsolicited requests to DNP Master address 3
DNPUpdate(2,3)
NextScan
EndProg
8.6.2
Modbus — Details
Related Topics:
‡Modbus — Overview (p. 91)
‡Modbus — Details (p. 411)
411
Section 8. Operation
The CR1000 supports Modbus master and Modbus slave communications for
inclusion in Modbus SCADA networks. Modbus is a widely used SCADA
communication protocol that facilitates exchange of information and data between
computers / HMI software, instruments (RTUs) and Modbus-compatible sensors.
The CR1000 communicates with Modbus over RS-232, RS-485 (with a RS-232 to
RS-485 adapter), and TCP.
Modbus systems consist of a master (PC), RTU / PLC slaves, field instruments
(sensors), and the communication-network hardware. The communication port,
baud rate, data bits, stop bits, and parity are set in the Modbus driver of the master
and / or the slaves. The Modbus standard has two communication modes, RTU
and ASCII. However, CR1000s communicate in RTU mode exclusively.
Field instruments can be queried by the CR1000. Because Modbus has a set
command structure, programming the CR1000 to get data from field instruments
is much simpler than from serial sensors. Because Modbus uses a common bus
and addresses each node, field instruments are effectively multiplexed to a
CR1000 without additional hardware.
A CR1000 goes into sleep mode after 40 seconds of communication inactivity.
Once asleep, two packets are required before the CR1000 will respond. The first
packet awakens the CR1000; the second packet is received as data. CR1000s,
through DevConfig or the Status table (see the appendix Status Table and Settings
(p. 603) ) can be set to keep communication ports open and awake, but at higher
power usage.
8.6.2.1 Modbus Terminology
Table Modbus to Campbell Scientific Equivalents (p. 412) lists terminology
equivalents to aid in understanding how CR1000s fit into a SCADA system.
Table 106. Modbus to Campbell Scientific Equivalents
Modbus Domain
Data Form
Campbell Scientific
Domain
Coils
Single bit
Ports, flags, boolean variables
Digital registers
16 bit word
Floating point variables
Input registers
16 bit word
Floating point variables
Holding registers
16 bit word
Floating point variables
RTU / PLC
CR1000
Master
Usually a computer
Slave
Usually a CR1000
Field instrument
Sensor
8.6.2.1.1 Glossary of Modbus Terms
Term. coils (00001 to 09999)
Originally, "coils" referred to relay coils. In CR1000s, coils are exclusively
terminals configured for control, software flags, or a Boolean-variable array.
412
Section 8. Operation
Terminal configured for control are inferred if parameter 5 of the
ModbusSlave() instruction is set to 0. Coils are assigned to Modbus
registers 00001 to 09999.
Term. digital registers 10001 to 19999
Hold values resulting from a digital measurement. Digital registers in the
Modbus domain are read-only. In the Campbell Scientific domain, the
leading digit in Modbus registers is ignored, and so are assigned together to a
single Dim- or Public-variable array (read / write).
Term. input registers 30001 to 39999
Hold values resulting from an analog measurement. Input registers in the
Modbus domain are read-only. In the Campbell Scientific domain, the
leading digit in Modbus registers is ignored, and so are assigned together to a
single Dim- or Public- variable array (read / write).
Term. holding registers 40001 to 49999
Hold values resulting from a programming action. Holding registers in the
Modbus domain are read / write. In the Campbell Scientific domain, the
leading digit in Modbus registers is ignored, and so are assigned together to a
single Dim or Public variable array (read / write).
Term. RTU / PLC
Remote Telemetry Units (RTUs) and Programmable Logic Controllers
(PLCs) were at one time used in exclusive applications. As technology
increases, however, the distinction between RTUs and PLCs becomes more
blurred. A CR1000 fits both RTU and PLC definitions.
8.6.2.2 Programming for Modbus
8.6.2.2.1 Declarations (Modbus Programming)
Table CRBasic Ports, Flags, Variables, and Modbus Registers (p. 413) shows the
linkage between terminals configured for control, flags and Boolean variables and
Modbus registers. Modbus does not distinguish between terminals configured for
control, flags, or Boolean variables. By declaring only terminals configured for
control, or flags, or Boolean variables, the declared feature is addressed by
default. A typical CRBasic program for a Modbus application will declare
variables and ports, or variables and flags, or variables and Boolean variables.
413
Section 8. Operation
Table 107. CRBasic Ports, Flags, Variables, and, Modbus Registers
Example CRBasic
Declaration
CR1000 Feature
Terminal configured for
control
Equivalent Example
Modbus Register
Public Port(8)
00001 to 00009
Flag
Public Flag(17)
00001 to 00018
Boolean variable
Public ArrayB(56) as
Boolean
00001 to 00057
Variable
Public ArrayV(20)
1
1
40001 to 40041 or
1
30001 to 30041
1
Because of byte-number differences, each CR1000 domain variable translates to two Modbus
domain input / holding registers.
8.6.2.2.2 CRBasic Instructions (Modbus)
Complete descriptions and options of commands are available in CRBasic Editor
Help.
ModbusMaster()
Sets up a CR1000 as a Modbus master to send or retrieve data from a Modbus
slave.
Syntax
ModbusMaster(ResultCode, ComPort, BaudRate, ModbusAddr,
Function, Variable, Start, Length, Tries, TimeOut)
ModbusSlave()
Sets up a CR1000 as a Modbus slave device.
Syntax
ModbusSlave(ComPort, BaudRate, ModbusAddr, DataVariable,
BooleanVariable)
MoveBytes()
Moves binary bytes of data into a different memory location when translating bigendian to little-endian data. See the appendix Endianness (p. 643).
Syntax
MoveBytes(Dest, DestOffset, Source, SourceOffset, NumBytes)
8.6.2.2.3 Addressing (ModbusAddr)
Modbus devices have a unique address in each network. Addresses range from 1
to 247. Address 0 is reserved for universal broadcasts. When using the NL240,
use the same number as the Modbus and PakBus address.
414
Section 8. Operation
8.6.2.2.4 Supported Modbus Function Codes
Modbus protocol has many function codes. CR1000 commands support the
following.
Table 108. Supported Modbus Function Codes
Code
Name
Description
01
Read coil/port status
Reads the on/off status of discrete output(s) in the
ModBusSlave
02
Read input status
Reads the on/off status of discrete input(s) in the
ModBusSlave
03
Read holding registers
Reads the binary contents of holding register(s) in
the ModBusSlave
04
Read input registers
Reads the binary contents of input register(s) in
the ModBusSlave
05
Force single coil/port
Forces a single coil/port in the ModBusSlave to
either on or off
06
Write single register
Writes a value into a holding register in the
ModBusSlave
15
Force multiple coils/ports
Forces multiple coils/ports in the ModBusSlave to
either on or off
16
Write multiple registers
Writes values into a series of holding registers in
the ModBusSlave
8.6.2.2.5 Reading Inverse-Format Modbus Registers
Some Modbus devices require reverse byte order words (CDAB vs. ABCD). This
can be true for either floating point, or integer formats. Since a slave CR1000
uses the ABCD format, either the master has to make an adjustment, which is
sometimes possible, or the CR1000 needs to output reverse-byte order words. To
reverse the byte order in the CR1000, use the MoveBytes() instruction as shown
in the sample code below.
for i = 1 to k
MoveBytes(InverseFloat(i),2,Float(i),0,2)
MoveBytes(InverseFloat(i),0,Float(i),2,2)
next
In the example above, InverseFloat(i) is the array holding the inverse-byte
ordered word (CDAB). Array Float(i) holds the obverse-byte ordered word
(ABCD).
See the appendix Endianness (p. 643).
8.6.2.3 Troubleshooting (Modbus)
Test Modbus functions on the CR1000 with third party Modbus software. Further
information is available at the following links:
x
x
x
www.simplyModbus.ca/FAQ.htm
www.Modbus.org/tech.php
www.lammertbies.nl/comm/info/modbus.html
415
Section 8. Operation
8.6.2.4 Modbus over IP
Modbus over IP functionality is an option with the CR1000. Contact Campbell
Scientific for details.
8.6.2.5 Modbus Q and A
Q: Can Modbus be used over an RS-232 link, 7 data bits, even parity, one stop
bit?
A: Yes. Precede ModBusMaster() / ModBusSlave() with SerialOpen() and set
the numeric format of the COM port with any of the available formats, including
the option of 7 data bits, even parity. SerialOpen() and ModBusMaster() can be
used once and placed before Scan().
Concatenating two Modbus long 16-bit variables to one Modbus long 32 bit
number.
8.6.2.6 Converting Modbus 16-Bit to 32-Bit Longs
Concatenation of two Modbus long 16-bit variables to one Modbus long 32
bit number is shown in the following example.
CRBasic Example 67.
Concatenating Modbus Long Variables
'This program example demonstrates concatenation (splicing) of Long data type variables
'for Modbus operations. Program is compatible with the following or later operating systems:
' CR800 OS v.3
' CR1000 OS v.12
' CR3000 OS v.5
'
'NOTE: The CR1000 uses big-endian word order.
'Declarations
Public Combo As Long
Public Register(2) As Long
Public Result
'Aliases used for clarification
Alias Register(1) = Register_LSW
Alias Register(2) = Register_MSW
'Variable to hold the combined 32-bit
'Array holds two 16-bit ModBus long
'variables
'Register(1) = Least Significant Word
'Register(2) = Most Significant Word
'Holds the result of the ModBus master
'query
'Least significant word.
'Most significant word.
BeginProg
'If you use the numbers below (un-comment them first)
'Combo is read as 131073 decimal
'Register_LSW=&h0001 'Least significant word.
'Register_MSW=&h0002 ' Most significant word.
416
Section 8. Operation
Scan(1,Sec,0,0)
'In the case of the CR1000 being the ModBus master then the
'ModbusMaster instruction would be used (instead of fixing
'the variables as shown between the BeginProg and SCAN instructions).
ModbusMaster(Result,COMRS232,-115200,5,3,Register(),-1,2,3,100)
'MoveBytes(DestVariable,DestOffset,SourceVariable,SourceOffSet,
'NumberOfBytes)
MoveBytes(Combo,2, Register_LSW,2,2)
MoveBytes(Combo,0, Register_MSW,2,2)
NextScan
EndProg
8.6.3
TCP/IP — Details
Related Topics:
‡TCP/IP — Overview (p. 91)
‡TCP/IP — Details (p. 423)
‡TCP/IP — Instructions (p. 593)
‡TCP/IP Links — List (p. 652)
The following TCP/IP protocols are supported by the CR1000 when using
network-links (p. 652) that use the resident IP stack or when using a cell modem with
the PPP/IP key enabled. More information on some of these protocols is in the
following sections.
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
x
DHCP
DNS
FTP
HTML
HTTP
Micro-serial server
NTCIP
NTP
PakBus over TCP/IP
Ping
POP3
SMTP
SNMP
Telnet
Web API (p. 423)
XML
The most up-to-date information on implementing these protocols is contained in
CRBasic Editor Help. For a list of CRBasic instructions, see the appendix
TCP/IP (p. 593).
Read More Specific information concerning the use of digital-cellular modems
for TCP/IP can be found in Campbell Scientific manuals for those modems. For
information on available TCP/IP/PPP devices, refer to the appendix Network
Links (p. 652) for model numbers. Detailed information on use of TCP/IP/PPP
devices is found in their respective manuals (available at www.campbellsci.com
http://www.campbellsci.com) and CRBasic Editor Help.
417
Section 8. Operation
8.6.3.1 PakBus Over TCP/IP and Callback
Once the hardware has been configured, basic PakBus® communication over
TCP/IP is possible. These functions include the following:
x
x
x
x
x
Sending programs
Retrieving programs
Setting the CR1000 clock
Collecting data
Displaying the current record in a data table
Data callback and datalogger-to-datalogger communications are also possible over
TCP/IP. For details and example programs for callback and datalogger-todatalogger communications, see the network-link manual. A listing of networklink model numbers is found in the appendix Network Links (p. 652).
8.6.3.2 Default HTTP Web Server
The CR1000 has a default home page built into the operating system. The home
page can be accessed using the following URL:
http:\\ipaddress:80
Note Port 80 is implied if the port is not otherwise specified.
As shown in the figure, Preconfigured HTML Home Page (p. 291), this page
provides links to the newest record in all tables, including the Status table, Public
table, and data tables. Links are also provided for the last 24 records in each data
table. If fewer than 24 records have been stored in a data table, the link will
display all data in that table.
Newest-Record links refresh automatically every 10 seconds. Last 24-Records
link must be manually refreshed to see new data. Links will also be created
automatically for any HTML, XML, and JPEG files found on the CR1000 drives.
To copy files to these drives, choose File Control from the datalogger support
software (p. 512) menu.
418
Section 8. Operation
Figure 112.
Preconfigured HTML Home Page
8.6.3.3 Custom HTTP Web Server
Although the default home page cannot be accessed for editing, it can be replaced
with the HTML code of a customized web page. To replace the default home
page, save the new home page under the name default.html and copy it to the
datalogger. It can be copied to a CR1000 drive with File Control. Deleting
default.html will cause the CR1000 to use the original, default home page.
The CR1000 can be programmed to generate HTML or XML code that can be
viewed by a web browser. CRBasic example HTML (p. 293) shows how to use the
CRBasic instructions WebPageBegin() / WebPageEnd and HTTPOut() to
create HTML code. Note that for HTML code requiring the use of quotation
marks, CHR(34) is used, while regular quotation marks are used to define the
beginning and end of alphanumeric strings inside the parentheses of the
HTTPOut() instruction. For additional information, see the CRBasic Editor Help.
In this example program, the default home page is replaced by using
WebPageBegin to create a file called default.html. The new default home page
created by the program appears as shown in the figure Home Page Created using
WebPageBegin() Instruction (p. 292).
The Campbell Scientific logo in the web page comes from a file called
SHIELDWEB2.JPG that must be transferred from the PC to the CR1000 CPU:
drive using File Control in the datalogger support software.
A second web page, shown in figure Customized Numeric-Monitor Web Page (p.
"monitor.html" was created by the example program that contains links
to the CR1000 data tables.
293) called
419
Section 8. Operation
420
Figure 113.
Home Page Created Using WebPageBegin() Instruction
Figure 114.
Customized Numeric-Monitor Web Page
Section 8. Operation
CRBasic Example 68.
Custom Web Page HTML
'This program example demonstrates the creation of a custom web page that resides in the
'CR1000. In this example program, the default home page is replaced by using WebPageBegin to
'create a file called default.html. The graphic in the web page (in this case, the Campbell
'Scientific logo) comes from a file called SHIELDWEB2.JPG. The graphic file must be copied to
'the CR1000 CPU: drive using File Control in the datalogger support software. A second web
'page is created that contains links to the CR1000 data tables.
'NOTE: The "_" character used at the end of some lines allows a code statement to be wrapped
'to the next line.
Dim Commands As String * 200
Public Time(9), RefTemp,
Public Minutes As String, Seconds As String, Temperature As String
DataTable(CRTemp,True,-1)
DataInterval(0,1,Min,10)
Sample(1,RefTemp,FP2)
Average(1,RefTemp,FP2,False)
EndTable
'Default HTML Page
WebPageBegin("default.html",Commands)
HTTPOut("<html>")
HTTPOut("<style>body {background-color: oldlace}</style>")
HTTPOut("<body><title>Campbell Scientific CR1000 Datalogger</title>")
HTTPOut("<h2>Welcome To the Campbell Scientific CR1000 Web Site!</h2>")
HTTPOut("<tr><td style=" + CHR(34) +"width: 290px" + CHR(34) + ">")
HTTPOut("<a href=" + CHR(34) + "http://www.campbellsci.com" + CHR(34) + ">")
HTTPOut("<img src="+ CHR(34) +"/CPU/SHIELDWEB2.jpg"+ CHR(34) + "width=" + _
CHR(34) +"128"+CHR(34)+"height="+CHR(34)+"155"+ CHR(34) + "class=" + _
CHR(34) +"style1"+ CHR(34) +"/></a></td>")
HTTPOut("<p><h2> Current Data:</h2></p>")
HTTPOut("<p>Time: " + time(4) + ":" + minutes + ":" + seconds + "</p>")
HTTPOut("<p>Temperature: " + Temperature + "</p>")
HTTPOut("<p><h2> Links:</h2></p>")
HTTPOut("<p><a href="+ CHR(34) +"monitor.html"+ CHR(34)+">Monitor</a></p>")
HTTPOut("</body>")
HTTPOut("</html>")
WebPageEnd
'Monitor Web Page
WebPageBegin("monitor.html",Commands)
HTTPOut("<html>")
HTTPOut("<style>body {background-color: oldlace}</style>")
HTTPOut("<body>")
HTTPOut("<title>Monitor CR1000 Datalogger Tables</title>")
HTTPOut("<p><h2>CR1000 Data Table Links</h2></p>")
HTTPOut("<p><a href="+ CHR(34) + "command=TableDisplay&table=CRTemp&records=10" + _
CHR(34)+">Display Last 10 Records from DataTable CR1Temp</a></p>")
HTTPOut("<p><a href="+ CHR(34) + "command=NewestRecord&table=CRTemp"+ CHR(34) + _
">Current Record from CRTemp Table</a></p>")
HTTPOut("<p><a href="+ CHR(34) + "command=NewestRecord&table=Public"+ CHR(34) + _
">Current Record from Public Table</a></p>")
421
Section 8. Operation
HTTPOut("<p><a href="+ CHR(34) + "command=NewestRecord&table=Status" + CHR(34) + _
">Current Record from Status Table</a></p>")
HTTPOut("<br><p><a href="+ CHR(34) +"default.html"+ CHR(34) + ">Back to the Home Page _
</a></p>")
HTTPOut("</body>")
HTTPOut("</html>")
WebPageEnd
BeginProg
Scan(1,Sec,3,0)
PanelTemp(RefTemp,250)
RealTime(Time())
Minutes = FormatFloat(Time(5),"%02.0f")
Seconds = FormatFloat(Time(6),"%02.0f")
Temperature = FormatFloat(RefTemp, "%02.02f")
CallTable(CRTemp)
NextScan
EndProg
8.6.3.4 FTP Server
The CR1000 automatically runs an FTP server. This allows Windows® Explorer®
to access the CR1000 file system with FTP, with drives on the CR1000 being
mapped into directories or folders. The root directory on the CR1000 can be any
drive, but the USR: drive is usually preferred. USR: is a drive created by
allocating memory in the USR: Drive Size box on the Deployment | Advanced
tab of the CR1000 service in DevConfig. Files can be copied / pasted between
drives. Files can be deleted through FTP.
8.6.3.5 FTP Client
The CR1000 can act as an FTP client to send a file or get a file from an FTP
server, such as another datalogger or web camera. This is done using the
CRBasic FTPClient() instruction. Refer to a manual for a Campbell Scientific
network link (see the appendix Network Links (p. 652) ), available at
www.campbellsci.com, or CRBasic Editor Help for details and sample programs.
8.6.3.6 Telnet
Telnet is used to access the same commands that are available through the support
software terminal emulator (p. 530). Start a Telnet session by opening a DOS
command prompt and type in:
Telnet xxx.xxx.xxx.xxx <Enter>
where xxx.xxx.xxx.xxx is the IP address of the network device connected to the
CR1000.
8.6.3.7 SNMP
Simple Network Management Protocol (SNMP) is a part of the IP suite used by
NTCIP and RWIS for monitoring road conditions. The CR1000 supports SNMP
when a network device is attached.
422
Section 8. Operation
8.6.3.8 Ping (IP)
Ping can be used to verify that the IP address for the network device connected to
the CR1000 is reachable. To use the Ping tool, open a command prompt on a
computer connected to the network and type in:
ping xxx.xxx.xxx.xxx <Enter>
where xxx.xxx.xxx.xxx is the IP address of the network device connected to the
CR1000.
8.6.3.9 Micro-Serial Server
The CR1000 can be configured to allow serial communication over a TCP/IP port.
This is useful when communicating with a serial sensor over Ethernet with microserial server (third-party serial to Ethernet interface) to which the serial sensor is
connected. See the network-link manual and the CRBasic Editor Help for the
TCPOpen() instruction for more information. Information on available network
links is available in the appendix Network Links (p. 652).
8.6.3.10 Modbus TCP/IP
The CR1000 can perform Modbus communication over TCP/IP using the Modbus
TCP/IP interface. To set up Modbus TCP/IP, specify port 502 as the ComPort in
the ModBusMaster() and ModBusSlave() instructions. See the CRBasic Editor
Help for more information. See Modbus (p. 411).
8.6.3.11 DHCP
When connected to a server with a list of IP addresses available for assignment,
the CR1000 will automatically request and obtain an IP address through the
Dynamic Host Configuration Protocol (DHCP). Once the address is assigned, use
DevConfig, PakBusGraph, Connect, or the CR1000KD Keyboard Display to look
in the CR1000 Status table to see the assigned IP address. This is shown under
the field name IPInfo.
8.6.3.12 DNS
The CR1000 provides a Domain Name Server (DNS) client that can query a DNS
server to determine if an IP address has been mapped to a hostname. If it has, then
the hostname can be used interchangeably with the IP address in some datalogger
instructions.
8.6.3.13 SMTP
Simple Mail Transfer Protocol (SMTP) is the standard for e-mail transmissions.
The CR1000 can be programmed to send e-mail messages on a regular schedule
or based on the occurrence of an event.
8.6.3.14 Web API
The CR1000 web API (Application Programming Interface) is a series of URL (p.
532) commands that manage CR1000 resources. The API facilitates the following
functions:
423
Section 8. Operation
x
Data Management
Collect data
x
Control — CRBasic program language logic can allow remote access to
many control functions by means of changing the value of a variable.
Set variables / flags / ports
x
Clock Functions — Clock functions allow a web client to monitor and set the
host CR1000 real time clock. Read the Time Syntax section for more
information.
Set CR1000 clock
x
File Management — Web API commands allow a web client to manage files
on host CR1000 memory drives. Camera image files are examples of
collections often needing frequent management.
Send programs
Send files
Collect files
API commands are also used with Campbell Scientific’s RTMC web server
datalogger support software (p. 95). The following documentation focuses on API
use with the CR1000. A full discussion of use of the API commands with RTMC
is available in CRBasic Editor Help, which is one of several programs available
for PC to CR1000 support (p. 95).
8.6.3.14.1
Authentication
The CR1000 passcode security scheme described in the Security (p. 92) section is
not considered sufficiently robust for API use because of the following:
1. the security code is plainly visible in the URI, so it can be compromised by
eavesdropping or viewing the monitor.
2. the range of valid security codes is 1 to 65534, so the security code can be
compromised by brute force attacks.
Instead, Basic Access Authentication, which is implemented in the API, should be
used with the CR1000. Basic Access Authentication uses an encrypted user
account file, .csipasswd, which is placed on the CPU: drive of the CR1000.
Four levels of access are available through Basic Access Authentication:
x
x
x
x
all access denied (Level 0)
all access allowed (Level 1)
set variables allowed (Level 2)
read-only access (Level 3)
Multiple user accounts and security levels can be defined. A file named
.csipasswd is created on the CR1000 CPU: drive and edited in the Device
Configuration Utility (DevConfig) (p. 111) software Net Services tab, Edit
.csipasswd File button. When in Datalogger .csipasswd File Editor dialog box,
pressing Apply after entering user names and passwords encrypts .csipasswd and
saves it to the CR1000 CPU: drive. A check box is available to set the file as
hidden. If hidden when saved, the file cannot be accessed for editing.
424
Section 8. Operation
If access to the CR1000 web server is attempted without correct security
credentials, the CR1000 returns the error 401 Authorization Required. This
error prompts the web browser or client to display a user name and password
request dialog box. If .csipasswd is blank or does not exist, the user name
defaults to anonymous with no password, and the security level defaults to readonly (default security level can be changed in DevConfig). If an invalid user
name or password is entered in .csipasswd, the CR1000 web server will default to
the level of access assigned to anonymous.
The security level associated with the user name anonymous, affects only API
commands. For example, the API command SetValueEx will not function when
the API security level is set to read-only, but the CRBasic parameter SetValue in
the WebPageBegin() instruction will function. However, if .csipasswd sets a
user name other than anonymous and sets a password, security will be active on
API and CRBasic commands. For example, if a numeric pass code is set in the
CR1000 Status table (see Security (p. 92) section), and .csipasswd does not exist,
then the pass code must be entered to use the CRBasic parameter SetValue. If
.csipasswd does exist, a correct user name and password will override the pass
code.
8.6.3.14.2
Command Syntax
API commands follow the syntax,
ip_adr?command=CommandName&parameters/arguments
where,
ip_adr = the IP address of the CR1000.
CommandName = the the API command.
parameters / arguments = the API command parameters and associated
arguments.
& is used when appending parameters and arguments to the command string.
Some commands have optional parameters wherein omitting a parameter results
in the use of a default argument. Some commands return a response code
indicating the result of the command. The following table lists API parameters
and arguments and the commands wherein they are used. Parameters and
arguments for specific commands are listed in the following sections.
Table 109. API Commands, Parameters, and Arguments
Parameter
uri
Commands in which the
parameter is used
x
BrowseSymbols
x
DataQuery
x
ClockSet
x
ClockCheck
x
ListFiles
Function of parameter
Specifies the data source.
Argument(s)
x
source: dl
(datalogger is data
source): default,
applies to all
commands listed in
column 2.
x
tablename.fieldnam
e: applies only to
BrowseSymbols,
and DataQuery
425
Section 8. Operation
Table 109. API Commands, Parameters, and Arguments
Parameter
format
mode
p1
Commands in which the
parameter is used
x
BrowseSymbols
x
DataQuery
x
ClockSet
x
ClockCheck
x
FileControl
x
ListFiles
DataQuery
DataQuery
Function of parameter
Specifies response format.
Specifies range of data with
which to respond.
x
html, xml, json:
apply to all
commands listed in
column 2.
x
toa5 and tob1 apply
only to DataQuery
x
most-recent
x
since-time
x
since-record
x
data-range
x
backfill
x
maximum number of
records (when using
most-recent
argument).
x
integer number of
records (when using
most-recent
argument)
x
beginning date and/or
time (when using
since-time ,or daterange arguments).
x
x
beginning record
number (when using
since-record
argument).
time in defined
format (when using
since-time ,or daterange arguments,
see Time Syntax (p.
427) section)
x
integer record
number(when using
since-record
argument).
x
integer number of
seconds (when using
backfill argument).
x
426
Argument(s)
interval in seconds
(when using backfill
argument).
p2
DataQuery
Specifies ending date and/or
time when using date-range
argument.
time expressed in defined
format (see Time Syntax (p.
427) section)
value
SetValueEx
Specifies the new value.
numeric or string
time
ClockSet
Specifies set time.
time in defined format
action
FileControl
Specifies FileControl action.
1 through 20
file
FileControl
Specifies first argument of
FileControl action.
file name with drive
file2
FileControl
Specifies second argument
parameter of FileControl
action.
file name with drive
Section 8. Operation
Table 109. API Commands, Parameters, and Arguments
Parameter
Commands in which the
parameter is used
NewestFile
expr
8.6.3.14.3
Function of parameter
Argument(s)
Specifies path and wildcard
expression for the desired set of
files to collect.
path and wildcard expression
Time Syntax
API commands may have a time stamp parameter. Consult the Clock Functions (p.
for more information. The format for the parameter is:
578) section
YYYY-MM-DDTHH:MM:SS.MS
where,
YYYY = four-digit year
MM = months into the year, one or two digits (1 to 12)
DD = days into the month, one or two digits (1 to 31)
HH = hours into the day, one or two digits (1 to 23)
MM = minutes into the hour, one or two digits (1 to 59)
SS = seconds into the minute, one or two digits (1 to 59)
MS = sub-second, optional when specifying time, up to nine digits (1 to
<1E9)
The time parameters 2010-07-27T12:00:00.00 and 2010-07-27T14:00:00 are
used in the following URL example:
http://192.168.4.14/?command=dataquery&uri=dl:WSN30sec.CWS900_Ts
&format=html&mode=date-range&p1=2010-07-27T12:00:00&p2=2010-0727T14:00:00
8.6.3.14.4
Data Management — BrowseSymbols Command
BrowseSymbols allows a web client to poll the host CR1000 for its data memory
structure. Memory structure is made up of table name(s), field name(s), and array
sub-scripts. These together constitute "symbols." BrowseSymbols takes the
form:
http://ip_address/?command=BrowseSymbols&uri=source:tablename.fi
eldname&format=html
BrowseSymbols requires a minimum .csipasswd access level of 3 (read-only).
Table 110. BrowseSymbols API Command Parameters
uri
Optional. Specifies the URI (p. 532) for the data source. When
querying a CR1000, uri source, tablename and fieldname are
optional. If source is not specified, dl (CR1000) is assumed. A
field name is always specified in association with a table name.
If the field name is not specified, all fields are output. If
fieldname refers to an array without a subscript, all fields
associated with that array will be output. Table name is
optional. If table name is not used, the entire URI syntax is not
needed.
format
Optional. Specifies the format of the response. The values
html, json, and xml are valid. If this parameter is omitted, or if
the value is html, empty, or invalid, the response is HTML.
427
Section 8. Operation
Examples:
Command for a response wherein symbols for all tables are returned as
HTML
http://192.168.24.106/?command=BrowseSymbols&uri=dl:public&fo
rmat=html
Command for a response wherein symbols for all fields in a single table
(MainData) are returned as HTML
http://192.168.24.106/?command=BrowseSymbols&uri=dl:MainData&
format=html
Command for a response wherein symbols for a single field (Cond41) are
returned as HTML
http://192.168.24.106/?command=BrowseSymbols&uri=dl:MainData.
Cond41&format=html
BrowseSymbols Response
The BrowseSymbols format parameter determines the format of the response. If
a format is not specified, the format defaults to HTML. For more detail
concerning data response formats, see the Data File Formats (p. 377) section.
The response consists of a set of child symbol descriptions. Each of these
descriptions include the following fields:
Table 111. BrowseSymbols API Command Response
name
Specifies the name of the symbol. This could be a data source
name, a station name, a table name, or a column name.
uri
Specifies the uri of the child symbol.
Specifies a code for the type of this symbol. The symbol types
include the following:
type
6 — Table
7 — Array
8 — Scalar
is_enabled
Boolean value that is set to true if the symbol is enabled for
scheduled collection. This applies mostly to LoggerNet data
sources.
is_read_only
Boolean value that is set to true if the symbol is considered to
be read-only. A value of false would indicate an expectation
that the symbol value can be changed using the SetValueEx
command.
can_expand
Boolean value that is set to true if the symbol has child values
that can be listed using the BrowseSymbols command.
If the client specifies the URI for a symbol that does not exist, the server will
respond with an empty symbols set.
HTML Response
When html is entered in the BrowseSymbols format parameter, the response will
be HTML. Following are example responses.
428
Section 8. Operation
HTML tabular response:
HTML page source:
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">
<html> <head>
<title>BrowseSymbols Response</title>
</head>
<body>
<h1>BrowseSymbols Response</h1>
<table border="1">
<tr>
<th>name</th><th>uri</th><th>type</th><th>is_enabled</th><th>is_
read_only</th><th>can_expand</th></tr><tr>
<td>Status</td><td>dl:Status</td><td>6</td><td>true</td><td>fals
e</td><td>true</td></tr><tr>
<td>MainData</td><td>dl:MainData</td><td>6</td><td>true</td><td>
false</td><td>true</td></tr><tr>
<td>BallastTank1</td><td>dl:BallastTank1</td><td>6</td><td>true<
/td><td>false</td><td>true</td></tr><tr>
<td>BallastTank2</td><td>dl:BallastTank2</td><td>6</td><td>true<
/td><td>false</td><td>true</td></tr><tr>
<td>BallastTank3</td><td>dl:BallastTank3</td><td>6</td><td>true<
/td><td>false</td><td>true</td></tr><tr>
<td>BallastTank4</td><td>dl:BallastTank4</td><td>6</td><td>true<
/td><td>false</td><td>true</td></tr><tr>
<td>BallastLine</td><td>dl:BallastLine</td><td>6</td><td>true</t
d><td>false</td><td>true</td></tr><tr>
<td>Public</td><td>dl:Public</td><td>6</td><td>true</td><td>fals
e</td><td>true</td></tr>
</table>
</body> </html>
XML Response
When xml is entered in the BrowseSymbols format parameter, the response will
be formated as CSIXML (p. 90) with a BrowseSymbolsResponse root element
name. Following is an example response.
429
Section 8. Operation
Example page source output:
<BrowseSymbolsResponse>
..<symbol
name="Status"
uri="dl:Status"
type="6"
is_enabled="true"
is_read_only="false"
can_expand="true"/><symbol
name="MainData"
uri="dl:MainData"
type="6"
is_enabled="true"
is_read_only="false"
can_expand="true"/><symbol
name="BallastTank1"
uri="dl:BallastTank1"
type="6"
is_enabled="true"
is_read_only="false"
can_expand="true"/><symbol
name="BallastTank2"
uri="dl:BallastTank2"
type="6"
is_enabled="true"
is_read_only="false"
can_expand="true"/><symbol
name="BallastTank3"
uri="dl:BallastTank3"
type="6"
is_enabled="true"
is_read_only="false"
can_expand="true"/><symbol
name="BallastTank4"
uri="dl:BallastTank4"
type="6"
is_enabled="true"
is_read_only="false"
can_expand="true"/><symbol
name="BallastLine"
uri="dl:BallastLine"
type="6"
is_enabled="true"
is_read_only="false"
can_expand="true"/><symbol
name="Public"
uri="dl:Public"
type="6"
is_enabled="true"
is_read_only="false"
can_expand="true"/>
</BrowseSymbolsResponse>
JSON Response
When json is entered in the BrowseSymbols format parameter, the response will
be formated as CSIJSON (p. 90). Following is an example response.
430
Section 8. Operation
{
"symbols": [
{"name": "Status","uri": "dl:Status","type": 6,"is_enabled":
true,"is_read_only": false,"can_expand": true},
{"name": "MainData","uri": "dl:MainData","type":
6,"is_enabled": true,"is_read_only": false,"can_expand": true},
{"name": "BallastTank1","uri": "dl:BallastTank1","type":
6,"is_enabled": true,"is_read_only": false,"can_expand": true},
{"name": "BallastTank2","uri": "dl:BallastTank2","type":
6,"is_enabled": true,"is_read_only": false,"can_expand": true},
{"name": "BallastTank3","uri": "dl:BallastTank3","type":
6,"is_enabled": true,"is_read_only": false,"can_expand": true},
{"name": "BallastTank4","uri": "dl:BallastTank4","type":
6,"is_enabled": true,"is_read_only": false,"can_expand": true},
{"name": "BallastLine","uri": "dl:BallastLine","type":
6,"is_enabled": true,"is_read_only": false,"can_expand": true},
{"name": "Public","uri": "dl:Public","type": 6,"is_enabled":
true,"is_read_only": false,"can_expand": true}
]
}
8.6.3.14.5
Data Management — DataQuery Command
DataQuery allows a web client to poll the CR1000 for data. DataQuery
typically takes the form:
http://ip_address/?command=DataQuery&uri=dl:tablename.fieldname&
format=_&mode=_&p1=_&p2=_
DataQuery requires a minimum .csipasswd access level of 3 (read-only).
Table 112. DataQuery API Command Parameters
uri
Optional. Specifies the URI (p. 532) for data to be queried. Syntax: dl:tablename.fieldname.
Field name is optional. Field name is always specified in association with a table name. If field
name is not specified, all fields are collected. If fieldname refers to an array without a subscript,
all values associated with that array will be output. Table name is optional. If table name is not
used, the entire URI syntax is not needed as dl (CR1000) is the default data source.
Required. Modes for temporal-range of collected-data:
most-recent returns data from the most recent number of records. p1 specifies maximum number
of records.
since-time returns most recent data since a certain time. p1 specifies the beginning time stamp
(see Time Syntax (p. 427) section).
mode
since-record returns records (p. 525) since a certain record number. The record number is specified
by p1. If the record number is not present in the table, the CR1000 will return all data starting
with the oldest record.
date-range returns data in a certain date range. The date range is specified using p1 and p2. Data
returned include data from date specified by p1 but not by p2 (half-open interval).
backfill returns data stored since a certain time interval (for instance, all the data since 1 hour
ago). The interval, in seconds, is specified using p1.
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Section 8. Operation
Optional. Specifies:
p1
x
maximum number of records (most-recent)
x
beginning date and/or time (since-time, date-range). See Time Syntax (p. 427) for
format.
x
beginning record number (since-record)
x
interval in seconds (backfill)
Optional. Specifies:
p2
x
ending date and/or time (date-range). See Time Syntax (p. 427) for format.
Optional. Specifies the format of the output. If this parameter is omitted, or if the value is html,
empty, or invalid, the output is HTML.
format
format Option
Data Output Format
Content-Type Field of
HTTP Response Header
html
HTML
text/html
xml
CSIXML
text/xml
json
CSIJSON
application/json
toa5
TOA5
text/csv
tob1
TOB1
binary/octet-stream
Note: When json is used, and the web server has a large data set to send, the web server may
choose to break the data into multiple requests by specifying a value of true for the more flag in
the CSIJSON output. The more flag is not shown if a complete data set is first returned.
Examples:
Command:
http://192.168.24.106/?command=DataQuery&uri=dl:MainData&mode=da
te-range&p1=2012-09-14T8:00:00&p2=2012-09-14T9:00:00
Response: collect all data from table MainData within the range of p1 to
p2
Command:
http://192.168.24.106/?command=DataQuery&uri=dl:MainData.Cond41&
format=html&mode=most-recent&p1=70
Response: collect the five most recent records from table MainData
Command:
http://192.168.24.106/?command=DataQuery&uri=dl:MainData.Cond41&
format=html&mode=since-time&p1=2012-09-14T8:00:00
Response: collect all records of field Cond41 since the specified date and
time
Command:
http://192.168.24.106/?command=DataQuery&uri=dl:MainData.Cond41&
format=html&mode=since-record&p1=4700
Response: collect all records since the specified record
432
Section 8. Operation
Command:
http://192.168.24.106/?command=DataQuery&uri=dl:MainData.Cond41&
format=html&mode=backfill&p1=7200
Response: backfill all records since 3600 seconds ago
DataQuery Response
The DataQuery format parameter determines the format of the response. For
more detail concerning data response formats, see the Data File Formats (p. 377)
section.
When html is entered in the DataQuery format parameter, the response will be
HTML. Following are example responses.
HTML Response
HTML tabular response:
HTML page source:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<HTML><HEAD><TITLE>Table Display</TITLE><meta httpequiv="Pragma" content="no-cache"><meta http-equiv="expires"
content="0">
</HEAD><BODY>
<h1>Table Name: BallastLine</h1>
<table border="1" cellpadding="2" cellspacing="0">
<tr valign="middle" align="center">
<th nowrap>TimeStamp</th>
<th nowrap>Record</th>
<th nowrap>Induced_Water</th>
</tr>
<tr valign="middle" align="center">
<td nowrap>2012-08-21 22:41:50.0</td>
<td nowrap>104</td>
<td nowrap>66</td>
</tr>
<tr valign="middle" align="center">
<td nowrap>2012-08-21 22:42:00.0</td>
<td nowrap>105</td>
<td nowrap>66</td>
</tr>
<tr valign="middle" align="center">
<td nowrap>2012-08-21 22:42:10.0</td>
<td nowrap>106</td>
<td nowrap>66</td>
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Section 8. Operation
</tr>
<tr valign="middle" align="center">
<td nowrap>2012-08-21 22:42:20.0</td>
<td nowrap>107</td>
<td nowrap>66</td>
</tr>
<tr valign="middle" align="center">
<td nowrap>2012-08-21 22:42:30.0</td>
<td nowrap>108</td>
<td nowrap>66</td>
</tr>
</table>
</BODY></HTML>
XML Response
When xml is entered in the DataQuery format parameter, the response will be
formatted as CSIXML. Following is an example response.
<?xml version="1.0" standalone="yes"?>
<csixml version="1.0">
<head>
<environment>
<station-name>Q2</station-name>
<table-name>BallastLine</table-name>
<model>CR1000</model>
<serial-no>18583</serial-no>
<os-version>CR1000.Std.25</os-version>
<dld-name>CPU:IndianaHarbor_081712.CR1</dld-name>
<dld-sig>33322</dld-sig>
</environment>
<fields>
<field name="Induced_Water" type="xsd:float" process="Smp"/>
</fields>
</head>
<data>
<r time="2012-08-21T22:41:50" no="104">
<v1>66</v1></r><r time="2012-08-21T22:42:00" no="105">
<v1>66</v1></r><r time="2012-08-21T22:42:10" no="106">
<v1>66</v1></r><r time="2012-08-21T22:42:20" no="107">
<v1>66</v1></r><r time="2012-08-21T22:42:30" no="108">
<v1>66</v1></r></data>
</csixml>
JSON Response
When json is entered in the DataQuery format parameter, the response will be
formatted as CSIJSON. Following is an example response:
{
.."head": {
...."transaction": 0,
...."signature": 26426,
...."environment": {
......"station_name": "Q2",
......"table_name": "BallastLine",
......"model": "CR1000",
......"serial_no": "18583",
......"os_version": "CR1000.Std.25",
......"prog_name": "CPU:IndianaHarbor_081712.CR1"
434
Section 8. Operation
....},
...."fields": [{
......"name": "Induced_Water",
......"type": "xsd:float",
......"process": "Smp",
......"settable": false}]
},
......"data": [{
......"time": "2012-08-21T22:41:50",
......"no": 104,
......"vals": [66]
},{
......"time": "2012-08-21T22:42:00",
......"no": 105,
......"vals": [66]
},{
......"time": "2012-08-21T22:42:10",
......"no": 106,
......"vals": [66]
},{
......"time": "2012-08-21T22:42:20",
......"no": 107,
......"vals": [66]
},{
......"time": "2012-08-21T22:42:30",
......"no": 108,
......"vals": [66]
}]}
TOA5 Response
When toa5 is entered in the DataQuery format parameter, the response will be
formated as Campbell Scientific TOA5. Following is an example response:
"TOA5","TXSoil","CR1000","No_SN","CR1000.Std.25","TexasRun_1b.CR
2","12645","_1Hr"
"TIMESTAMP","RECORD","ID","_6_inch","One","Two","Three","Temp_F_
Avg","Rain_in_Tot"
"TS","RN","","","","","","",""
"","","Smp","Smp","Smp","Smp","Smp","Avg","Tot"
"2012-05-03 17:00:00",0,0,-0.8949984,-0.95232,-0.8949984,0.8637322,2.144136,0.09999999
"2012-05-03 18:00:00",1,0,-0.9106316,-0.9731642,-0.9210536,0.8845763,72.56885,0
"2012-05-03 19:00:00",2,0,-0.9210536,-0.9679532,-0.9106316,0.8637322,72.297,0
"2012-05-03 20:00:00",3,0,-0.8624293,-0.9145398,-0.8624293,0.8311631,72.68445,0
"2012-05-03 21:00:00",4,0,-0.8949984,-0.9471089,-0.9002095,0.8585211,72.79237,0
"2012-05-03 22:00:00",5,0,-0.9262648,-0.9731642,-0.9158427,0.8793653,72.75194,0
"2012-05-03 23:00:00",6,0,-0.8103188,-0.8624293,-0.8103188,0.7686304,72.72644,0
"2012-05-04 00:00:00",7,0,-0.9158427,-0.9627421,-0.9158427,0.8689431,72.67271,0
"2012-05-04 01:00:00",8,0,-0.8598238,-0.9015122,-0.8598238,0.8129244,72.64571,0
"2012-05-04 02:00:00",9,0,-0.9158427,-0.9575311,-0.9054205,0.8689431,72.5931,0
435
Section 8. Operation
"2012-05-04 03:00:00",10,0,-0.8754569,-0.9275675,-0.8910902,0.8546127,72.53336,0
"2012-05-04 04:00:00",11,0,-0.8949984,-0.9575311,-0.9106316,0.8793653,72.47779,0
"2012-05-04 05:00:00",12,0,-0.9236593,-0.9705587,-0.908026,0.8715487,72.4006,0
"2012-05-04 06:00:00",13,0,-0.9184482,-0.9601365,-0.902815,0.8819707,72.23279,0
"2012-05-05 11:00:00",0,5,-0.9106316,-0.941898,-0.8897874,0.8637322,4.740396,0
"2012-05-05 12:00:00",1,5,-0.9067233,-0.9640449,-0.9015122,0.8702459,71.16611,0
"2012-05-05 13:00:00",2,5,-0.8897874,-0.9366869,-0.8793653,0.8428879,70.93591,0
"2012-05-05 14:00:00",3,5,-0.9041178,-0.9510173,-0.8884846,0.8676404,70.78558,0
"2012-05-05 15:00:00",4,5,-0.9002095,-0.9627421,-0.9002095,0.8689431,70.66192,0
"2012-05-05 16:00:00",5,5,-0.9054205,-0.95232,-0.9054205,0.8741542,70.53237,0
"2012-05-05 17:00:00",6,5,-0.9158427,-0.9731642,-0.9002095,0.8637322,70.4076,0
"2012-05-05 18:00:00",7,5,-0.9223565,-0.969256,-0.9015122,0.8910902,70.33669,0
"2012-05-05 19:00:00",8,5,-0.8923929,-0.9445034,-0.8923929,0.8507045,70.25033,0
"2012-05-05 20:00:00",9,5,-0.9119344,-0.9640449,-0.9171454,0.8754569,70.1702,0
"2012-05-05 21:00:00",10,5,-0.930173,-0.9822836,-0.9197509,0.8832736,70.1116,0
"2012-05-05 22:00:00",11,5,-0.9132372,-0.9653476,-0.908026,0.8611265,70.0032,0
"2012-05-05 23:00:00",12,5,-0.9353842,-0.9822836,-0.930173,0.8936957,69.83805,0
TOB1 Response
When tob1 is entered in the DataQuery format parameter, the response will be
formated as Campbell Scientific TOB1. Following is an example response.
Example:
"TOB1","11467","CR1000","11467","CR1000.Std.20","CPU
:file format.CR1","61449","Test"
"SECONDS","NANOSECONDS","RECORD","battfivoltfiMin","
PTemp"
"SECONDS","NANOSECONDS","RN","",""
"","","","Min","Smp"
"ULONG","ULONG","ULONG","FP2","FP2"
376
}Ÿp' E1HŒŸp' E1H›Ÿp' E1HªŸp' E1H¹Ÿp'
E1H
8.6.3.14.6
Control — SetValueEx Command
SetValueEx allows a web client to set a value in a host CR1000 CRBasic
variable.
http://ip_address/?command=SetValueEx&uri=dl:table.variable&valu
e=x.xx
436
Section 8. Operation
SetValueEx requires a minimum .csipasswd access level of 2 (set variables
allowed).
Table 113. SetValueEx API Command Parameters
Specifies the variable that should be set in the following format:
uri
dl:tablename.fieldname
value
Specifies the value to set
The following table lists optional output formats for SetValueEx result codes. If not specified,
result codes output as HTML.
format
Result Code Output
Option
Result Code Output
Format
Content-Type Field of
HTTP Response Header
html
HTML
text/html
json
CSIJSON
application/json
xml
CSIXML
text/xml
Example: &format=html
Specifies the format of the response. The values html, json, and xml are valid. If this parameter is
omitted, or if the value is html, empty, or invalid, the response is HTML.
Examples:
http://192.168.24.106/?command=SetValueEx&uri=dl:public.NaOH_Set
pt_Bal2&value=3.14
Response: the public variable settable_float is set to 3.14.
http://192.168.24.106/?command=SetValueEx&uri=dl:public.flag&val
ue=-1&format=html
Response: the public Boolean variable Flag(1) in is set to True (-1).
SetValueEx Response
The SetValueEx format parameter determines the format of the response. If a
format is not specified, the format defaults to HTML For more detail concerning
data response formats, see the Data File Formats (p. 377) section.
Responses contain two fields. In the XML output, the fields are attributes.
Table 114. SetValue API Command Response
0 — An unrecognized failure occurred
1 — Success
5 — Read only
6 — Invalid table name
outcome
7 — Invalid fieldname
8 — Invalid fieldname subscript
9 — Invalid field data type
10 — Datalogger communication failed
12 — Blocked by datalogger security
15 — Invalid web client authorization
description
A text description of the outcome code.
437
Section 8. Operation
HTML Response
When html is entered in the SetValueEx format parameter, the response will be
HTML Following are example responses.
HTML tabular response:
HTML page source:
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">
<html> <head>
<title>SetValueExResponse</title>
</head>
<body>
<h1>SetValueExResponse</h1>
<table border="1">
<tr>
<td>outcome</td>
<td>outcome-code</td>
</tr>
<tr>
<td>description</td>
<td>description-text</td>
</tr>
</table>
</body> </html>
XML Response
When xml is entered in the SetValueEx format parameter, the response will be
CSIXML with a SetValueExResponse root element name. Following is an
example response:
<SetValueExResponse outcome="outcome-code"
description="description-text"/>
JSON Response
When json is entered in the SetValueEx format parameter, the response will be
CSIJSON. Following is an example response:
{
"outcome": outcome-code,
"description": description
}
438
Section 8. Operation
8.6.3.14.7
Clock Functions — ClockSet Command
ClockSet allows a web client to set the CR1000 real time clock. ClockSet takes
the form:
http://ip_address/?command=ClockSet&format=html&time=YYYY-MMDDTHH:MM:SS.MS
ClockSet requires a minimum .csipasswd access level of 1 (all access allowed).
Table 115. ClockSet API Command Parameters
If this parameter is excluded, or if it is set to "datalogger"
(uri=dl) or an empty string (uri=), the command is sent to the
uri
1
CR1000 web server.
format
Specifies the format of the response. The values html, json, and
xml are valid. If this parameter is omitted, or if the value is
html, empty, or invalid, the response is HTML.
time
Specifies the time to which the CR1000 real-time clock is set.
This value must conform to the format described for input time
stamps in the Time Syntax (p. 427) section.
1
optionally specifies the URI for the LoggerNet source station to be set
Example:
http://192.168.24.106/?command=ClockSet&format=html&time=2012-914T15:30:00.000
Response: sets the host CR1000 real time clock to 3:30 PM 14
September 2012.
ClockSet Response
The ClockSet format parameter determines the format of the response. If a
format is not specified, the format defaults to HTML. For more detail concerning
data response formats, see the Data File Formats (p. 377) section.
Responses contain three fields as described in the following table:
Table 116. ClockSet API Command Response
1 — The clock was set
outcome
5 — Communication with the CR1000 failed
6 — Communication with the CR1000 is disabled
8 — An invalid URI was specified.
time
Specifies the value of the CR1000 clock before it was changed.
description
A string that describes the outcome code.
HTML Response
When html is entered in the ClockSet format parameter, the response will be
HTML. Following are example responses.
439
Section 8. Operation
HTML tabular response:
HTML page source:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN"><html>
<head><title>ClockSet Response</title></head>
<body>
<h1>ClockSet Response</h1>
<table border="1">
<tr><td>outcome</td><td>1</td>
</tr><td>time</td>
<td>2011-12-01 11:42:02.75</td>
</tr><tr><td>description</td><td>The clock was set</td></tr>
</table> </body> </html>
XML Response
When xml is entered in the ClockSet format parameter, the response will be
formated as CSIXML (p. 90) with a ClockSetResponse root element name.
Following is an example response.
<ClockSetResponse outcome="1" time="2011-12-01T11:41:21.17"
description="The clock was set"/>
JSON Response
When json is entered in the ClockSet format parameter, the response will be
formated as CSIJSON (p. 90). Following is an example response.
{"outcome": 1,"time": "2011-12-01T11:40:32.61","description": "
The clock was set"}
8.6.3.14.8
Clock Functions — ClockCheck Command
ClockCheck allows a web client to read the real-time clock from the host
CR1000. DataQuery takes the form:
http://ip_address/?command=ClockCheck&format=html
ClockCheck requires a minimum .csipasswd access level of 3 (read-only).
Table 117. ClockCheck API Command Parameters
uri
If this parameter is excluded, or if it is set to "datalogger"
(uri=dl) or an empty string (uri=), the host CR1000 real-time
1
clock is returned.
format
1
440
Specifies the format of the response. The values html, json, and
xml are recognized. If this parmeter is omitted, or if the value is
html, empty, or invalid, the response is HTML.
optionally specifies the URI for a LoggerNet source station to be checked
Section 8. Operation
Example:
http://192.168.24.106/?command=ClockCheck&format=html
Response: checks the host CR1000 real time clock and requests the
response be an HTML table.
ClockCheck Response
The ClockCheck format parameter determines the format of the response. If a
format is not specified, the format defaults to HTML. For more detail concerning
data response formats, see the Data File Formats (p. 377) section.
Responses contain three fields as described in the following table:
Table 118. ClockCheck API Command Response
Codes that specifies the outcome of the ClockCheck command.
Codes in grey text are not valid inputs for the CR1000:
1 — The clock was checked
1
2 — The clock was set
3 — The LoggerNet session failed
4 — Invalid LoggerNet logon
outcome
5 — Blocked by LoggerNet security
6 — Communication with the specified station failed
7 — Communication with the specified station is disabled
8 — Blocked by datalogger security
9 — Invalid LoggerNet station name
10 — The LoggerNet device is busy
11 — The URI specified does not reference a LoggerNet station.
2
time
Specifies the current value of the CR1000 real-time clock . This
value will only be valid if the value of outcome is set to 1. This
value will be formatted in the same way that record time stamps
are formatted for the DataQuery response.
description
A text string that describes the outcome.
1
LoggerNet may combine a new clock check transaction with pending LoggerNet clock set
transactions
2
or LoggerNet server
HTML Response
When html is entered in the ClockCheck format parameter, the response will be
HTML. Following are example responses.
HTML tabular response:
441
Section 8. Operation
HTML page source:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN"><html>
<head><title>ClockCheck Response</title></head>
<body>
<h1>ClockCheck Response</h1>
<table border="1">
<tr><td>outcome</td><td>1</td>
</tr><td>time</td>
<td>2012-08-24 15:44:43.59</td>
</tr><tr><td>description</td><td>The clock was checked</td></tr>
</table> </body> </html>
XML Response
When xml is entered in the ClockCheck format parameter, the response will be
formated as CSIXML (p. 90) with a ClockCheckResponse root element name.
Following is an example response.
<ClockCheckResponse outcome="1" time="2012-08-24T15:50:50.59"
description="The clock was checked"/>
JSON Response
When json is entered in the ClockCheck format parameter, the response will be
formated as CSIJSON (p. 90). Following is an example response.
Example:
{
"outcome": 1,
"time": "2012-08-24T15:52:26.22",
"description": " The clock was checked"
}
8.6.3.14.9
File Management — Sending a File to a Datalogger
A file can be sent to the CR1000 using an HTTPPut request. Sending a file
requires a minimum .csipasswd access level of 1 (all access allowed). Unlike
other web API commands, originating a PUT request from a browser address bar
is not possible. Instead, use JavaScript within a web page or use the program
Curl.exe. Curl.exe is available in the LoggerNet RTMC program files folder or at
http://curl.haxx.se. The Curl.exe command line takes the following form
(command line parameters are described in the accompanying table):
curl -XPUT -v -S -T "filename.ext" --user username:password
http://IPAdr/drive/
Table 119. Curl HTTPPut Request Parameters
Parameter
442
Description
-XPUT
Instructs Curl.exe to use the HTTPPut command
-v
Instructs Curl.exe to print all output to the screen
-S
Instructs Curl.exe to show errors
-T "filename.ext"
name of file to send to CR1000 (enclose in quotes)
username
user name in the .csipasswrd file
Section 8. Operation
password
password in the .csipasswrd file
IPAdr
IP address of the CR1000
drive
memory drive of the CR1000
Examples:
To load an operating system to the CR1000, open a command prompt window
("DOS window") and execute the following command, as a continuous line:
curl -XPUT -v -S -T
"c:\campbellsci\lib\OperatingSystems\CR1000.Std.25.obj" --user
harrisonford:lostark1 http://192.168.24.106/cpu/
Response:
* About to connect() to 192.168.7.126 port 80 (#0)
*
Trying 192.168.7.126... connected
* Connected to 192.168.7.126 (192.168.7.126) port 80 (#0)
* Server auth using Basic with user 'fredtest'
>PUT /cpu/myron%22Ecr1 HTTP/1.1
>Authorization: Basic ZGF2ZW1lZWs6d29vZnk5NTU1
>User-Agent: curl/7.21.1 (i386-pc-win32) libcurl/7.21.1
OpenSSL/0.9.8o zlib/1.2.5 libidn/1.18 libssh2/1.2.6
>Host: 192.168.7.126
>Accept:*/*
>Content-Length: 301
>Expect: 100-continue
>
*Done waiting for 100-continue
<HTTP/1.1 200 OK
<Date: Fri, 2 Dec 2011 05:31:50
<Server: CR1000.Std.25
<Content-Length: 0
<
* Connection #0 to host 192.168.7.126 left intact
* Closing connection #0
When a file with extension .OBJ is uploaded to the CR1000 CPU: drive, the
CR1000 sees the file as a new operating system (OS) and does not actually upload
it to CPU:. Rather, it captures it. When capture is complete, the CR1000 reboots
and compiles the new OS in the same manner as if it was sent via a datalogger
support software (p. 95) Connect screen.
Other files sent to a CR1000 drive work just as they would in datalogger support
software (p. 95) File Control. The exception is that CRBasic program run settings
cannot be set. To get a program file to run, use the web API FileControl
command. Curl.exe can be used to perform both operations, as the following
demonstrates:
Upload the program to the CR1000 CPU: drive (must have /cpu/ on end of the
URL):
curl -XPUT -v -S -T "program.CR1" --user username:password
"http://192.168.24.106/cpu/"
Compile and run the program and mark it as the program to be run on power up. XGET is not needed as it is the default command for Curl.exe.
443
Section 8. Operation
curl -v -S --user username:password
"http://192.168.24.106/?command=FileControl&file=CPU:program.CR1
&action=1"
Both operations can be combined in a batch file.
8.6.3.14.10 File Management — FileControl Command
FileControl allows a web client to perform file system operations on a host
CR1000. FileControl takes the form:
http://ip_address/?command=FileControl&file=drive:filename.dat&a
ction=x
FileControl requires a minimum .csipasswd access level of 1 (all access
allowed).
Table 120. FileControl API Command Parameters
1 — Compile and run the file specified by file and mark it as the program to be run on power up.
2 — Mark the file specified by file as the program to be run on power up.
3 — Mark the file specified by file as hidden.
4 — Delete the file specified by file.
5 — Format the device specified by file.
6 — Compile and run the file specified by file without deleting existing data tables.
7 — Stop the currently running program.
8 — Stop the currently running program and delete associated data tables.
9 — Perform a full memory reset.
10 — Compile and run the program specified by file but do not change the program currently
marked to run on power up.
11 — Pause execution of the currently running program.
12 — Resume execution of the currently paused program.
action
13 — Stop the currently running program, delete its associated data tables, run the program
specified by file, and mark the same file as the program to be run on power up.
14 — Stop the currently running program, delete its associated data tables, and run the program
specified by file without affecting the program to be run on power up.
15 — Move the file specified by file2 to the name specified by file.
16 — Move the file specified by file2 to the name specified by file, stop the currently running
program, delete its associated data tables, and run the program specified by file2 while marking it
to run on power up.
17 — Move the file specified by file2 to the name specified by file, stop the currently running
program, delete its associated data tables, and run the program specified by file2 without affecting
the program that will run on power up.
18 — Copy the file specified by file2 to the name specified by file.
19 — Copy the file specified by file2 to the name specified by file, stop the currently running
program, delete its associated data tables, and run the program specified by file2 while marking it
to run on power up.
20 — Copy the file specified by file2 to the name specified by file, stop the currently running
program, delete its associated data tables, and run the program specified by file2 without affecting
the program that will run on power up.
444
file
Specifies the first parameter for the file control operation. This parameter must be specified for
action values 1, 2, 3, 4, 5, 6, 10, 13, 14, 15, 16, 17, 18, 19, and 20.
file2
Specifies the second parameter for the file control operation. This parameter must be specified for
action values 15, 16, 17, 18, 19, and 20.
format
Specifies the format of the response. The values html, json, and xml are recognized. If this
parameter is omitted, or if the value is html, empty, or invalid, the response is HTML.
Section 8. Operation
Example:
http://192.168.24.106/?command=FileControl&file=USR:APITest.dat&
action=4
Response: APITest.dat is deleted from the CR1000 USR: drive.
http://192.168.24.106/?command=FileControl&file=CPU:IndianaJones
_090712_2.CR1&action=1
Response: Set program file to Run Now.
http://192.168.24.106/?command=FileControl&file=USR:FileCopy.dat
&file2=USR:FileName.dat&action=18
Response: Copy from file2 to file.
FileControl Response
All output formats contain the following parameters. Any action (for example, 9)
that performs a reset, the response is returned before the effects of the command
are complete.
Table 121. FileControl API Command Response
outcome
A response of zero indicates success. Non-zero indicates failure.
holdoff
Specifies the number of seconds that the web client should wait
before attempting more communication with the station. A value
of zero will indicate that communication can resume
immediately. This parameter is needed because many of the
commands will cause the CR1000 to perform a reset. In the case
of sending an operating system, it can take tens of seconds for
the datalogger to copy the image from memory into flash and to
perform the checking required for loading a new operating
system. While this reset is under way, the CR1000 will be
unresponsive.
description
Detail concerning the outcome code.
Example:
192.168.24.106/?command=FileControl&action=4&file=cpu:davetest.c
r1
Response: delete the file davetest.cr1 from the host CR1000 CPU: drive.
When html is entered in the FileControl format parameter, the response will be
HTML. Following is an example response.
8.6.3.14.11 File Management — ListFiles Command
ListFiles allows a web client to obtain a listing of directories and files in the host
CR1000. ListFiles takes the form:
http://ip_address/drive/?command=ListFiles
445
Section 8. Operation
ListFiles requires a minimum .csipasswd access level of 3 (read only).
Table 122. ListFiles API Command Parameters
Specifies the format of the response. The values html, json, and
xml are valid. If this parameter is omitted, or if the value is
html, empty, or invalid, the response is HTML.
format
If this parameter is excluded, or if it is set to "datalogger"
(uri=dl) or an empty string (uri=), the file system will be sent
uri
1
from the host CR1000.
1
Optionally specifies the URI to a LoggerNet datalogger station from which the file list will be
retrieved.
Examples:
http://192.168.24.106/?command=ListFiles
Response: returns the drive structure of the host CR1000 (CPU:, USR:,
CRD:, and USB:).
http://192.168.24.106/CPU/?command=ListFiles
Response: lists the files on the host CR1000 CPU: drive.
ListFiles Response
The format of the response depends on the value of the format parameter in the
command request. The response provides information for each of the files or
directories that can be reached through the CR1000 web server. The information
for each file includes the following:
Table 123. ListFiles API Command Response
path
Specifies the path to the file relative to the URL path.
is_dir
A boolean value that will identify that the object is a directory if
set to true.
size
An integer that gives the size of for a file in bytes (the value of
is_dir is false) or the bytes free for a directory.
last_write
A string associated only with files that specifies the date and
time that the file was last written.
run_now
A boolean attribute applied by the CR1000 for program files
that are marked as currently executing.
run_on_power_up
A boolean attribute applied by the CR1000 for program files
that are marked to run when the CR1000 powers up or resets.
read_only
A boolean attribute applied by the CR1000 for a file that is
marked as read-only.
paused
A boolean attribute applied by the CR1000 that is marked to run
but the program is now paused.
HTML Response
When html is entered in the ListFiles format parameter, the response will be
HTML. Following are example responses.
446
Section 8. Operation
HTML tabular response:
HTML page source:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"
"http://www.w3.org/TR/html4/loose.dtd">
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN"><html>
<head><title>ListFiles Response</title></head>
<body><h1>ListFiles Response</h1><table border="1">
<tr><td><b>Path</b></td>
<td><b>Is Directory</b></td>
<td><b>Size</b></td>
<td><b>Last Write</b></td>
<td><b>Run Now</b></td>
<td><b>Run On Power Up</b></td>
<td><b>Read Only</b></td>
<td><b>Paused</b></td></tr><tr>
<td>CPU/</td>
<td>true</td>
<td>443904</td>
<td>2012-06-22T00:00:00</td>
<td>false</td>
<td>false</td>
<td>false</td>
<td>false</td></tr><tr>
<td>CPU/ModbusMasterTCPExample.CR1</td>
<td>false</td>
<td>967</td>
<td>2012-07-10T18:21:44</td>
<td>false</td>
<td>false</td>
<td>false</td>
<td>false</td></tr><tr>
<td>CPU/CS475-Test.CR1</td>
<td>false</td>
<td>828</td><td>2012-07-16T14:16:50</td>
<td>false</td>
<td>false</td>
<td>false</td>
<td>false</td></tr><tr>
<td>CPU/DoubleModbusSlaveTCP.CR1</td>
<td>false</td>
<td>1174</td>
<td>2012-07-31T17:18:00</td>
<td>false</td>
<td>false</td>
<td>false</td>
<td>false</td></tr><tr>
447
Section 8. Operation
<td>CPU/untitled.CR1</td>
<td>false</td>
<td>1097</td>
<td>2012-08-07T10:48:20</td>
<td>false</td>
<td>false</td>
<td>false</td>
<td>false</td></tr><tr>
</table>
Page source template:
<!DOCTYPE HTML PUBLIC "-//IETF//DTD HTML//EN">
<html> <head>
<title>ListFiles Response</title>
</head>
<body>
<h1>ListFiles Response</h1>
<table border="1">
<tr>
<td><b>Path</b></td>
<td><b>Is Directory</b></td>
<td><b>Size</b></td>
<td><b>Last Write</b></td>
<td><b>Run Now</b></td>
<td><b>Run On Power Up</b></td>
<td><b>Read Only</b></td>
<td><b>Paused</b></td>
</tr>
<tr>
<td>CPU:</td>
<td>true</td>
<td>50000</td>
<td>YYYY-mm-dd hh:mm:ss.xxx</td>
<td>false</td>
<td>false</td>
<td>false</td>
<td>false</td>
</tr>
<tr>
<td>CPU:lights-web.cr1</td>
<td>false</td>
<td>16994</td>
<td>YYYY-mm-dd hh:mm:ss.xxx</td>
<td>true</td>
<td>true</td>
<td>false</td>
<td>false</td>
</tr>
</table>
XML Response
When xml is entered in the ListFiles format parameter, the response will be
formated as CSIXML (p. 90) with a ListFilesResponse root element name.
Following is an example response.
<ListFilesResponse>
<file
is_dir="true"
448
Section 8. Operation
path="CPU:"
size="50000"
last_write="yyyy-mm-ddThh:mm:ss.xxx"
run_now="false"
run_on_power_up="false"
read_only="false"
paused="false" />
<file
is_dir="false"
path="CPU:lights-web.cr1"
last_write="yyyy-mm-ddThh:mm:ss.xxx"
size="16994"
run_now="true"
run_on_power_up="true"
read_only="false"
paused="false"/>
</ListFilesResponse>
JSON Response
When json is entered in the ListFiles format parameter, the response will be
formated as CSIJSON (p. 90). Following is an example response.
{
"files": [
{
"path": "CPU:",
"is_dir": true,
"size": 50000,
"last_write": "yyyy-mm-ddThh:mm:ss.xxx",
"run_now": false,
"run_on_power_up": false,
"read_only": false,
"paused": false
},
{
"path": "CPU:lights-web.cr1",
"is_dir": false,
"size": 16994,
"last_write": "yyyy-mm-ddThh:mm:ss.xxx",
"run_now": true,
"run_on_power_up": true,
"read_only": false,
"paused": false
},
]
}
8.6.3.14.12 File Management — NewestFile Command
NewestFile allows a web client to request a file, such as a program or image, from
the host CR1000. If a wildcard (*) is included in the expression, the most recent
in a set of files whose names match the expression is returned. For instance, a
web page may be designed to show the newest image taken by a camera attached
to the CR1000. NewestFile takes the form:
http://192.168.13.154/?command=NewestFile&expr=drive:filename.ex
t
Where filename can be a wildcard (*).
449
Section 8. Operation
NewestFile requires a minimum .csipasswd access level of 3 (read only) for all
files except program files. Program files require access level 1 (all access
allowed).
Table 124. NewestFile API Command Parameters
Specifies the complete path and wildcard expression for the
1
expr
desired set of files . expr=USR:*.jpg selects the newest of the
collection of files on the USR: drive that have a .jpg extension.
1
The PC based web server will restrict the paths on the host computer to those that are allowed in
the applicable site configuration file (.sources.xml). This is done to prevent web access to all file
systems accessible to the host computer.
Example:
http://192.168.24.106/?command=NewestFile&expr=USR:*.jpg
Response: the web server collects the newest JPG file on the USR: drive
of the host CR1000
Note to retrieve any file, regardless of age, the url is
http://ip_address/drive/filename.ext. The name of the desired file is determined
using the ListFiles command.
NewestFile Response
The web server will transmit the contents of the newest file that matches the
expression given in expr. If there are no matching files, the server responds with a
404 Not Found HTTP response code.
8.7
Datalogger Support Software — Details
Reading List:
‡Datalogger Support Software — Quickstart (p. 46)
‡Datalogger Support Software — Overview (p. 95)
‡Datalogger Support Software — Details (p. 450)
‡Datalogger Support Software — Lists (p. 654)
Datalogger support software facilitates program generation, editing, data retrieval,
and real-time data monitoring.
x
x
x
450
PC200W Starter Software is available at no charge at
www.campbellsci.com/downloads (http://www.campbellsci.com/downloads).
It supports a transparent RS-232 connection between PC and CR1000, and
includes Short Cut for creating CR1000 programs. Tools for setting the
datalogger clock, sending programs, monitoring sensors, and on-site viewing
and collection of data are also included.
LoggerLink Mobile Apps are simple yet powerful tools that allow an iOS or
Android device to communicate with IP-enabled CR1000s. The apps support
field maintenance tasks such as viewing and collecting data, setting the clock,
and downloading programs.
PC400 Datalogger Support Software supports a variety of telecommunication
options, manual data collection, and data monitoring displays. Short Cut and
CRBasic Editor are included for creating CR1000 programs. PC400 does not
support complex communication options, such as phone-to-RF, PakBus®
Section 8. Operation
x
x
x
routing, or scheduled data collection.
LoggerNet Datalogger Support Software supports combined
telecommunication options, customized data-monitoring displays, and
scheduled data collection. It includes Short Cut and CRBasic Editor for
creating CR1000 programs. It also includes tools for configuring, troubleshooting, and managing datalogger networks. LoggerNet Admin and
LoggerNet Remote are available for more demanding applications.
LNLINUX Linux-based LoggerNet Server with LoggerNet Remote provides a
solution for those who want to run the LoggerNet server in a Linux
environment. The package includes a Linux version of the LoggerNet server
and a Windows version of LoggerNet Remote. The Windows-based client
applications in LoggerNet Remote are run on a separate computer, and are
used to manage the LoggerNet Linux server.
VISUALWEATHER Weather Station Software supports Campbell Scientific
weather stations. Version 3.0 or higher supports custom weather stations or
the ET107, ET106, and MetData1 pre-configured weather stations. The
software allows you to initialize the setup, interrogate the station, display
data, and generate reports from one or more weather stations.
Note More information about software available from Campbell Scientific can be
found at www.campbellsci.com http://www.campbellsci.com. Please consult with
a Campbell Scientific application engineer for a software recommendation to fit a
specific application.
8.8
Keyboard Display — Details
Related Topics:
‡Keyboard Display — Overview (p. 83)
‡ Keyboard Display — Details (p. 451)
‡Keyboard Display — List (p. 651)
‡Custom Menus — Overview (p. 84, p. 581)
Read More See Custom Menus (p. 182).
A keyboard is available for use with the CR1000. See appendix Keyboard
Displays (p. 651) for information on available keyboard displays. This section
illustrates the use of the keyboard display using default menus. Some keys have
special functions as outlined below.
Note Although the keyboard display is not required to operate the CR1000, it is a
useful diagnostic and debugging tool.
Table 125. Special Keyboard-Display Key Functions
Key
Special Function
[2] and [8]
Navigate up and down through the menu list one line at a time
[Enter]
Selects the line or toggles the option of the line the cursor is on
[Esc]
Back up one level in the menu
[Home]
Move cursor to top of the list
451
Section 8. Operation
Table 125. Special Keyboard-Display Key Functions
Key
[End]
Move cursor to bottom of the list
[Pg Up]
Move cursor up one screen
[Pg Dn]
Move cursor down one screen
[BkSpc]
Delete character to the left
[Shift]
[Num Lock]
Change alpha character selected
Change to numeric entry
[Del]
Delete
[Ins]
Insert/change graph setup
[Graph]
452
Special Function
Graph
Section 8. Operation
Figure 115.
Using the Keyboard / Display
453
Section 8. Operation
8.8.1
Data Display
Figure 116.
454
Displaying Data with the Keyboard / Display
Section 8. Operation
8.8.1.1 Real-Time Tables and Graphs
Figure 117.
Real-Time Tables and Graphs
8.8.1.2 Real-Time Custom
The CR1000KD Keyboard Display can be configured with a customized real-time
display. The CR1000 will keep the setup as long as the defining program is
running.
Read More Custom menus can also be programmed. See Custom Menus (p. 182)
for more information.
455
Section 8. Operation
Figure 118.
456
Real-Time Custom
Section 8. Operation
8.8.1.3 Final-Memory Tables
Figure 119.
Final-Memory Tables
457
Section 8. Operation
8.8.2
Run/Stop Program
Figure 120.
458
Run/Stop Program
Section 8. Operation
8.8.3
File Display
Figure 121.
File Display
8.8.3.1 File: Edit
The CRBasic Editor is recommended for writing and editing datalogger programs.
When making minor changes with the CR1000KD Keyboard Display, restart the
program to activate the changes, but be aware that, unless programmed for
otherwise, all variables, etc. will be reset. Remember that the only copy of
changes is in the CR1000 until the program is retrieved using datalogger support
software or removable memory.
459
Section 8. Operation
Figure 122.
460
File: Edit
Section 8. Operation
8.8.4
PCCard (Memory Card) Display
Figure 123.
PCCard (CF Card) Display
461
Section 8. Operation
8.8.5
Ports and Status
Read More See the appendix Registers.
8.8.6
462
Figure 124.
C Terminals (Ports) Status
Figure 125.
Settings
Settings
Section 8. Operation
8.8.6.1 Set Time / Date
Move the cursor to time element and press Enter to change it. Then move the
cursor to Set and press Enter to apply the change.
8.8.6.2 PakBus Settings
In the Settings menu, move the cursor to the PakBus® element and press Enter
to change it. After modifying, press Enter to apply the change.
8.8.7
Configure Display
Figure 126.
8.9
Configure Display
Program and OS File Compression Q and A
Q: What is Gzip?
A: Gzip is the GNU zip archive file format. This file format and the algorithms
used to create it are open source and free to use for any purpose. Files with the .gz
extension have been passed through these data compression algorithms to make
them smaller. For more information, go to www.gnu.org.
Q: Is there a difference between Gzip and zip?
A: While similar, Gzip and zip use different file compression formats and
algorithms. Only program files and OSs compressed with Gzip are compatible
with the CR1000.
Q: Why compress a program or operating system before sending it to a CR1000
datalogger?
463
Section 8. Operation
A: Compressing a file has the potential of significantly reducing its size. Actual
reduction depends primarily on the number and proximity of redundant blocks of
information in the file. A reduction in file size means fewer bytes are transferred
when sending a file to a datalogger. Compression can reduce transfer times
significantly over slow or high-latency links, and can reduce line charges when
using pay-by-the-byte data plans. Compression is of particular benefit when
transmitting programs or OSs over low-baud rate terrestrial radio, satellite, or
restricted cellular-data plans.
Q: Does my CR1000 support Gzip?
A: Version 25 of the standard CR1000 operating system supports receipt of Gzip
compressed program files and OSs.
Q: How do I Gzip a program or operating system?
A: Many utilities are available for the creation of a Gzip file. This document
specifically addresses the use of 7-Zip File Manager. 7-Zip is a free, open source,
software utility compatible with Windows®. Download and installation
instructions are available at http://www.7-zip.org/. Once 7-Zip is installed,
creating a Gzip file is as four-step process:
a) Open 7-Zip.
b) Drag and drop the program or operating system you wish to compress onto the
open window.
c) When prompted, set the archive format to “Gzip”.
464
Section 8. Operation
c) When prompted, set the archive format to “Gzip”.
d) Select OK.
The resultant file names will be of the type “myProgram.cr1.gz” and
“CR1000.Std.25.obj.gz”. Note that the file names end with “.gz”. The ".gz”
extension must be preceded with the original file extension (.cr1, .obj) as shown.
Q: How do I send a compressed file to the CR1000?
A: A Gzip compressed file can be sent to a CR1000 datalogger by clicking the
Send Program command in the datalogger support software (p. 95). Compressed
programs can also be sent using HTTP PUT to the CR1000 web server. The
CR1000 will not automatically decompress and use compressed files sent with
File Control, FTP, or a low-level OS download; however, these files can be
manually decompressed by marking as Run Now using File Control,
FileManage(), and HTTP.
Note Compression has little effect on an encrypted program (see FileEncrypt()
in the CRBasic Editor Help), since the encryption process does not produce a
large number of repeatable byte patterns. Gzip has little effect on files that
already employ compression such as JPEG or MPEG-4.
Table 126. Typical Gzip File Compression Results
File
Original Size Bytes
Compressed Size Bytes
1,753,976
671,626
Small program
2,600
1,113
Large program
32,157
7,085
CR1000 operating system
465
Section 8. Operation
8.10
Memory Cards and Record Numbers
Related Topics:
‡Memory Card (CRD: Drive) — Overview (p. 89)
‡Memory Card (CRD: Drive) — Details (p. 376)
‡Memory Cards and Record Numbers (p. 466)
‡Data Output: Writing High-Frequency Data to Memory Cards (p. 205)
‡File-System Errors (p. 389)
‡Data Storage Devices — List (p. 653)
‡Data-File Format Examples (p. 379)
‡Data Storage Drives Table (p. 373)
The number of records in a data table when CardOut() or TableFile() with
Option 64 is used in a data-table declaration is governed by these rules:
1. Memory cards (CRD: drive) and internal memory (CPU) keep copies of data
tables in binary TOB3 format. Collectible numbers of records for both CRD:
and CPU are reported in DataRecordSize entries in the Status table.
2. In the table definitions advertised to datalogger support software (p. 95), the
CR1000 advertises the greater of the number of records recorded in the Status
table, if the tables are not fill-and-stop.
3. If either data area is flagged for fill-and-stop, then whichever area stops first
causes all final-data storage to stop, even if there is more space allocated in the
non-stopped area, and so limiting the number of records to the minimum of the
two areas if both are set for fill-and-stop.
4. When CardOut() or TableFile() with Option 64 is present, whether or not a
card is installed, the CPU data-table space is allocated a minimum of about 5
KB so that there is at least a minimum buffer space for storing the data to
CRD: (which occurs in the background when the CR1000 has a chance to
copy data onto the card). So, for example, a data table consisting of one fourbyte sample, not interval driven, 20 bytes per record, including the 16 byte
TOB3 header/footer, 258 records are allocated for the internal memory for any
program that specifies less than 258 records (again only in the case that
CardOut() or TableFile() with Option 64 is present). Programs that specify
more than 258 records report what the user specified with no minimum.
5. When CardOut() or TableFile() with Option 64 is used but the card is not
present, zero bytes are reported in the Status table.
6. In both the internal memory and memory card data-table spaces, about 2 KB of
extra space is allocated (about 100 extra records in the above example) so that
for the ring memory the possibility is minimized that new data will overwrite
the oldest data when datalogger support software (p. 95) tries to collect the
oldest data at the same time. These extra records are not reported in the
Status table and are not reported to the datalogger support software and
therefore cannot be collected.
7. If the CardOut() or TableFile() with Option 64 instruction is set for fill-andstop, all the space reserved for records on the card is recorded before the
writing of final-data to memory stops, including the extra 2 kB allocated to
alleviate the conflict of storing the newest data while reading the oldest when
the area is not fill-and-stop, or is ringing around. Therefore, if the CPU does
466
Section 8. Operation
not stop earlier, or is ring and not fill-and-stop, then more records will be
stored on the card than originally allocated, i.e., about 2 KB worth of records,
assuming no lapses. At the point the writing of final-data stops, the CR1000
recalculates the number of records, displays them in the Status table, and
advertises a new table definition to the datalogger support software. Further,
if the table is storing relatively fast, there might be some additional records
already stored in the CPU buffer before final-data storage stops altogether,
resulting in a few more records than advertised able to be collected. For
example — on a CR1000 storing a four-byte value at a 10 ms rate, the CPU
not set to fill-and-stop, CRD: set to fill-and-stop after 500 records — after
final-data storage stopped, CRD: had 603 records advertised in the Status
table (an extra 103 due to the extra 2 KB allocated for ring buffering), but 608
records could be collected since it took 50 ms, or 5 records, to stop the CPU
from storing its 5 records beyond when the card was stopped.
8. Note that only the CRD: drive will keep storing until all its records are filled;
the CPU: drive will stop when the programmed number of records are stored.
9. Note that the O command in the terminal mode helps to visualize more
precisely what CPU: drive and the CRD: drive are doing, actual size allocated,
where they are at the present, etc.
8.11
Security — Details
Related Topics:
‡Security — Overview (p. 92)
‡Security — Details (p. 467)
The CR1000 is supplied void of active security measures. By default, RS-232,
Telnet, FTP and HTTP services, all of which give high level access to CR1000
data and CRBasic programs, are enabled without password protection.
You may wish to secure your CR1000 from mistakes or tampering. The
following may be reasons to concern yourself with datalogger security:
x
x
x
Collection of sensitive data
Operation of critical systems
Networks accessible by many individuals
If you are concerned about security, especially TCP/IP threats, you should send
the latest operating system (p. 86) to the CR1000, disable un-used services, and
secure those that are used. Security actions to take may include the following:
x
x
x
x
x
x
x
x
x
Set passcode lockouts
Set PakBus/TCP password
Set FTP username and password
Set AES-128 PakBus encryption key
Set .csipasswd file for securing HTTP and web API
Track signatures
Encrypt program files if they contain sensitive information
Hide program files for extra protection
Secure the physical CR1000 and power supply under lock and key
Note All security features can be subverted through physical access to the
CR1000. If absolute security is a requirement, the physical CR1000 must be kept
in a secure location.
467
Section 8. Operation
8.11.1 Vulnerabilities
While "security through obscurity" may have provided sufficient protection in the
past, Campbell Scientific dataloggers increasingly are deployed in sensitive
applications. Devising measures to counter malicious attacks, or innocent
tinkering, requires an understanding of where systems can be compromised and
how to counter the potential threat.
Note Older CR1000 operating systems are more vulnerable to attack than recent
updates. Updates can be obtained free of charge at www.campbellsci.com.
The following bullet points outline vulnerabilities:
x
CR1000KD Keyboard Display
o
o
o
x
LoggerNet
o
o
x
o
o
o
Send and change datalogger programs.
Send data that have been written to a file.
HTTP
o
o
o
o
468
Watch IP traffic in detail. IP traffic can reveal potentially sensitive
information such as FTP login usernames and passwords, and server
connection details including IP addresses and port numbers.
Watch serial traffic with other dataloggers and devices. A Modbus
capable power meter is an example.
View data in the Public and Status tables.
View the datalogger program, which may contain sensitive intellectual
property, security codes, usernames, passwords, connection information,
and detailed or revealing code comments.
FTP
o
o
x
All datalogger functions and data are easily accessed via RS-232 and
Ethernet using Campbell Scientific datalogger support software.
Cora command find-logger-security-code
Telnet
o
x
Pressing and holding the Del key while powering up a CR1000 will
cause it to abort loading a program and provides a 120 second window to
begin changing or disabling security codes in the settings editor (not
Status table) with the keyboard display.
Keyboard display security bypass does not allow telecommunication
access without first correcting the security code.
Note These features are not operable in CR1000KDs with serial
numbers less than 1263. Contact Campbell Scientific for information on
upgrading the CR1000KD operating system.
Send datalogger programs.
View table data.
Get historical records or other files present on the datalogger drive
spaces.
More access is given when a .csipasswd is in place, so ensure that users
with administrative rights have strong log-in credentials.
Section 8. Operation
8.11.2 Pass-Code Lockout
Pass-code lockouts (historically known in Campbell Scientific dataloggers simply
as "security codes") are the oldest method of securing a datalogger. Pass-code
lockouts can effectively lock out innocent tinkering and discourage wannabe
hackers on non-IP based telecommunication links. However, any serious hacker
with physical access to the datalogger or to the telecommunication hardware can,
with only minimal trouble, overcome the five-digit pass-codes. Systems
adequately secured with pass-code lockouts are probably limited to,
x
x
x
x
x
private, non-IP radio networks
direct links (hardwire RS-232, short-haul, multidrop, fiber optic)
non-IP satellite
land-line, non-IP based telephone, where the telephone number is not
published
cellular phone wherein IP has been disabled, providing a strictly serial
connection
Up to three levels of lockout can be set. Valid pass codes are 1 through 65535 (0
confers no security).
Note Although a pass code can be set to a negative value, a positive code must be
entered to unlock the CR1000. That positive code will equal 65536 + (negative
security code). For example, a security code of -1111 must be entered as 64425 to
unlock the CR1000.
Methods of enabling pass-code lockout security include the following:
x
x
x
x
Status table – Security(1), Security(2) and Security(3) registers are writable
variables in the Status table wherein the pass codes for security levels 1
through 3 are written, respectively.
CR1000KD Keyboard Display settings
Device Configuration Utility (DevConfig) – Security passwords 1 through 3
are set on the Deployment tab.
SetSecurity() instruction – SetSecurity() is only executed at program
compile time. It may be placed between the BeginProg and Scan()
instructions.
Note Deleting SetSecurity() from a CRBasic program is not equivalent to
SetSecurity(0,0,0). Settings persist when a new program is downloaded that has
no SetSecurity() instruction.
Level 1 must be set before Level 2. Level 2 must be set before Level 3. If a level
is set to 0, any level greater than it will be set to 0. For example, if level 2 is 0
then level 3 is automatically set to 0. Levels are unlocked in reverse order: level 3
before level 2, level 2 before level 1. When a level is unlocked, any level greater
than it will also be unlocked, so unlocking level 1 (entering the Level 1 security
code) also unlocks levels 2 and 3.
Functions affected by each level of security are:
x
Level 1 — Collecting data, setting the clock, and setting variables in the
Public table are unrestricted, requiring no security code. If Security1 code is
entered, read/write values in the Status table can be changed, and the
datalogger program can be changed or retrieved.
469
Section 8. Operation
x
x
Level 2 — Data collection is unrestricted, requiring no security code. If the
user enters the Security2 code, the datalogger clock can be changed and
variables in the Public table can be changed.
Level 3 — When this level is set, all communication with the datalogger is
prohibited if no security code is entered. If Security3 code is entered, data
can be viewed and collected from the datalogger (except data suppressed by
the TableHide() instruction in the CRBasic program). If Security2 code is
entered, data can be collected, public variables can be set, and the clock can
be set. If Security1 code is entered, all functions are unrestricted.
8.11.2.1 Pass-Code Lockout By-Pass
Pass-code lockouts can be bypassed at the datalogger using a CR1000KD
Keyboard Displaykeyboard display. Pressing and holding the Del key while
powering up a CR1000 will cause it to abort loading a program and provide a 120
second window to begin changing or disabling security codes in the settings editor
(not Status table) with the keyboard display.
Keyboard display security bypass does not allow telecommunication access
without first correcting the security code.
Note These features are not operable in CR1000KDs with serial numbers less
than 1263. Contact Campbell Scientific for information on upgrading the
CR1000KD operating system.
8.11.3 Passwords
Passwords are used to secure IP based communications. They are set in various
telecommunication schemes with the .csipasswd file, CRBasic PakBus
instructions, CRBasic TCP/IP instructions, and in CR1000 settings.
8.11.3.1 .csipasswd
The .csipasswd file is a file created and edited through DevConfig (p. 111), and
which resides on the CPU: drive of the CR1000. It contains credentials
(usernames and passwords) required to access datalogger functions over IP
telecommunications. See Web Service API (p. 423) for details concerning the
.csipasswd file.
8.11.3.2 PakBus Instructions
The following CRBasic PakBus instructions have provisions for password
protection:
x
x
x
x
x
x
x
470
ModemCallBack()
SendVariable()
SendGetVariables()
SendFile()
GetVariables()
GetFile()
GetDataRecord()
Section 8. Operation
8.11.3.3 TCP/IP Instructions
The following CRBasic instructions that service CR1000 IP capabilities have
provisions for password protection:
x
x
x
EMailRecv()
EMailSend()
FTPClient()
8.11.3.4 Settings — Passwords
Settings, which are accessible with DevConfig (p. 111), enable the entry of the
following passwords:
x
x
x
x
x
x
PPP Password
PakBus/TCP Password
FTP Password
TLS Password (Transport Layer Security (TLS) Enabled)
TLS Private Key Password
AES-128 Encrypted PakBus Communication Encryption (p. 471) Key
See the section Status, Settings, and DTI (Registers (p. 114)) for more information.
8.11.4 File Encryption
Encryption is available for CRBasic program files and provides a means of
securing proprietary code or making a program tamper resistant. .CR<X> files, or
files specified by the Include() instruction, can be encrypted. The CR1000
decrypts program files on the fly. While other file types can be encrypted, no tool
is provided for decryption.
The CRBasic Editor encryption facility (Menus | File | Save and Encrypt)
creates an encrypted copy of the original file in PC memory. The encrypted file is
named after the original, but the name is appended with "_enc". The original file
remains intact. The FileEncrypt() instruction encrypts files already in CR1000
memory. The encrypted file overwrites and takes the name of the original. The
Encryption() instruction encrypts and decrypts the contents of a file.
One use of file encryption may be to secure proprietary code but make it available
for copying.
8.11.5 Communication Encryption
PakBus is the CR1000 root communication protocol. By encrypting certain
portions of PakBus communications, a high level of security is achieved. See
PakBus Encryption (p. 406) for more information.
8.11.6 Hiding Files
The option to hide CRBasic program files provides a means, apart from or in
conjunction with file encryption, of securing proprietary code, prevent it from
being copied, or making it tamper resistant. .CR<X> files, or files specified by
the Include() instruction, can be hidden using the FileHide() instruction. The
CR1000 can locate and use hidden files on the fly, but a listing of the file or the
471
Section 8. Operation
file name are not available for viewing. See File Management (p. 382) for more
information.
8.11.7 Signatures
Recording and monitoring system and program signatures are important
components of a security scheme. Read more about use of signatures in
Programming to Use Signatures (p. 169) and Signatures: Example Programs (p. 178).
472
9.
Maintenance — Details
Related Topics:
‡Maintenance — Overview (p. 93)
‡Maintenance — Details (p. 473)
x
x
x
9.1
Protect the CR1000 from humidity and moisture.
Replace the internal lithium battery periodically.
Send to Campbell Scientific for factory calibration every three years.
Protection from Moisture — Details
Protection from Moisture — Overview (p. 93)
Protection from Moisture — Details (p. 99)
Protection from Moisture — Products (p. 660)
When humidity levels reach the dew point, condensation occurs and damage to
CR1000 electronics can result. Effective humidity control is the responsibility of
the user.
The CR1000 module is protected by a packet of silica gel desiccant, which is
installed at the factory. This packet is replaced whenever the CR1000 is repaired
at Campbell Scientific. The module should not normally be opened except to
replace the internal lithium battery.
Adequate desiccant should be placed in the instrumentation enclosure to provide
added protection.
9.2
Replacing the Internal Battery
CAUTION Fire, explosion, and severe-burn hazard. Misuse or improper
installation of the internal lithium battery can cause severe injury. Do not
recharge, disassemble, heat above 100 °C (212 °F), solder directly to the cell,
incinerate, or expose contents to water. Dispose of spent lithium batteries
properly.
The CR1000 contains a lithium battery that operates the clock and SRAM when
the CR1000 is not powered. The CR1000 does not draw power from the lithium
battery while it is fully powered by a power supply (p. 85). In a CR1000 stored at
room temperature, the lithium battery should last approximately three years (less
at temperature extremes). In installations where the CR1000 remains powered,
the lithium cell should last much longer.
While powered from an external source, the CR1000 measures the voltage of the
lithium battery ever 24 hours. This voltage is displayed in the Status table (see the
appendix Status Table and Settings (p. 603)) in the Lithium Battery field. A new
battery supplies approximately 3.6 Vdc. Replace the battery when voltage is
approximately 2.7 Vdc.
x
When the lithium battery is removed (or is allowed to become depleted below
2.7 Vdc and CR1000 primary power is removed), the CRBasic program and
most settings are maintained, but the following are lost:
473
Section 9. Maintenance — Details
o
o
o
o
Run-now and run-on power-up settings.
Routing and communication logs (relearned without user intervention).
Time. Clock will need resetting when the battery is replaced.
Final-memory data tables.
A replacement lithium battery can be purchased from Campbell Scientific or
another supplier. Table Internal Lithium-Battery Specifications (p. 474) lists battery
part numbers and key specifications.
Table 127. Internal Lithium-Battery Specifications
Manufacturer
Tadiran
Tadiran Model Number
TL-5902/S
Campbell Scientific, Inc. pn
13519
Voltage
3.6 V
Capacity
1.2 Ah
Self-discharge rate
1%/year @ 20 °C
Operating temperature range
–55 to 85 °C
When reassembling the module to the wiring panel, check that the module is fully
seated or connected to the wiring panel by firmly pressing them together by hand.
Figure 127.
Loosen Retention Screws
Fully loosen (only loosen) the two knurled thumbscrews. They will remain
attached to the module.
474
Section 9. Maintenance — Details
Figure 128.
Pull Edge Away from Panel
Pull one edge of the canister away from the wiring panel to loosen it from three
internal connector seatings.
Figure 129.
Remove Nuts to Disassemble Canister
475
Section 9. Maintenance — Details
Remove six nuts, then open the clam shell.
Figure 130.
Remove and Replace Battery
Remove the lithium battery by gently prying it out with a small flat point
screwdriver. Reverse the disassembly procedure to reassemble the CR1000.
Take particular care to ensure the canister is reseated tightly into the three
connectors.
9.3
Factory Calibration or Repair Procedure
Related Topics
‡Auto Calibration — Overview (p. 92)
‡Auto Calibration — Details (p. 344)
‡Auto-Calibration — Errors (p. 490)
‡Offset Voltage Compensation (p. 323)
‡Factory Calibration (p. 94)
‡Factory Calibration or Repair Procedure (p. 476)
If sending the CR1000 to Campbell Scientific for calibration or repair, consult
first with a Campbell Scientific application engineer. If the CR1000 is
malfunctioning, be prepared to perform some troubleshooting procedures while
on the phone with the application engineer. Many problems can be resolved with
a telephone conversation. If calibration or repair is needed, the following
procedures should be followed when sending the product:
Products may not be returned without prior authorization. The following contact
information is for US and International customers residing in countries served by
Campbell Scientific, Inc. directly. Affiliate companies handle repairs for
customers within their territories. Please visit www.campbellsci.com to determine
which Campbell Scientific company serves your country.
To obtain a Returned Materials Authorization (RMA), contact CAMPBELL
SCIENTIFIC, INC., phone (435) 227-2342. After an application engineer
determines the nature of the problem, an RMA number will be issued. Please
write this number clearly on the outside of the shipping container. Campbell
476
Section 9. Maintenance — Details
Scientific's shipping address is:
CAMPBELL SCIENTIFIC, INC.
RMA#_____
815 West 1800 North
Logan, Utah 84321-1784
For all returns, the customer must fill out a "Statement of Product Cleanliness and
Decontamination" form and comply with the requirements specified in it. The
form is available from our web site at www.campbellsci.com/repair. A completed
form must be either emailed to [email protected] or faxed to 435-2279579. Campbell Scientific is unable to process any returns until we receive this
form. If the form is not received within three days of product receipt or is
incomplete, the product will be returned to the customer at the customer's
expense. Campbell Scientific reserves the right to refuse service on products that
were exposed to contaminants that may cause health or safety concerns for our
employees.
477
10. Troubleshooting
If a system is not operating properly, please contact a Campbell Scientific
application engineer for assistance. When using sensors, peripheral devices, or
telecommunication hardware, look to the manuals for those products for
additional help.
Note If a Campbell Scientific product needs to be returned for repair or
recalibration, a Return Materials Authorization (p. 3) number is first required.
Please contact a Campbell Scientific application engineer.
10.1
Troubleshooting — Essential Tools
x
x
x
10.2
Multimeter (combination volt meter and resistance meter). Inexpensive
($20.00) meters are useful. The more expensive meters have additional
modes of operation that are useful in some situations.
Cell or satellite phone with contact information for Campbell Scientific
application engineers. Establish a current contact at Campbell Scientific
before going to the field. An application engineer may be able to provide you
with information that will better prepare you for the field visit.
Product documentation in a reliable format and easily readable at the
installation site. Sun glare, dust, and moisture often make electronic media
difficult to use and unreliable.
Troubleshooting — Basic Procedure
1. Check the voltage of the primary power source at the POWER IN terminals on
the face of the CR1000.
2. Check wires and cables for the following:
o
o
o
o
Loose connection points
Faulty connectors
Cut wires
Damaged insulation, which allows water to migrate into the cable.
Water, whether or not it comes in contact with wire, can cause system
failure. Water may increase the dielectric constant of the cable
sufficiently to imped sensor signals, or it may migrate into the sensor,
which will damage sensor electronics.
3. Check the CRBasic program. If the program was written solely with Short Cut,
the program is probably not the source of the problem. If the program was
written or edited with CRBasic Editor, logic and syntax errors could easily
have crept into the code. To troubleshoot, create a stripped down version of
the program, or break it up into multiple smaller units to test individually. For
example, if a sensor signal-to-data conversion is faulty, create a program that
only measures that sensor and stores the data, absent from all other inputs and
data. Write these mini-programs before going to the field, if possible.
10.3
Troubleshooting — Error Sources
Data acquisition systems are complex, the possible configurations endless, and
permutations mind boggling. Nevertheless, by using a systematic approach using
479
Section 10. Troubleshooting
the principle of independent verification, the root cause of most errors can be
determined and remedies put into effect.
Errors are indicated by multiple means, a few of which actually communicate
using the word Error. Things that indicate that a closer look should be taken
include:
x
x
x
x
x
Error
NAN
INF
Rapidly changing measurements
Incorrect measurements
These occur in different forms and in different places.
A key concept in troubleshooting is the concept of independent verification,
which is use of outside references to verify the function of dis-function of a
component of the system. For example, a multimeter is an independent
measurement device that can be used to check sensor signal, sensor resistance,
power supplies, cable continuity, excitation and control outputs, and so forth.
A very good place to start looking for trouble is in the data produced by the
system. At the root, you must be able to look at the data and determine if it falls
within a reasonable range. For example, consider an application measuring
photosynthetic photon flux (PPF). PPF ranges from 0 (dark) to about 2000
μmoles m-–2 s-–1. If the measured value is less than 0 or greater than 2000, an
error is probably being introduced somewhere in the system. If the measured
value is 1000 at noon under a clear summer sky, an error is probably being
introduced somewhere in the system.
Error sources usually fall into one or more of the following categories:
x
CRBasic program
o
o
o
x
Hardware
o
o
o
o
o
o
x
480
Operating system bugs are rare, but possible.
Datalogger support software
o
x
Mis-wired sensors or power sources are common.
Damaged hardware
Water, humidity, lightning, voltage transients, EMF
Visible symptoms
Self-diagnostics
Watchdog errors
Firmware
o
x
if the program was written completely by Short Cut, errors are very rare.
if the program was written or edited by a person, errors are much more
common.
Channel assignments, input-range codes, and measurement mode
arguments are common sources of error.
Bugs are uncommon, but do occur.
Externally caused errors
Section 10. Troubleshooting
10.4
Troubleshooting — Status Table
Information in the Status table lends insight into many problems. The appendix
Status Table and Settings (p. 603) documents Status table registers and provides
some insights as to how to use the information in troubleshooting.
Review the section Status Table as Debug Resource (p. 485). Many of these errors
match up with like-sounding errors in the Station Status utility in datalogger
support software.
10.5
Programming
Analyze data soon after deployment to ensure the CR1000 is measuring and
storing data as intended. Most measurement and data-storage problems are a
result of one or more CRBasic program bugs.
10.5.1 Program Does Not Compile
Although the CRBasic Editor compiler states that a program compiles OK, the
program may not run or even compile in the CR1000. This is rare, but reasons
may include:
x
x
The CR1000 has a different (usually older) operating system that is not fully
compatible with the PC compiler. Check the two versions if in doubt. The
PC compiler version is shown on the first line of the compile results.
The program has large memory requirements for data tables or variables and
the CR1000 does not have adequate memory. This normally is flagged at
compile time, in the compile results. If this type of error occurs, check the
following:
o
o
Copies of old programs on the CPU: drive. The CR1000 keeps copies of
all program files unless they are deleted, the drive is formatted, or a new
operating system is loaded with DevConfig (p. 111).
That the USR: drive, if created, is not too large. The USR: drive may be
using memory needed for the program.
o
that a program written for a 4 MB CR1000 is being loaded into a 2 MB
CR1000.
o
that a memory card (CF) is not available when a program is attempting to
access the CRD: drive. This can only be a problem if a TableFile() or
CardOut() instruction is included in the program.
10.5.2 Program Compiles / Does Not Run Correctly
If the program compiles but does not run correctly, timing discrepancies are often
the cause. Neither CRBasic Editor nor the CR1000 compiler attempt to check
whether the CR1000 is fast enough to do all that the program specifies in the time
allocated. If a program is tight on time, look further at the execution times. Check
the measurement and processing times in the Status table (MeasureTime,
ProcessTime, MaxProcTime) for all scans, then try experimenting with the
InstructionTimes() instruction in the program. Analyzing InstructionTimes()
results can be difficult due to the multitasking nature of the logger, but it can be a
useful tool for fine tuning a program.
481
Section 10. Troubleshooting
10.5.3 NAN and ±INF
NAN (not-a-number) and ±INF (infinite) are data words indicating an exceptional
occurrence in datalogger function or processing. NAN is a constant that can be
used in expressions as shown in the following code snip that sets a CRBasic
control feature (a flag) if the wind direction is NAN:
If WindDir = NAN Then
WDFlag = False
Else
WDFlag = True
EndIf
NAN can also be used in conjunction with the disable variable (DisableVar) in
output processing (data storage) instructions as shown in CRBasic example Using
NAN to Filter Data (p. 484).
10.5.3.1 Measurements and NAN
A NAN indicates an invalid measurement.
10.5.3.1.1
Voltage Measurements
The CR1000 has the following user-selectable voltage ranges: ±5000 mV, ±2500
mV, ±250 mV, and ±25 mV. Input signals that exceed these ranges result in an
over-range indicated by a NAN for the measured result. With auto range to
automatically select the best input range, a NAN indicates that either one or both
of the two measurements in the auto-range sequence over ranged. See the section
Calibration Errors (p. 490).
A voltage input not connected to a sensor is floating and the resulting measured
voltage often remains near the voltage of the previous measurement. Floating
measurements tend to wander in time, and can mimic a valid measurement. The
C (open input detect/common-mode null) range-code option is used to force a
NAN result for open (floating) inputs.
10.5.3.1.2
SDI-12 Measurements
NAN is loaded into the first SDI12Recorder() variable under the following
conditions:
x
x
x
x
CR1000 is busy with terminal commands
When the command is an invalid command.
When the sensor aborts with CR LF and there is no data.
When 0 is returned for the number of values in response to the M! or C!
command.
10.5.3.2 Floating-Point Math, NAN, and ±INF
Table Math Expressions and CRBasic Results (p. 483) lists math expressions, their
CRBasic form, and IEEE floating point-math result loaded into variables declared
as FLOAT or STRING.
482
Section 10. Troubleshooting
10.5.3.3 Data Types, NAN, and ±INF
NAN and ±INF are presented differently depending on the declared-variable data
type. Further, they are recorded differently depending on the final-memory data
type chosen compounded with the declared-variable data type used as the source
(table Variable and FS Data Types with NAN and ±INF (p. 483) ). For example,
INF, in a variable declared As LONG, is represented by the integer –
2147483648. When that variable is used as the source, the final-memory word
when sampled as UINT2 is stored as 0.
Table 128. Math Expressions and CRBasic Results
Expression
CRBasic Expression
Result
0/0
0 / 0
NAN
’– ’
(1 / 0) - (1 / 0)
NAN
-1 ^ (1 / 0)
NAN
‡–’
0 ‡ (-1 ‡ (1 / 0))
NAN
“’“’
(1 / 0) / (1 / 0)
NAN
’
1 ^ (1 / 0)
NAN
‡’
0 ‡ (1 / 0)
NAN
x/0
1 / 0
INF
x / –0
1 / -0
INF
-x / 0
-1 / 0
-INF
-x / –0
-1 / -0
-INF
0
(1 / 0) ^ 0
INF
’
0 ^ (1 / 0)
0
0
0 ^ 0
1
(–1)
1
’
0
0
’
483
Section 10. Troubleshooting
Table 129. Variable and Final-Memory Data Types with NAN and ±INF
Final-Memory Data Type & Associated Stored Values
Variable
Type
Test
Expression
Public /
Dim
Variables
FP2
As FLOAT
1/0
INF
INF
INF
65535
0/0
NAN
NAN
NAN
1/0
2,147,483,64
7
7999
0/0
2,147,483,64
8
1/0
As LONG
As Boolean
As
STRING
1
2
3
IEEE4
UNIT4
STRING
BOOL
BOOL8
LONG
4294967295
+INF
TRUE
TRUE
2,147,483,647
0
2147483648
NAN
TRUE
TRUE
-2,147,483,648
2.147484E09
65535
2147483647
2147483647
TRUE
TRUE
2,147,483,647
-7999
2.147484E09
0
2147483648
-2147483648
TRUE
TRUE
-2,147,483,648
TRUE
-1
-1
65535
4294967295
-1
TRUE
TRUE
-1
0/0
TRUE
-1
-1
65535
4294967295
-1
TRUE
TRUE
-1
1/0
+INF
INF
INF
65535
2147483647
+INF
TRUE
TRUE
2147483647
0/0
NAN
NAN
NAN
0
3
2147483648
NAN
TRUE
TRUE
-2147483648
1
1
UINT2
2
Except Average() outputs NAN
Except Average() outputs 0
65535 in operating systems prior to v. 28
10.5.3.4 Output Processing and NAN
When a measurement or process results in NAN, any output process with
DisableVar = FALSE that includes an NAN measurement. For example,
Average(1,TC_TempC,FP2,False)
will result in NAN being stored as final-storage data for that interval.
However, if DisableVar is set to TRUE each time a measurement results in NAN,
only non-NAN measurements will be included in the output process. CRBasic
example Using NAN to Filter Data (p. 484) demonstrates the use of conditional
statements to set DisableVar to TRUE as needed to filter NAN from output
processes.
Note If all measurements result in NAN, NAN will be stored as final-storage data
regardless of the use of DisableVar.
484
Section 10. Troubleshooting
CRBasic Example 69.
Using NAN to Filter Data
'This program example demonstrates the use of NAN to filter what data are used in output processing
functions such as
'averages, maxima, and minima.
'Declare Variables and Units
Public TC_RefC
Public TC_TempC
Public DisVar As Boolean
'Define Data Tables
DataTable(TempC_Data,True,-1)
DataInterval(0,30,Sec,10)
Average(1,TC_TempC,FP2,DisVar)
EndTable
'Output process
'Main Program
BeginProg
Scan(1,Sec,1,0)
'Measure Thermocouple Reference Temperature
PanelTemp(TC_RefC,250)
'Measure Thermocouple Temperature
TCDiff(TC_TempC,1,mV2_5,1,TypeT,TC_RefC,True,0,250,1.0,0)
'DisVar Filter
If TC_TempC = NAN Then
DisVar = True
Else
DisVar = False
EndIf
'Call Data Tables and Store Data
CallTable(TempC_Data)
NextScan
EndProg
10.5.4 Status Table as Debug Resource
Related Topics:
‡Status, Settings, and Data Table Information (Status/Settings/DTI) (p. 603)
‡Common Uses of the Status Table (p. 604)
‡Status Table as Debug Resource (p. 485)
Consult the CR1000 Status table when developing a program or when a problem
with a program is suspected. Critical Status table registers to review include
CompileResults, SkippedScan, SkippedSlowScan, SkippedRecord,
ProgErrors, MemoryFree, VarOutOfBounds, WatchdogErrors and
Calibration.
10.5.4.1 CompileResults
CompileResults reports messages generated by the CR1000 at program upload
and compile-time. Messages may also added as the program runs. Error
485
Section 10. Troubleshooting
messages may not be obvious because the display is limited. Much of this
information is more easily accessed through the datalogger support software (p. 95)
station status report. The message reports the following:
x
x
x
x
x
x
program compiled OK
warnings about possible problems
run-time errors
variables that caused out-of-bounds conditions
watchdog information
memory errors
Warning messages are posted by the CRBasic compiler to advise that some
expected feature may not work. Warnings are different from error messages in
that the program will still operate when a warning condition is identified.
A rare error is indicated by mem3 fail type messages. These messages can be
caused by random internal memory corruption. When seen on a regular basis with
a given program, an operating system error is indicated. Mem3 fail messages are
not caused by user error, and only rarely by a hardware fault. Report any
occurrence of this error to a Campbell Scientific application engineer, especially if
the problem is reproducible. Any program generating these errors is unlikely to be
running correctly.
Examples of some of the more common warning messages are listed in table
Warning Message Examples (p. 486).
Table 130. Warning Message Examples
Message
CPU:DEFAULT.CR1 -- Compiled in
PipelineMode.
Error(s) in CPU:NewProg.CR1:
line 13: Undeclared variable Battvolt.
486
Meaning
A new program sent to the datalogger failed to
compile, and the datalogger reverted to running
DEFAULT.cr1.
Warning: Cannot open include file CPU:
Filename.cr1
The filename in the Include instruction does not
match any file found on the specified drive.
Since it was not found, the portion of code
referenced by Include will not be executed.
Warning: Cannot open voice.txt
voice.txt, a file required for use with a COM310
voice phone modem, was not found on the CPU:
drive.
Warning: COM310 word list cannot be a
variable.
The Phrases parameter of the VoicePhrases()
instruction was assigned a variable name instead
of the required string of comma-separated words
from the Voice.TXT file.
Warning: Compact Flash Module not
detected: CardOut not used.
CardOut() instructions in the program will be
ignored because no CompactFlash (CF) card was
detected when the program compiled.
Warning: EndIf never reached at runtime.
Program will never execute the EndIf
instruction. In this case, the cause is a Scan()
with a Count parameter of 0, which creates an
infinite loop within the program logic.
Section 10. Troubleshooting
Table 130. Warning Message Examples
Message
Meaning
Warning: Internal Data Storage Memory
was re-initialized.
Sending a new program has caused finalmemory to be re-allocated. Previous data are no
longer accessible.
Warning: Machine self-calibration failed.
Indicates a problem with the analog
measurement hardware during the self
calibration. An invalid external sensor signal
applying a voltage beyond the internal r8 Vdc
supplies on a voltage input can induce this error.
Removing the offending signal and powering up
the logger will initiate a new self-calibration. If
the error does not occur on power-up, the
problem is corrected. If no invalid external
signals are present and / or self-calibration fails
again on power-up, the CR1000 should be
repaired by a qualified technician.
Warning: Slow Seq 1, Scan 1, will skip
scans if running with Scan 1
SlowSequence scan rate is <= main scan rate.
This will cause skipped scans on the
SlowSequence.
Warning: Table [tablename] is declared
but never called.
1RGDWDZLOOEHVWRUHGLQ>[email protected]
there is no CallTable() instruction in the
program that references that table.
Warning: Units:
a_units_name_that_is_more_than_38_char
a... too long will be truncated to 38 chars.
The label assigned with the Units argument is
too long and will be truncated to the maximum
allowed length.
Warning: Voice word TEH is not in
Voice.TXT file
The misspelled word TEH in the VoiceSpeak()
instruction is not found in Voice.TXT file and
will not be spoken by the voice modem.
10.5.4.2 SkippedScan
Skipped scans are caused by long programs with short scan intervals, multiple
Scan() / NextScan instructions outside a SubScan() or SlowSequence, or by
other operations that occupy the processor at scan start time. Occasional skipped
scans may be acceptable but should be avoided. Skipped scans may compromise
frequency measurements made on terminals configured for pulse input. The error
occurs because counts from a scan and subsequent skipped scans are regarded by
the CR1000 as having occurred during a single scan. The measured frequency
can be much higher than actual. Be careful that scans that store data are not
skipped. If any scan skips repeatedly, optimization of the datalogger program or
reduction of on-line processing may be necessary.
Skipped scans in Pipeline Mode indicate an increase in the maximum buffer depth
is needed. Try increasing the number of scan buffers (third parameter of the
Scan() instruction) to a value greater than that shown in the MaxBuffDepth
register in the Status table.
10.5.4.3 SkippedSlowScan
The CR1000 automatically runs a slow sequence to update the calibration table.
When the calibration slow sequence skips, the CR1000 will try to repeat that step
of the calibration process next time around. This simply extends calibration time.
487
Section 10. Troubleshooting
10.5.4.4 SkippedRecord
SkippedRecord is normally incremented when a write-to-data-table event is
skipped, which usually occurs because a scan is skipped. SkippedRecord is not
incremented by all events that leave gaps in data, including cycling power to the
CR1000.
10.5.4.5 ProgErrors
Should be 0. If not, investigate.
10.5.4.6 MemoryFree
A number less than 4 kB is too small and may lead to memory-buffer related
errors.
10.5.4.7 VarOutOfBounds
Related Topics:
‡ Declaring Arrays (p. 135)
‡$UUD\VRI0XOWLSOLHUVDQG2IIVHWV
‡VarOutOfBounds (p. 488)
When programming with variable arrays, care must be taken to match the array
size to the demands of the program. For example, if an operation attempts to
write to 16 elements in array ExArray(), but ExArray() was declared with 15
elements (for example, Public ExArray(15)), the VarOutOfBound runtime error
counter is incremented in the Status table each time the absence of a sixteenth
element is encountered.
The CR1000 attempts to catch VarOutOfBound errors at compile time (not to be
confused with the CRBasic Editor pre-compiler, which does not). When a
VarOutOfBound error is detected at compile time, the CR1000 attempts to
document which variable is out of bounds at the end of the CompileResults
message in the Status table. For example, the CR1000 may detect that
ExArray() is not large enough and write Warning:Variable ExArray out of
bounds to the CompileErrors register.
The CR1000 does not catch all out-of-bounds errors, so take care that all arrays
are sized as needed.
10.5.4.8 Watchdog Errors
Watchdog errors indicate the CR1000 has crashed and reset itself. A few
watchdogs indicate the CR1000 is working as designed and are not a concern.
Following are possible root causes sorted in order of most to least probable:
x
x
x
x
488
Transient voltage
Running the CRBasic program very fast
Many PortSet() instructions back-to-back with no delay
High-speed serial data on multiple ports with very large data packets or bursts
of data
Section 10. Troubleshooting
If any of the previous are not the apparent cause, contact a Campbell Scientific
application engineer for assistance. Causes that require assistance include the
following:
x
x
x
Memory corruption. Check for memory failures with M command in
terminal mode (p. 501).
Operating-system problem
Hardware problem
Watchdog errors may cause telecommunication disruptions, which can make
diagnosis and remediation difficult. The CR1000KD Keyboard Display will often
work as a user interface when telecommunications fail. Information on CR1000
crashes may be found in three places.
x
x
x
10.5.4.8.1
WatchdogErrors field in the Status table (p. 603)
Watchdog.txt file on the CPU: drive (p. 374). Some time may elapse between
when the error occurred and the Watchdog.txt file is created. Not all errors
cause a file to be created. Any time a watchdog.txt file is created, please
consult with a Campbell Scientific application engineer.
Crash information may be posted at the end of the CompileResults register
in the Status (p. 603) table.
Status Table WatchdogErrors
Non-zero indicates the CR1000 has crashed, which can be caused by power or
transient-voltage problems, or an operating-system or hardware problem. If
power or transient problems are ruled out, the CR1000 probably needs an
operating-system update or repair (p. 3) by Campbell Scientific.
10.5.4.8.2
Watchdoginfo.txt File
A WatchdogInfo.txt file is created on the CPU: drive when the CR1000
experiences a software reset (as opposed to a hardware reset that increment the
WatchdogError register in the Status table). Postings of WatchdogInfo.txt
files are rare. Please consult with a Campbell Scientific application engineer at
any occurrence.
Debugging beyond identifying the source of the watchdog is quite involved.
Please contact a Campbell Scientific application engineer for assistance. Key
things to look for include the following:
x
x
x
Are multiple tasks waiting for the same resource? This is always caused by a
software bug.
In newer operating systmes, there is information about the memory regions. If
anything like ColorX: fail is seen, this means that the memory is corrupted.
The comms memory information can also be a clue for PakBus and TCP
triggered watchdogs. For example, if COM1 is the source of the watchdog,
knowing exactly what is connected to the port and at what baud rate and
frequency (how often) the port is communicating are valuable pieces of
information.
489
Section 10. Troubleshooting
10.6
Troubleshooting — Operating Systems
Updating the CR1000 operating system will sometimes fix a problem. Operating
systems are available, free of charge, at www.campbellsci.com/downloads
(http://www.campbellsci.com/downloads).
Operating systems undergo extensive testing prior to release by a professional
team of product testers. However, the function of any new component to a dataacquisition system should be thoroughly examined and tested by the integrator
and end user.
10.7
Troubleshooting — Auto-Calibration Errors
Related Topics
‡Auto Calibration — Overview (p. 92)
‡Auto Calibration — Details (p. 344)
‡Auto-Calibration — Errors (p. 490)
‡Offset Voltage Compensation (p. 323)
‡Factory Calibration (p. 94)
‡Factory Calibration or Repair Procedure (p. 476)
Auto-calibration errors are rare. When they do occur, the cause is usually an
analog input that exceeds the input limits (p. 310) of the CR1000.
x
x
x
x
10.8
Check all analog inputs to make sure they are not greater than ±5 Vdc by
measuring the voltage between the input and a G terminal. Do this with a
multimeter (p. 520).
Check for condensation, which can sometimes cause leakage from a 12 Vdc
source terminal into other places.
Check for a lose ground wire on a sensor powered from a 12V or SW12
terminal.
If a multimeter is not available, disconnect sensors, one at a time, that require
power from 9 to 16 Vdc. If measurements return to normal, you have found
the cause.
Communications
10.8.1 RS-232
Baud rate mis-match between the CR1000 and datalogger support software (p. 95)
is often the cause of communication problems. By default, CR1000 baud rate
auto-adjusts to match that of the software. However, settings changed in the
CR1000 to accommodate a specific RS-232 device, such as a smart sensor,
display or modem, may confine the RS-232 port to a single baud rate. If the baud
rate can be guessed at and entered into support software parameters,
communications may be established. Once communications are established,
CR1000 baud rate settings can be changed. Clues as to what the baud rate may be
set at can be found by analyzing current and previous CR1000 programs for the
SerialOpen() instruction, since SerialOpen() specifies a baud rate.
Documentation provided by the manufacturer of the previous RS-232 device may
also hint at the baud rate.
490
Section 10. Troubleshooting
10.8.2 Communicating with Multiple PCs
The CR1000 can communicate with multiple PCs simultaneously. For example,
the CR1000 may be a node of an internet PakBus network communicating with a
distant instance of LoggerNet. An onsite technician can communicate with the
CR1000 using PC200W with a serial connection, so long as the PakBus addresses
of the host PCs are different. All Campbell Scientific datalogger support software
include an option to change PC PakBus addressing.
10.8.3 Comms Memory Errors
CommsMemFree() is an array of three registers in the Status table (p. 603) that
report communication memory errors. In summary, if any CommsMemFree()
register is at or near zero, assistance may be required from Campbell Scientific to
diagnose and correct a potentially serious communication problem. Sections
CommsMemFree(1) (p. 491), CommsMemFree(2) (p. 492), and CommsMemFree(3) (p.
493) explain the possible communication memory errors in detail.
10.8.3.1 CommsMemFree(1)
CommsMemFree(1): Number of buffers used in all communication, except with
the CR1000KD Keyboard Display. Two digits per each buffer size category.
Most significant digits specify the number of larger buffers. Least significant
digits specify the number of smaller buffers. When TLS (p. 531) is not active, there
are four-buffer categories: tiny, little, medium, and large. When TLS is active,
there is a fifth category, huge, and more buffers are allocated for each category.
When a buffer of a certain size is required, the smallest, suitably-sized pool that
still has at least one buffer free will allocate a buffer and decrement the number in
reserve. When the communication is complete, the buffer is returned to the pool
and the number for that size of buffer will increment.
When TLS is active, the number of buffers allocated for tiny can only be
displayed as the number of tiny buffers modulo divided by 100.
CommsMemFree(1) is encoded using the following expression:
CommsMemFree(1) = tiny + lil*100 + mid*10000 + med*1000000 +
lrg*100000000
where,
tiny = number of 16-byte packets available
lil QXPEHURIOLWWOH§E\WHVSDFNHWV
mid QXPEHURIPHGLXPVL]H§E\WHVSDFNHWV
med QXPEHURIELJ§N%SDFNHWV
lrg QXPEHURIODUJH§ kB) packets available, primarily for TLS.
491
Section 10. Troubleshooting
The following expressions are used to pick the individual values from
CommsMemFree(1):
tiny = CommsMemFree(1)
lil = (CommsMemFree(1)
mid = (CommsMemFree(1)
med = (CommsMemFree(1)
lrg = (CommsMemFree(1)
%
/
/
/
/
100
100) % 100
10000) % 100
1000000) % 100
100000000) % 100
Table 131. CommsMemFree(1) Defaults and Use Example, TLS Not
Active
Use Example
Buffer
Catagory
Condition:
reset, TLS not active.
Buffer count:
CommsMemFree(1) =
15251505.
Condition:
in use, TLS not active.
Buffer count:
CommsMemFree(1) =
13241504.
Numbers of
buffers in use
(reset count –
in-use count)
tiny
05
04
1
little
15
15
0
medium
25
24
1
large
15
13
2
huge
Table 132. CommsMemFree(1) Defaults and Use Example, TLS
Active
Use Example
Condition:
TLS enabled, no
active
TLS connections.
Connected to
LoggerNet on
TCP/IP.
Buffer Count:
CommsMemFree(1) =
228968437.
Buffer
Category
Condition:
reset, TLS active.
Buffer count:
CommsMemFree(1) =
230999960.
tiny
160
137
23
little
99
84
15
medium
99
96
3
large
30
28
2
1
2
2
0
huge
1
Numbers of buffers
in use (reset count –
in-use count)
If email clients using TLS are active, huge will be decremented along with some of the others.
10.8.3.2 CommsMemFree(2)
CommsMemFree(2) displays the number of memory "chunks" in "keep" memory
(p. 519) used by communications. It includes memory used for PakBus routing and
neighbor lists, communication timeout structures, and TCP/IP connection
structures. The PakBusNodes setting, which defaults to 50, is included in
492
Section 10. Troubleshooting
CommsMemFree(2). Doubling PakBusNodes to 100 doubles
CommsMemFree(2) IURP§WR§DVVXPLQJDODUJH3DN%XVQHWZRUNKDV
not been just discovered). The larger the discovered PakBus network, and the
larger the number of simultaneous TCP connections, the smaller
CommsMemFree(2) number will be. A PakBusNodes setting of 50 is normally
enough, and can probably be reduced in small networks to free memory, if
needed. Reducing PakBusNodes by one frees 224 bytes. If
CommsMemFree(2) drops and stays down for no apparent reason (a very rare
occurrence), please contact a Campbell Scientific application engineer since the
CR1000 operating system may need adjustment.
10.8.3.3 CommsMemFree(3)
CommsMemFree(3) Specifies three two-digit fields, from right (least
significant) to left (most significant):
x
x
x
lilfreeq = "little" IP packets available
bigfreeq = "big" IP packets available
rcvdq = IP packets in the received queue (not yet processed)
At start up, with no TCP/IP communication occurring, this field will read 1530,
which is interpreted as 30 lilfreeq and 15 bigfreeq available, with no packets in
rcvdq. The Ethernet and/or the PPP interface feed rcvdq. If
CommsMemFree(3) has a reading of 21428, then two packets are in the received
queue, 14 bigfreeq packets are free (one in use), and 28 lilfreeq are free (two in
use). These three pieces of information are also reported in the IP trace (p. 518)
information every 30 seconds as lilfreeq, bigfreeq, and recvdq. If lilfreeq or
bigfreeq free packets drop and stay near zero, or if the number in rcvdq climbs
and stays high (all are rare occurrences), please contact a Campbell Scientific
application engineer as the operating system may need adjustment.
CommsMemFree(3) is encoded as follows:
CommsMemFree(3) = lilfreeq + bigfreeq*100 + rcvdq*10000 +
sendq*1000000
where,
lilfreeq = number of small TCP packets available
bigfreeq = number of large TCP packets
rcvdq = number of input packets currently waiting to be serviced
sendq = number of output packets waiting to be sent
The following expressions can be used to pick the values out of the
CommsMemFree(3) variable:
lilfreeq = CommsMemFree(3) % 100
bigfreeq = (CommsMemFree(3) / 100) % 100
rcvdq = (CommsMemFree(3) / 10000) % 100
sendq = (CommsmemFree(3) / 1000000) % 100
493
Section 10. Troubleshooting
10.9
Troubleshooting — Power Supplies
Related Topics:
‡3RZHU6XSSOLHV — Specifications
‡Power Supplies — Quickstart (p. 44)
‡Power Supplies — Overview (p. 85)
‡Power Supplies — Details (p. 100)
‡Power Supplies — Products (p. 657)
‡Power Sources (p. 101)
‡Troubleshooting — Power Supplies (p. 494)
10.9.1 Troubleshooting Power Supplies — Overview
Power-supply systems may include batteries, charging regulators, and a primary
power source such as solar panels or ac/ac or ac/dc transformers attached to mains
power. All components may need to be checked if the power supply is not
functioning properly.
The section Diagnosis and Fix Procedures (p. 495) includes the following
flowcharts for diagnosing or adjusting power equipment supplied by Campbell
Scientific:
x
x
x
x
Battery-voltage test
Charging-circuit test (when using an unregulated solar panel)
Charging-circuit test (when using a transformer)
Adjusting charging circuit
If power supply components are working properly and the system has peripherals
with high current drain, such as a satellite transmitter, verify that the power supply
is designed to provide adequate power. Information on power supplies available
from Campbell Scientific can be obtained at www.campbellsci.com. Basic
information is available in the appendix Power Supplies (p. 657).
10.9.2 Troubleshooting Power Supplies — Examples -- 8 10 30
Symptom:
o
o
CRBasic program does not execute.
Low12VCount of the Status table displays a large number.
Possible affected equipment:
o
o
o
o
Batteries
Charger/regulators
Solar panels
Transformers
Likely causes:
o
o
o
494
Batteries may need to be replaced or recharged.
Charger/regulators may need to be fixed or re-calibrated.
Solar panels or transformers may need to be fixed or replaced.
Section 10. Troubleshooting
10.9.3 Troubleshooting Power Supplies — Procedures
Required Equipment:
o
o
o
Voltmeter
NȍUHVLVWRU
ȍZDWWUHVLVWRUIRUWKHFKDUJLQJFLUFXLWWHVWVDQGWRDGMXVWWKH
charging circuit voltage.
10.9.3.1 Battery Test
The procedure outlined in this flow chart tests sealed-rechargeable or alkaline
batteries in the PS100 charging regulator, or a sealed-rechargeable battery
attached to a CH100 charging regulator. If a need for repair is indicated after
following the procedure, see Warranty and Assistance (p. 3) for information on
sending items to Campbell Scientific.
495
Section 10. Troubleshooting
Battery Test
If using a rechargeable power supply,
disconnect the charging source (i.e., solar panel
or ac transformer) from the battery pack. Wait
20 minutes before proceeding with this test.
Test Voltage at Charging Regulator
Set a voltmeter to read dc voltage as high as 15
V. Measure the voltage between a 12V and G
terminal on the charging regulator.
Is the voltage > 11.0 Vdc?
No
Yes
Test the Battery Under Load
Program the CR1000 to measure battery
voltage using a 0.01-second scan rate. Use the
voltmeter to measure the voltage between a
12V and G terminal on the charging regulator.
Is the voltage > 10.8 Vdc?
No
Is the battery a sealed, rechargeable
battery?
No
Yes
,VWKHYROWDJH•9GF"
Replace battery / batteries*
No
Yes
Yes
Recharge battery*
Is the battery voltage > 12 Vdc?
No
Battery voltage is adequate for CR1000 operation. However, if the CR1000 is to function
for a long period, Campbell Scientific recommends replacing, or, if using a sealed,
rechargeable battery, recharging the battery so the voltage is > 12 Vdc.
Yes
The battery is good.
*When using a sealed, rechargeable battery that is recharged with primary power provided by solar panel or ac/ac - ac/dc transformer, testing the
charging regulator is recommended. See Charging Regulator with Solar Panel Test (p. 496) or Charging Regulator with Transformer Test (p. 498).
10.9.3.2 Charging Regulator with Solar-Panel Test
The procedure outlined in this flow chart tests PS100 and CH100 charging
regulators that use solar panels as the power source. If a need for repair is
indicated after following the procedure, see Warranty and Assistance (p. 3) for
information on sending items to Campbell Scientific.
496
Section 10. Troubleshooting
Charging Regulator with Solar-Panel Test
Disconnect any wires attached to the 12V and G (ground) terminals on the PS100 or CH100 charging regulator. Unplug any batteries. Connect the solar panel to the two CHG
terminals. Polarity of inputs does not matter. Only the solar panel should be connected. Set the charging-regulator power switch to OFF.
NOTE This test assumes the solar panel has an unregulated output.
Solar Panel Test
Set a voltmeter to measure dc voltage. Measure solar panel output
across the two solar-panel leads by placing a voltmeter lead on one
CHG terminal, and the other lead on the other CHG terminal. Is the
output 17 to 22 Vdc?
No
Yes
Remove the solar-panel leads from the
charging circuit. Measure solar-panel
output across the two leads. Is the output
> 0 Vdc?
The solar panel is damaged
and should be repaired or
replaced.
No
Yes
,VWKHYROWDJH•9GF"
There may not be enough
sunlight to perform the test,
or the solar panel is damaged.
No
Yes
Reconnect the power source (transformer /
solar panel) to the CHG terminals on the
charging regulator. Measure the voltage
between the two CHG terminals. Is the
Yes YROWDJH•9GF9DF"
No
Nȍ/RDG7HVW
3ODFHDNȍUHVLVWRUEHWZHHQD12V terminal and a G (ground)
terminal on the charging regulator.
2) Switch the power switch to ON.
3) Measure the dc voltage across the resistor.
Is the measured voltage 13.3 to 14.1 V?
Measure the voltage between the two pins
in a battery-connection receptacle. Is the
voltage 10.0 to 15.5 Vdc?
No
Yes
Yes
See Adjusting Charging Voltage (p. 499)
to calibrate the charging regulator, or
return the charging regulator to Campbell
Scientific for calibration.
ȍ/RDG7HVW
1) Switch the power switch to OFF.
2) Disconnect the power source (transformer / solar panel).
5HPRYHWKHNȍUHVLVWRU
3ODFHDȍ:UHVLVWRUEHWZHHQD12V terminal and a G
(ground) terminal on the charging regulator.
5) Reconnect the power source and then switch the power switch to
ON.
7) Measure the voltage across the ends of the resistor.
Is the voltage 13.0 to 14.0 Vdc (13.3 if circuit just adjusted)?
8) Switch the power switch to OFF.
NOTE The resistor will get HOT in just a few seconds. After
measuring the voltage, switch the power switch to OFF and allow the
resistor to cool before removing it.
Yes
Test Completed
The charger is functioning
SURSHUO\5HPRYHWKHȍ
resistor.
No
With the charging regulator still under
load, measure the voltage between the two
CHG terminals. Is the voltage > 15.5
Vdc?
No
Get Repair Authorization
The charging regulator is
damaged and should be
repaired or replaced.
Yes
No
There may not be enough sunlight to
perform the test.
497
Section 10. Troubleshooting
10.9.3.3 Charging Regulator with Transformer Test
The procedure outlined in this flow chart tests PS100 and CH100 charging
regulators that use ac/ac or ac/dc transformers as power source. If a need for
repair is indicated after following the procedure, see Warranty and Assistance (p. 3)
for information on sending items to Campbell Scientific.
498
Section 10. Troubleshooting
Charging Regulator with ac or dc Transformer Test
Disconnect any wires attached to the 12V and G (ground) terminals on the PS100 or CH100 charging regulator. Unplug any batteries. Connect the power input ac or dc transformer to the
two CHG terminals. Polarity of the inputs does not matter. Only the transformer should be connected. Set the charging-regulator power switch to OFF. Connect the transformer to mains
power.
Transformer Test
Determine whether the transformer output is ac or dc voltage (labeling on the
transformer usually identifies the output voltage type). Set a voltmeter to read that
type of voltage. Measure transformer output across the two transformer leads by
placing a voltmeter lead on one CHG terminal, and the other lead on the other
CHG terminal. Is the output 17 to 22 volts?
No
Yes
Taking care not to short the
transformer leads, remove the leads
from the charging regulator.
Measure transformer output across
the two leads. Is the output 17 to 22
Vac / Vdc?
The transformer is damaged and
should be replaced.
No
Yes
Reconnect the power source
(transformer / solar panel) to the
CHG terminals on the charging
regulator. Measure the voltage
between the two CHG terminals. Is
the voltagH•9GF9DF"
No
Yes
Nȍ/RDG7HVW
3ODFHDNȍUHVLVWRUEHWZHHQD12V terminal and a G (ground) terminal on the
charging regulator.
2) Switch the power switch to ON.
3) Measure the dc voltage across the resistor.
Is the measured voltage 13.3 to 14.1 V?
Measure the voltage between the two
pins in a battery-connection
receptacle. Is the voltage 10.0 to
15.5 Vdc?
No
Yes
No
Yes
See Adjusting Charging Voltage (p.
499) to calibrate the charging
regulator, or return the charging
regulator to Campbell Scientific for
calibration.
ȍ/RDG7HVW
1) Switch the power switch to OFF.
2) Disconnect the power source (transformer / solar panel).
5HPRYHWKHNȍUHVLVWRU
3ODFHDȍ:UHVLVWRUEHWZHHQD12V terminal and a G (ground) terminal on
the charging regulator.
5) Reconnect the power source and then switch the power switch to ON.
7) Measure the voltage across the ends of the resistor.
Is the voltage 13.0 to 14.0 Vdc (13.3 if circuit just adjusted)?
8) Switch the power switch to OFF.
NOTE The resistor will get HOT in just a few seconds. After measuring the
voltage, switch the power switch to OFF and allow the resistor to cool before
removing it.
No
Get Repair Authorization
The charging regulator is damaged
and should be repaired or replaced.
Yes
Test Completed
7KHFKDUJHULVIXQFWLRQLQJSURSHUO\5HPRYHWKHȍUHVLVWRU
10.9.3.4 Adjusting Charging Voltage
Note Campbell Scientific recommends that a qualified electronic technician
perform the following procedure.
The procedure outlined in this flow chart tests and adjusts PS100 and CH100
charging regulators. If a need for repair or calibration is indicated after following
the procedure, see Warranty and Assistance (p. 3) for information on sending items
to Campbell Scientific.
499
Section 10. Troubleshooting
Adjusting Charging Circuit
3ODFHDNȍUHVLVWRUEHWZHHQD12V terminal and a G (ground) ground terminal on
WKHFKDUJLQJUHJXODWRU8VHDYROWPHWHUWRPHDVXUHWKHYROWDJHDFURVVWKHNȍUHVLVWRU
2) Connect a power source that supplies a voltage >17 V to the input CHG terminals
of the charging regulator.
3) Adjust pot R3 (see FIGURE. Potentiometer R3 on PS100 and CH100 Charging
Regulators (p. 501) VRWKDWYROWDJHDFURVVWKHNȍUHVLVWRULV9GF
Can the output voltage be set to 13.3 V?
No
Yes
ȍ/RDG7HVW
1) Switch the power switch to OFF.
2) Disconnect the power source (transformer / solar panel).
5HPRYHWKHNȍUHVLVWRU
3ODFHDȍ:UHVLVWRUEHWZHHQD12V terminal and a G (ground) terminal on
the charging regulator.
5) Reconnect the power source and then switch the power switch to ON.
7) Measure the voltage across the ends of the resistor.
Is the voltage 13.0 to 14.0 Vdc (13.3 if circuit just adjusted)?
8) Switch the power switch to OFF.
NOTE The resistor will get HOT in just a few seconds. After measuring the voltage,
switch the power switch to OFF and allow the resistor to cool before removing it.
Yes
Test Completed
7KHFKDUJHULVIXQFWLRQLQJSURSHUO\5HPRYHWKHȍUHVLVWRU
500
Get Repair Authorization
The charging regulator is damaged and
should be repaired or replaced.
No
Section 10. Troubleshooting
Figure 131.
Regulator
Potentiometer R3 on PS100 and CH100 Charger /
10.10 Terminal Mode
Table CR1000 Terminal Commands (p. 502) lists terminal mode options. With
exception of perhaps the C command, terminal options are not necessary to
routine CR1000 operations.
To enter terminal mode, connect a PC to the CR1000 with the same hard-wire
serial connection used in the What You Will Need (p. 46) section. Open a terminal
emulator program. Terminal emulator programs are available in:
x
x
x
Campbell Scientific datalogger support software (p. 95) Terminal Emulator (p.
530) window
DevConfig (Campbell Scientific Device Configuration Utility Software)
Terminal tab
HyperTerminal. Beginning with Windows Vista, HyperTerminal (or another
terminal emulator utility) must be acquired and installed separately.
As shown in figure DevConfig Terminal Tab (p. 503), after entering a terminal
emulator, press Enter a few times until the prompt CR1000> is returned.
Terminal commands consist of a single character and Enter. Sending an H and
Enter will return the terminal emulator menu.
ESC or a 40 second timeout will terminate on-going commands. Concurrent
terminal sessions are not allowed and will result in dropped communications.
501
Section 10. Troubleshooting
Table 133. CR1000 Terminal Commands
Option
502
Description
Use
0
Scan processing time; real time in seconds
Lists technical data concerning program scans.
1
Serial FLASH data dump
Campbell Scientific engineering tool
2
Read clock chip
Lists binary data concerning the CR1000 clock chip.
3
Status
Lists the CR1000 Status table.
4
Card status and compile errors
Lists technical data concerning an installed CF card.
5
Scan information
Technical data regarding the CR1000 scan.
6
Raw A-to-D values
Technical data regarding analog-to-digital conversions.
7
VARS
Lists Public table variables.
8
Suspend / start data output
Outputs all table data. This is not recommended as a
means to collect data, especially over
telecommunications. Data are dumped as non-error
checked ASCII.
9
Read inloc binary
Lists binary form of Public table.
A
Operating system copyright
Lists copyright notice and version of operating system.
B
Task sequencer op codes
Technical data regarding the task sequencer.
C
Modify constant table
Edit constants defined with ConstTable /
EndConstTable. Only active when ConstTable /
EndConstTable in the active program.
D
MTdbg() task monitor
Campbell Scientific engineering tool
E
Compile errors
Lists compile errors for the current program download
attempt.
F
VARS without names
Campbell Scientific engineering tool
G
CPU serial flash dump
Campbell Scientific engineering tool
H
Terminal emulator menu
Lists main menu.
I
Calibration data
Lists gains and offsets resulting from internal calibration
of analog measurement circuitry.
J
Download file dump
Sends text of current program including comments.
K
Unused
L
Peripheral bus read
Campbell Scientific engineering tool
M
Memory check
Lists memory-test results
N
File system information
Lists files in CR1000 memory.
O
Data table sizes
Lists technical data concerning data-table sizes.
P
Serial talk through
Issue commands from keyboard that are passed through
the logger serial port to the connected device. Similar in
concept to SDI12 Talk Through.
REBOOT
Program recompile
Typing “REBOOT” rapidly will recompile the CR1000
program immediately after the last letter, "T", is entered.
Table memory is retained. NOTE When typing
REBOOT, characters are not echoed (printed on
terminal screen).
Section 10. Troubleshooting
Table 133. CR1000 Terminal Commands
Option
SDI12
Description
SDI12 talk through
Use
Issue commands from keyboard that are passed through
the CR1000 SDI-12 port to the connected device.
Similar in concept to Serial Talk Through.
T
Unused
U
Data recovery
Provides the means by which data lost when a new
program is loaded may be recovered. See section
Troubleshooting — Data Recovery (p. 504) for details.
V
Low level memory dump
Campbell Scientific engineering tool
W
Comms Watch
Enables monitoring of CR1000 communication traffic.
X
Peripheral bus module identify
Campbell Scientific engineering tool
Figure 132.
10.10.1
DevConfig Terminal Tab
Serial Talk Through and Comms Watch
In the P: Serial Talk Through and W: Comms Watch modes, the timeout can
be changed from the default of 40 seconds to any value ranging from 1 to 86400
seconds (86400 seconds = 1 day).
When using options P or W in a terminal session, consider the following:
x
x
x
Concurrent terminal sessions are not allowed by the CR1000.
Opening a new terminal session will close the current terminal session.
The CR1000 will attempt to enter a terminal session when it receives nonPakBus characters on the nine-pin RS-232 port or CS I/O port, unless the
port is first opened with the SerialOpen() command.
If the CR1000 attempts to enter a terminal session on the nine-pin RS-232 port or
CS I/O port because of an incoming non-PakBus character, and that port was not
opened using the SerialOpen() command, any currently running terminal
function, including the comms watch, will immediately stop. So, in programs that
503
Section 10. Troubleshooting
frequently open and close a serial port, the probability is higher that a non-PakBus
character will arrive at the closed serial port, thus closing an existing talk-through
or comms watch session. If this occurs, the FileManager() setting to send comms
watch or sniffer to a file is immune to this problem.
10.11 Logs
Logs are meta data, usually about datalogger or software function. Logs, when
enabled, are available at the locations listed in the following table.
Table 134. Log Locations
Software Package
Usual Location of Logs
LoggerNet
C:\Campbellsci\LoggerNet\Logs
PC400
C:\Campbellsci\PC400\Logs
DevConfig
C:\Campbellsci\DevConfig\sys\cora\Logs
10.12 Troubleshooting — Data Recovery
In rare circumstances, exceptional efforts may be required to recover data that are
otherwise lost to conventional data-collection methods. Circumstances may
include the following:
x
Program control error
o
o
o
x
x
x
x
A CRBasic program was sent to the CR1000 without specifying that it
run on power-up. This is most likely to occur only while using the
Compile, Save and Send feature of older versions of CRBasic Editor.
A new program (even the same program) was inadvertently sent to the
CR1000 through the Connect client or Set Up client in LoggerNet.
The program was stopped through datalogger support software File
Control or LoggerLink software.
The CPU: drive was inadvertently formated.
A network peripheral (NL115, NL120, NL200, or NL240) was added to the
CR1000 when there was previously no network peripheral, and so forced the
CR1000 to reallocate memory.
A hardware failure, such as memory corruption, occurred.
Inserting or removing memory cards will generally do nothing to cause the
CR1000 to miss data. These events affect table definitions because they can
affect table size allocations, but they will not create a situation where data
recovery is necessary.
Data can usually be recovered using the Datalogger Data Recovery wizard
available in DevConfig (p. 111). Recovery is possible because data in memory is not
usually destroyed, only lost track of. So, the wizard recovers "data" from the
entire memory, whether or not that memory has been written to, or written to
recently.
Once you have run through the recovery procedure, consider the following:
If a CRD: drive (memory card) or a USB: drive (Campbell Scientific mass storage
device) has been removed since the data was originally stored, then the
Datalogger Data Recovery is run, the memory pointer will likely be in the wrong
location, so the recovered data will be corrupted. If this is the case, put the CRD:
504
Section 10. Troubleshooting
or USB: drive back in place and re-run the Datalogger Data Recovery wizard
before restarting the CRBasic program.
In any case, even when the recovery runs properly, the result will be that good
data is recovered mixed with sections of empty or old junk. With the entire data
dump in one file, you can sort through the good and the bad.
505
11. Glossary
11.1
Terms
Term. ac
See Vac (p. 532).
Term. accuracy
A measure of the correctness of a measurement. See also the appendix
Accuracy, Precision, and Resolution (p. 533).
Term. A-to-D
Analog-to-digital conversion. The process that translates analog voltage
levels to digital values.
Term. amperes (A)
Base unit for electric current. Used to quantify the capacity of a power source
or the requirements of a power-consuming device.
Term. analog
Data presented as continuously variable electrical signals.
Term. argument
Parameter (p. 523): part of a procedure (or command) definition.
Argument (p. 507): part of a procedure call (or command execution). An
argument is placed in a parameter. For example, in the CRBasic command
Battery(dest), dest is a parameter that defines what argument is to be put in
its place in a CRBasic program. If a variable named BattV is to hold the
result of the battery measurement made by Battery(), BattV is the argument
placed in dest. In the statement
Battery(BattV)
BattV is the argument.
Term. ASCII / ANSI
Reading List:
‡Term. ASCII / ANSI (p. 507)
‡ASCII / ANSI table (p. 637)
Abbreviation for American Standard Code for Information Interchange /
American National Standards Institute. An encoding scheme in which
numbers from 0-127 (ASCII) or 0-255 (ANSI) are used to represent predefined alphanumeric characters. Each number is usually stored and
transmitted as 8 binary digits (8 bits), resulting in 1 byte of storage per
character of text.
507
Section 11. Glossary
Term. asynchronous
The transmission of data between a transmitting and a receiving device
occurs as a series of zeros and ones. For the data to be "read" correctly, the
receiving device must begin reading at the proper point in the series. In
asynchronous communication, this coordination is accomplished by having
each character surrounded by one or more start and stop bits which designate
the beginning and ending points of the information (see synchronous (p. 530) ).
Indicates the sending and receiving devices are not synchronized using a
clock signal.
Term. AWG
AWG ("gauge") is the accepted unit when identifying wire diameters. Larger
AWG values indicate smaller cross-sectional diameter wires. Smaller AWG
values indicate large-diameter wires. For example, a 14 AWG wire is often
used for grounding because it can carry large currents. 22 AWG wire is often
used as sensor leads since only small currents are carried when measurements
are made.
Term. baud rate
The rate at which data are transmitted.
Term. beacon
A signal broadcasted to other devices in a PakBus® network to identify
"neighbor" devices. A beacon in a PakBus network ensures that all devices in
the network are aware of other devices that are viable. If configured to do so,
a clock-set command may be transmitted with the beacon. This function can
be used to synchronize the clocks of devices within the PakBus network. See
also PakBus (p. 522) and neighbor device (p. 521).
Term. binary
Describes data represented by a series of zeros and ones. Also describes the
state of a switch, either being on or off.
Term. BOOL8
A one-byte data type that holds eight bits (0 or 1) of information. BOOL8
uses less space than the 32 bit BOOLEAN data type.
Term. boolean
Name given a function, the result of which is either true or false.
Term. boolean data type
Typically used for flags and to represent conditions or hardware that have
only two states (true or false) such as flags and control ports.
508
Section 11. Glossary
Term. burst
Refers to a burst of measurements. Analogous to a burst of light, a burst of
measurements is intense, such that it features a series of measurements in
rapid succession, and is not continuous.
Term. calibration wizard
The calibration wizard facilitates the use of the CRBasic field calibration
instructions FieldCal() and FieldCalStrain(). It is found in LoggerNet (4.0
or higher) or RTDAQ.
Term. Callback
A name given to the process by which the CR1000 initiates
telecommunication with a PC running appropriate Campbell Scientific
datalogger support software (p. 654). Also known as "Initiate
Telecommunications."
Term. CardConvert software
A utility to retrieve CR1000 final-memory data from Compact Flash (CF)
cards and convert the data to ASCII or other useful formats.
Term. CD100
An optional enclosure mounted keyboard display for use with CR1000
dataloggers. See the appendix Keyboard Display — List (p. 651).
Term. CDM/CPI
CPI is a proprietary interface for communications between Campbell
Scientific dataloggers and Campbell Scientific CDM peripheral devices. It
consists of a physical layer definition and a data protocol. CDM devices are
similar to Campbell Scientific SDM devices in concept, but the use of the
CPI bus enables higher data-throughput rates and use of longer cables. CDM
devices require more power to operate in general than do SDM devices.
Term. CF
See CompactFlash (p. 510).
Term. code
A CRBasic program, or a portion of a program.
Term. Collect / Collect Now button
Button or command in datalogger support software that facilitates collectionon-demand of final-data memory. This feature is found in PC200W, PC400,
LoggerNet, and RTDAQ. software.
Term. COM port
COM is a generic name given to physical and virtual serial communication
ports.
509
Section 11. Glossary
Term. CompactFlash
CompactFlash® (CF) is a memory-card technology used in some Campbell
Scientific card-storage modules. CompactFlash® is a registered trademark of
the CompactFlash® Association.
Term. input/output instructions
Usually refers to a CRBasic command.
Term. command line
One line in a CRBasic program. Maximum length, even with the line
continuation characters <space> <underscore> ( _), is 512 characters. A
command line usually consists of one program statement, but it may consist
of mulitple program statements separated by a <colon> (:).
Term. compile
The software process of converting human-readable program code to binary
machine code. CR1000 user programs are compiled internally by the
CR1000 operating system.
Term. conditioned output
The output of a sensor after scaling factors are applied. See unconditioned
output (p. 531).
Term. connector
A connector is a device that allows one or more electron conduits (wires,
traces, leads, etc) to be connected or disconnected as a group. A connector
consists of two parts — male and female. For example, a common household
ac power receptacle is the female portion of a connector. The plug at the end
of a lamp power cord is the male portion of the connector. See terminal (p. 530).
Term. constant
A packet of CR1000 memory given an alpha-numeric name and assigned a
fixed number.
Term. control I/O
C terminals configured for controlling or monitoring a device.
Term. CoraScript
CoraScript is a command-line interpreter associated with LoggerNet
datalogger support software. Refer to the LoggerNet manual, available at
www.campbellsci.com, for more information.
510
Section 11. Glossary
Term. CPU
Central processing unit. The brains of the CR1000. Also refers to two the
following two memory areas:
o
o
CPU: memory drive
Memory used by the CPU to store table data.
Term. CR1000KD
An optional hand-held keyboard display for use with the CR1000 datalogger.
See the appendix Keyboard Display -- List (p. 651).
Term. cr
Carriage return
Term. CRBasic Editor Compile, Save and Send
CRBasic Editor menu command that compiles, saves, and sends the program
to the datalogger.
Term. CRD
An optional memory drive that resides on a memory card. See CompactFlash
(p. 510).
Term. CS I/O
Campbell Scientific proprietary input / output port. Also, the proprietary
serial communication protocol that occurs over the CS I/O port.
Term. CVI
Communication verification interval. The interval at which a PakBus®
device verifies the accessibility of neighbors in its neighbor list. If a neighbor
does not communicate for a period of time equal to 2.5 times the CVI, the
device will send up to four Hellos. If no response is received, the neighbor is
removed from the neighbor list. See the section PakBus — Overview (p. 88) for
more information.
Term. data cache
The data cache is a set of binary files kept on the hard disk of the computer
running the datalogger support software (p. 512). A binary file is created for
each table in each datalogger. These files mimic the storage areas in
datalogger memory, and by default are two times the size of the datalogger
storage area. When the software collects data from a CR1000, the data are
stored in the binary file for that CR1000. Various software functions retrieve
data from the data cache instead of the CR1000 directly. This allows the
simultaneous sharing of data among software functions.
Similar in function to a CR1000 final-memory data tables, the binary files for
the data cache are set up by default as ring memory (p. 526).
511
Section 11. Glossary
Term. datalogger support software
Campbell Scientific software that includes at least the following functions:
o
o
o
o
Datalogger telecommunications
Downloading programs
Clock setting
Retrieval of measurement data
See Datalogger Support Software — Overview (p. 95) and the appendix
Datalogger Support Software — List (p. 654) for more information.
Term. data point
A data value which is sent to final-data memory (p. 515) as the result of a dataoutput processing instruction (p. 512). Strings of data points output at the same
time make up a record in a data table.
Term. data table
A concept that describes how data are organized in CR1000 memory, or in
files that result from collecting data in CR1000 memory. The fundamental
data table is created by the CRBasic program as a result of the DataTable()
instruction and resides in binary form in main-memory SRAM. See the table
CR1000 Memory Allocation (p. 371). The data table structure also resides in the
data cache (p. 511), in discrete data files on the CPU:, USR:, CRD:, and USB:
memory drives, and in binary or ASCII files that result from collecting finaldata memory with datalogger support software (p. 512).
Term. data-output interval
Alias: output interval
The interval between each write of a record (p. 525) to a final-data memory data
table.
Term. data-output-processing instructions
CRBasic instructions that process data values for eventual output to final-data
memory. Examples of output-processing instructions include Totalize(),
Maximize(), Minimize(), and Average(). Data sources for these instructions
are values or strings in variable memory. The results of intermediate
calculations are stored in data-output-processing memory (p. 512) to await the
output trigger. The ultimate destination of data generated by data-outputprocessing instructions is usually final-data memory, but it may be diverted to
variable memory by the CRBasic program for further processing. The
transfer of processed summaries to final-data memory takes place when the
Trigger argument in the DataTable() instruction is set to True.
Term. data-output-processing memory
SRAM memory automatically allocated for intermediate calculations
performed by CRBasic data-output-processing instructions. Data-outputprocessing memory cannot be monitored. See section Processing for Output
to Final-Data Memory (p. 542) for a list of instructions that use Data-output512
Section 11. Glossary
processing memory.
Term. dc
See Vdc (p. 532).
Term. DCE
Data Communication Equipment. While the term has much wider meaning,
in the limited context of practical use with the CR1000, it denotes the pin
configuration, gender, and function of an RS-232 port. The RS-232 port on
the CR1000 is DCE. Interfacing a DCE device to a DCE device requires a
null-modem cable. See Term. DTE (p. 514).
Term. desiccant
A hygroscopic material that absorbs water vapor from the surrounding air.
When placed in a sealed enclosure, such as a datalogger enclosure, it prevents
condensation.
Term. DevConfig software
Device Configuration Utility (p. 111), available with LoggerNet, RTDAQ,
PC400, or at www.campbellsci.com/downloads
(http://www.campbellsci.com/downloads).
Term. DHCP
Dynamic Host Configuration Protocol. A TCP/IP application protocol.
Term. differential
A sensor or measurement terminal wherein the analog voltage signal is
carried on two leads. The phenomenon measured is proportional to the
difference in voltage between the two leads.
Term. Dim
A CRBasic command for declaring and dimensioning variables. Variables
declared with Dim remain hidden during datalogger operations.
Term. dimension
Verb. To code a CRBasic program for a variable array as shown in the
following examples:
o
o
o
DIM example(3) creates the three variables example(1), example(2), and
example(3).
DIM example(3,3) creates nine variables.
DIM example(3,3,3) creates 27 variables.
Term. DNS
Domain name system. A TCP/IP application protocol.
513
Section 11. Glossary
Term. DTE
Data Terminal Equipment. While the term has much wider meaning, in the
limited context of practical use with the CR1000, it denotes the pin
configuration, gender, and function of an RS-232 port. The RS-232 port on
the CR1000 is DCE. Attachment of a null-modem cable to a DCE device
effectively converts it to a DTE device. See Term. DCE (p. 513).
Term. duplex
A serial communication protocol. Serial communications can be simplex,
half-duplex, or full-duplex.
Reading list: simplex (p. 528), duplex (p. 248), half-duplex (p. 517), and full-duplex
(p. 516).
Term. duty cycle
The percentage of available time a feature is in an active state. For example,
if the CR1000 is programmed with 1 second scan interval, but the program
completes after only 100 millisecond, the program can be said to have a 10%
duty cycle.
Term. earth ground
A grounding rod or other suitable device that electrically ties a system or
device to the earth. Earth ground is a sink for electrical transients and
possibly damaging potentials, such as those produced by a nearby lightning
strike. Earth ground is the preferred reference potential for analog voltage
measurements. Note that most objects have a "an electrical potential" and the
potential at different places on the earth — even a few meters away — may
be different.
Term. engineering units
Units that explicitly describe phenomena, as opposed to, for example, the
CR1000 base analog-measurement unit of milliVolts.
Term. ESD
Electrostatic discharge
Term. ESS
Environmental Sensor Station
Term. excitation
Application of a precise voltage, usually to a resistive bridge circuit.
Term. execution interval
See scan interval (p. 526).
514
Section 11. Glossary
Term. execution time
Time required to execute an instruction or group of instructions. If the
execution time of a program exceeds the Scan() Interval, the program is
executed less frequently than programmed and the Status table SkippedScan
(p. 487) register will increment.
Term. expression
A series of words, operators, or numbers that produce a value or result.
Term. FFT
Fast Fourier Transform. A technique for analyzing frequency-spectrum data.
Term. File Control
File Control is a feature of LoggerNet, PC400 and RTDAQ (p. 95)
datalogger support software. It provides a view of the CR1000 file
system and a menu of file management commands:
Delete facilitates deletion of a specified file
Send facilitates transfer of a file (typically a CRBasic program file) from
PC memory to CR1000 memory.
Retrieve facilitates collection of files viewed in File Control. If
collecting a data file from a CF card with Retrieve, first stop the
CR1000 program or data corruption may result.
Format formats the selected CR1000 memory device. All files,
including data, on the device will be erased.
Term. File Retrieval tab
A feature of LoggerNet Setup Screen. In the Setup Screen network map
(Entire Network), click on a CR1000 datalogger node. The File Retieval tab
should be one of several tabs presented at the right of the screen.
Term. fill and stop memory
A memory configuration for data tables forcing a data table to stop accepting
data when full.
Term. final-data memory
The portion of CR1000 SRAM memory allocated for storing data tables with
output arrays. Once data are written to final-data memory, they cannot be
changed but only overwritten when they become the oldest data. Final-data
memory is configured as ring memory (p. 526) by default, with new data
overwriting the oldest data.
Term. final-memory data
Data that resides in final-data memory.
515
Section 11. Glossary
Term. Flash
A type of memory media that does not require battery backup. Flash
memory, however, has a lifetime based on the number of writes to it. The
more frequently data are written, the shorter the life expectancy.
Term. FLOAT
Four-byte floating-point data type. Default CR1000 data type for Public or
Dim variables. Same format as IEEE4.
Term. fN1
fN1 or Fnotch. First notch frequency. A notch, when referring to digital signal
processing (DSP), is a region in the frequency response at which frequencies
input into the filter are highly attenuated or 'notched out.' Signals input into
the filter at fN1 are completely eliminated, whereas frequencies near the
notch are greatly attenuated but not completely filtered out. A more technical
term is transmission zero,or zero signal transmission through the filter at the
given frequency.
Term. FP2
Two-byte floating-point data type. Default CR1000 data type for stored data.
While IEEE four-byte floating point is used for variables and internal
calculations, FP2 is adequate for most stored data. FP2 provides three or four
significant digits of resolution, and requires half the memory as IEEE4.
Term. FTP
File Transfer Protocol. A TCP/IP application protocol.
Term. full-duplex
A serial communication protocol. Simultaneous bi-directional
communications. Communications between a CR1000 serial port and a PC is
typically full duplex.
Reading list: simplex (p. 528), duplex (p. 248), half-duplex (p. 517), and full-duplex
(p. 516).
Term. frequency domain
Frequency domain describes data graphed on an X-Y plot with frequency as
the X axis. VSPECT (p. 532) vibrating-wire data are in the frequency domain.
Term. frequency response
Sample rate is how often an instrument reports a result at its output;
frequency response is how well an instrument responds to fast fluctuations on
its input. By way of example, sampling a large gage thermocouple at 1 kHz
will give a high sample rate but does not ensure the measurement has a high
frequency response. A fine-wire thermocouple, which changes output
quickly with changes in temperature, is more likely to have a high frequency
response.
516
Section 11. Glossary
Term. garbage
The refuse of the data communication world. When data are sent or received
incorrectly (there are numerous reasons why this happens), a string of invalid,
meaningless characters (garbage) often results. Two common causes are: 1) a
baud-rate mismatch and 2) synchronous data being sent to an asynchronous
device and vice versa.
Term. global variable
A variable available for use throughout a CRBasic program. The term is
usually used in connection with subroutines, differentiating global variables
(those declared using Public or Dim) from local variables, which are
declared in the Sub() and Function() instructions.
Term. ground
Being or related to an electrical potential of 0 volts.
Term. half-duplex
A serial communication protocol. Bi-directional, but not simultaneous,
communications. SDI-12 is a half-duplex protocol.
Reading list: simplex (p. 528), duplex (p. 248), half-duplex (p. 517), and full-duplex
(p. 516).
Term. handshake, handshaking
The exchange of predetermined information between two devices to assure
each that it is connected to the other. When not used as a clock line, the
CLK/HS (pin 7) line in the datalogger CS I/O port is primarily used to detect
the presence or absence of peripherals.
Term. hello exchange
The process of verifying a node as a neighbor. See section PakBus —
Overview (p. 88).
Term. hertz (Hz)
SI unit of frequency. Cycles or pulses per second.
Term. HTML
Hypertext Markup Language. Programming language used for the creation
of web pages.
Term. HTTP
Hypertext Transfer Protocol. A TCP/IP application protocol.
Term. IEEE4
Four-byte, floating-point data type. IEEE Standard 754. Same format as
Float.
517
Section 11. Glossary
Term. Include file
a file containing CRBasic code to be included at the end of the current
CRBasic program, or it can be run as the default program. See Include File
Name setting (p. 603).
Term. INF
A data word indicating the result of a function is infinite or undefined.
Term. initiate telecommunication
A name given to a processes by which the CR1000 initiates
telecommunications with a PC running LoggerNet. Also known as Callback
(p. 509).
Term. input/output instructions
Used to initiate measurements and store the results in input storage or to set
or read control/logic ports.
Term. input/output instructions
Usually refers to a CRBasic command.
Term. integer
A number written without a fractional or decimal component. 15 and 7956
are integers; 1.5 and 79.56 are not.
Term. intermediate memory
See data-output-processing memory (p. 512).
Term. IP
Internet Protocol. A TCP/IP internet protocol.
Term. IP address
A unique address for a device on the internet.
Term. IP trace
Function associated with IP data transmissions. IP trace information was
originally accessed through the CRBasic instruction IPTrace() (p. 289) and
stored in a string variable. Files Manager setting (p. 603) is now modified to
allow for creation of a file on a CR1000 memory drive, such as USR:, to store
information in ring memory.
Term. isolation
Hardwire telecommunication devices and cables can serve as alternate paths
to earth ground and entry points into the CR1000 for electromagnetic noise.
Alternate paths to ground and electromagnetic noise can cause measurement
errors. Using opto-couplers in a connecting device allows telecommunication
518
Section 11. Glossary
signals to pass, but breaks alternate ground paths and may filter some
electromagnetic noise. Campbell Scientific offers optically isolated RS-232
to CS I/O interfaces as a CR1000 accessory for use on the CS I/O port. See
the appendix Serial I/O Modules List (p. 646).
Term. JSON
Java Script Object Notation. A data file format available through the
CR1000 or LoggerNet.
Term. KEEP memory
Non-volatile memory that preserves some registers (p. 603) through a CR1000
reset that occurs due to power-up and program start-up. Examples include
PakBus address, station name, beacon intervals, neighbor lists, routing table,
and communication timeouts.
Term. keyboard display
The CR1000KD is an optional keyboard display for use as a peripheral with
the CR1000 datalogger. See appendix Keyboard Display — List (p. 651) for
other compatible keyboard displays.
Term. leaf node
A PakBus node at the end of a branch. When in this mode, the CR1000 is not
able to forward packets from one of its communication ports to another. It
will not maintain a list of neighbors, but it still communicates with other
PakBus dataloggers and wireless sensors. It cannot be used as a means of
reaching (routing to) other dataloggers.
Term. lf
Line feed. Often associated with carriage return (<cr>). <cr><lf>.
Term. local variable
A variable available for use only by the subroutine in which it is declared.
The term differentiates local variables, which are declared in the Sub() and
Function() instructions, from global variables, which are declared using
Public or Dim.
Term. LONG
Data type used when declaring integers.
Term. loop
A series of instructions in a CRBasic program that are repeated a the
programmed number of times. The loop ends with an end instruction.
Term. loop counter
Increments by one with each pass through a loop.
519
Section 11. Glossary
Term. mains power
the national power grid
Term. manually initiated
Initiated by the user, usually with a CR1000KD Keyboard Display (p. 651), as
opposed to occurring under program control.
Term. mass storage device
USB: "thumb" drive. See appendix Data Storage Devices (p. 653).
Term. MD5 digest
16 byte checksum of the TCP/IP VTP configuration.
Term. milli
The SI prefix denoting 1/1000 of a base SI unit.
Term. Modbus
Communication protocol published by Modicon in 1979 for use in
programmable logic controllers (PLCs). See section Modbus (p. 91).
Term. modem/terminal
Any device that has the following:
o
o
Ability to raise the CR1000 ring line or be used with an optically isolated
interface (see the appendix CS I/O Serial Interfaces (p. 652) ) to raise the
ring line and put the CR1000 in the telecommunication command state.
Asynchronous serial communication port that can be configured to
communicate with the CR1000.
Term. modulo divide
A math operation. Result equals the remainder after a division.
Term. MSB
Most significant bit (the leading bit). See the appendix Endianness (p. 643).
Term. multi-meter
An inexpensive and readily available device useful in troubleshooting dataacquisition system faults.
Term. multiplier
A term, often a parameter in a CRBasic measurement instruction, that
designates the slope (aka, scaling factor or gain) in a linear function. For
example, when converting °C to °F, the equation is °F = °C*1.8 + 32. The
factor 1.8 is the multiplier. See Term. offset (p. 521).
520
Section 11. Glossary
Term. mV
The SI abbreviation for millivolts.
Term. NAN
Not a number. A data word indicating a measurement or processing error.
Voltage over-range, SDI-12 sensor error, and undefined mathematical results
can produce NAN. See the section NAN and ±INF (p. 482).
Term. neighbor device
Device in a PakBus network that communicate directly with a device without
being routed through an intermediate device. See PakBus (p. 522).
Term. NIST
National Institute of Standards and Technology
Term. node
Devices in a network — usually a PakBus network. The communication
server dials through, or communicates with, a node. Nodes are organized as a
hierarchy with all nodes accessed by the same device (parent node) entered as
child nodes. A node can be both a parent and a child. See PakBus —
Overview (p. 88).
Term. NSEC
Eight-byte data type divided up as four bytes of seconds since 1990 and four
bytes of nanoseconds into the second. See Data Type (p. 131, p. 130) tables.
Term. null-modem
A device, usually a multi-conductor cable, which converts an RS-232 port
from DCE to DTE or from DTE to DCE.
Term. Numeric Monitor
A digital monitor in datalogger support software (p. 654) or in a keyboard
display.
Term. offset
A term, often a parameter in a CRBasic measurement instruction, that
designates the y-intercept (aka, shifting factor or zeroing factor) in a linear
function. For example, when converting °C to °F, the equation is °F =
°C*1.8 + 32. The factor 32 is the offset. See Term. multiplier (p. 520).
Term. ohm
The unit of resistance. Symbol is the Greek letter Omega (ȍȍHTXDOV
the ratio of 1.0 volt divided by 1.0 ampere.
521
Section 11. Glossary
Term. Ohm's Law
Describes the relationship of current and resistance to voltage. Voltage equals
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Term. on-line data transfer
Routine transfer of data to a peripheral left on-site. Transfer is controlled by
the program entered in the datalogger.
Term. operating system
The operating system (also known as "firmware") is a set of instructions that
controls the basic functions of the CR1000 and enables the use of user written
CRBasic programs. The operating system is preloaded into the CR1000 at
the factory but can be re-loaded or upgraded by you using Device
Configuration Utility (p. 111) software. The most recent CR1000 operating
system .obj file is available at www.campbellsci.com/downloads
(http://www.campbellsci.com/downloads).
Term. output
A loosely applied term. Denotes a) the information carrier generated by an
electronic sensor, b) the transfer of data from variable memory to final-data
memory, or c) the transfer of electric power from the CR1000 or a peripheral
to another device.
Term. output array
A string of data values output to final-data memory. Output occurs when the
data table output trigger is True.
Term. output interval
See data-output-interval (p. 512).
Term. output-processing instructions
See data-output-processing instructions (p. 512).
Term. output-processing memory
See data-output-processing memory (p. 512).
Term. PakBus
A proprietary telecommunication protocol similar to IP (p. 518) protocol
developed by Campbell Scientific to facilitate communications between
Campbell Scientific instrumentation. See PakBus — Overview (p. 88) for more
information.
Term. PakBusGraph software
Shows the relationship of various nodes in a PakBus network and allows for
monitoring and adjustment of some registers (p. 525) in each node. A PakBus
522
Section 11. Glossary
node is typically a Campbell Scientific datalogger, a PC, or a
telecommunication device. See section Datalogger Support Software (p. 450).
Term. parameter
Parameter (p. 523): part of a procedure (or command) definition.
Argument (p. 507): part of a procedure call (or command execution). An
argument is placed in a parameter. For example, in the CRBasic command
Battery(dest), dest is a parameter that defines what argument is to be put in
its place in a CRBasic program. If a variable named BattV is to hold the
result of the battery measurement made by Battery(), BattV is the argument
placed in dest. In the statement
Battery(BattV)
BattV is the argument.
Term. period average
A measurement technique using a high-frequency digital clock to measure
time differences between signal transitions. Sensors commonly measured
with period average include water-content reflectometers.
Term. peripheral
Any device designed for use with the CR1000 (or another Campbell
Scientific datalogger). A peripheral requires the CR1000 to operate.
Peripherals include measurement, control (p. 85), and data-retrieval and
telecommunication (p. 651) modules.
Term. ping
A software utility that attempts to contact another device in a network. See
section PakBus — Overview (p. 88) and sections Ping (PakBus) (p. 398) and Ping
(IP) (p. 295).
Term. ping
A CRBasic program execution mode wherein instructions are evaluated in
groups of like instructions, with a set group prioritization. More information
is available in section Pipeline Mode (p. 152). See Term. sequential mode (p.
527).
Term. Poisson ratio
A ratio used in strain measurements. Equal to transverse strain divided by
extension strain as follows:
v = -İtrans İaxial).
Term. precision
A measure of the repeatability of a measurement. Also see the appendix
Accuracy, Precision, and Resolution (p. 533).
523
Section 11. Glossary
Term. PreserveVariables
CRBasic instruction that protects Public variables from being erased when a
program is recompiled.
Term. print device
Any device capable of receiving output over pin 6 (the PE line) in a receiveonly mode. Printers, "dumb" terminals, and computers in a terminal mode fall
in this category.
Term. print peripheral
See print device (p. 524).
Term. processing instructions
CRBasic instructions used to further process input-data values and return the
result to a variable where it can be accessed for output processing.
Arithmetic and transcendental functions are included. See appendix
Processing and Math Instructions (p. 563).
Term. program control instructions
Modify the execution sequence of CRBasic instructions. Also used to set or
clear flags. See section PLC Control — Overview (p. 74).
Term. program statement
A complete program command construct confined to one command line or to
multiple command lines merged with the line continuation characters
<space><underscore> ( _). A command line, even with line continuation,
cannot exceed 512 characters.
Term. Program Send command
Program Send is a feature of datalogger support software (p. 95). Command
wording varies among software according to the following table:
Table 135. Program Send Command
Software
Command
Command Location
LoggerNet
Send New...
Connect screen
PC400
Send Program
Clock/Program tab
RTDAQ
Send Program
Clock/Program tab
PC200W
Send Program
Clock/Program tab
Term. Public
A CRBasic command for declaring and dimensioning variables. Variables
declared with Public can be monitored during datalogger operation. See
Term. Dim (p. 513).
524
Section 11. Glossary
Term. pulse
An electrical signal characterized by a rapid increase in voltage follow by a
short plateau and a rapid voltage decrease.
Term. record
A record is a complete line of data in a data table or data file. All data in a
record share a common time stamp.
Term. regulator
A setting, a Status table element, or a DataTableInformation table element.
Term. regulator
A device for conditioning an electrical power source. Campbell Scientific
regulators typically condition ac or dc voltages greater than 16 Vdc to about
14 Vdc.
Term. Reset Tables command
Reset Tables command resets data tables configured for fill and stop.
Location of the command varies among datalogger support software
according to the following:
LoggerNet — Connect Screen | Station Status tab | Table Fill Times tab
| Reset Tables
PC400 — command sequence: Datalogger | Station Status | Table Fill
Times | Reset Tables
RTDAQ — command sequence: Datalogger | Station Status | Table Fill
Times | Reset Tables
PC200W — command sequence: Datalogger | Station Status | Table
Fill Times | Reset Tables
Term. resistance
A feature of an electronic circuit that impedes or redirects the flow of
electrons through the circuit.
Term. resistor
A device that provides a known quantity of resistance.
Term. resolution
A measure of the fineness of a measurement. See also Accuracy, Precision,
and Resolution (p. 533).
Term. ring line
Ring line is pulled high by an external device to notify the CR1000 to
commence RS-232 communications. Ring line is pin 3 of a DCE (p. 513) RS232 port.
525
Section 11. Glossary
Term. ring memory
A memory configuration that allows the oldest data to be overwritten with the
newest data. This is the default setting for final-memory data tables.
Term. ringing
Oscillation of sensor output (voltage or current) that occurs when sensor
excitation causes parasitic capacitances and inductances to resonate.
Term. RMS
Root-mean square, or quadratic mean. A measure of the magnitude of wave
or other varying quantities around zero.
Term. router
Device configured as a router is able to forward PakBus packets from one
port to another. To perform its routing duties, a CR1000 configured as a
router maintains its own list of neighbors and sends this list to other routers in
the PakBus network. It also obtains and receives neighbor lists from other
routers.
Term. RS-232
Recommended Standard 232. A loose standard defining how two computing
devices can communicate with each other. The implementation of RS-232 in
Campbell Scientific dataloggers to PC communications is quite rigid, but
transparent to most users. Features in the CR1000 that implement RS-232
communication with smart sensors are flexible.
Term. sample rate
The rate at which measurements are made by the CR1000. The measurement
sample rate is of interest when considering the effect of time skew, or how
close in time are a series of measurements, or how close a time stamp on a
measurement is to the true time the phenomenon being measured occurred. A
'maximum sample rate' is the rate at which a measurement can repeatedly be
made by a single CRBasic instruction.
Sample rate is how often an instrument reports a result at its output;
frequency response is how well an instrument responds to fast fluctuations on
its input. By way of example, sampling a large gage thermocouple at