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.com or by telephoning 435227-9000 (USA). 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 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
•
Prior to performing site or installation work, obtain required approvals and permits. Comply with all governing structure-height
regulations, such as those of the FAA in the USA.
•
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.
•
•
•
Read all applicable instructions carefully and understand procedures thoroughly before beginning work.
•
Use only manufacturer recommended parts, materials, and tools.
Wear a hardhat and eye protection, and take other appropriate safety precautions while working on or around tripods and towers.
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.
Utility and Electrical
•
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.
•
Maintain a distance of at least one-and-one-half times structure height, or 20 feet, or the distance required by applicable law,
whichever is greater, between overhead utility lines and the structure (tripod, tower, attachments, or tools).
•
•
Prior to performing site or installation work, inform all utility companies and have all underground utilities marked.
Comply with all electrical codes. Electrical equipment and related grounding devices should be installed by a licensed and qualified
electrician.
Elevated Work and Weather
•
•
•
•
Exercise extreme caution when performing elevated work.
Use appropriate equipment and safety practices.
During installation and maintenance, keep tower and tripod sites clear of un-trained or non-essential personnel. Take precautions to
prevent elevated tools and objects from dropping.
Do not perform any work in inclement weather, including wind, rain, snow, lightning, etc.
Maintenance
•
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.
•
Periodically (at least yearly) check electrical ground connections.
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:
•
•
•
Protect from over-voltage.
Protect from water (see "Datalogger Enclosures" on page 59).
Protect from ESD (see "Electrostatic Discharge and Lightning Protection" on page 61).
IMPORTANT: Note the following about the internal battery:
•
•
•
When primary power is continuously connected to the datalogger, the battery will last up to 10 years or more.
When primary power is NOT connected to the datalogger, the battery will last about three years.
See "Internal Battery" on page 59 for more information.
IMPORTANT: Maintain a level of calibration appropriate to the application. Campbell Scientific recommends factory recalibration of the
datalogger every three years.
WHILE EVERY ATTEMPT IS MADE TO EMBODY THE HIGHEST DEGREE OF SAFETY IN ALL CAMPBELL SCIENTIFIC PRODUCTS, THE
CUSTOMER 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.
Warranty
The datalogger is warranted for three (3) years subject to this limited warranty: https://www.campbellsci.com/terms#warranty.
Acknowledgements
lwIP
Copyright (c) 2001-2004 Swedish Institute of Computer Science.
All rights reserved.
Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following
conditions are met:
1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following
disclaimer.
2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following
disclaimer in the documentation and/or other materials provided with the distribution.
3. The name of the author may not be used to endorse or promote products derived from this software without specific
prior written permission.
THIS SOFTWARE IS PROVIDED BY THE AUTHOR “AS IS” AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING,
BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Table of Contents
DATA ACQUISITION SYSTEM COMPONENTS ............................................................................................ 1
Sensors.............................................................................................................................................. 2
Supported Sensor Types ................................................................................................................ 2
The CR1000X Datalogger .................................................................................................................. 2
Components ................................................................................................................................... 3
Operations ...................................................................................................................................... 3
Programs ........................................................................................................................................ 3
WIRING PANEL AND TERMINAL FUNCTIONS............................................................................................. 4
Power Input ........................................................................................................................................ 5
Powering A Datalogger with a Vehicle ............................................................................................ 6
Power LED Indicator ....................................................................................................................... 6
Power Output ..................................................................................................................................... 6
Grounds ............................................................................................................................................. 7
Communication Ports ......................................................................................................................... 8
USB Port ........................................................................................................................................ 9
Ethernet Port .................................................................................................................................. 9
C Terminals for Communications .................................................................................................... 9
CS I/O Port ................................................................................................................................... 10
RS-232/CPI Port ........................................................................................................................... 10
Programmable Logic Control ............................................................................................................ 10
Example: Turn Modem on for 10 Minutes Hourly .......................................................................... 11
SETTING UP THE DATALOGGER........................................................................................................... 12
Setting up Communications with the Datalogger .............................................................................. 12
USB or RS-232 Communications .................................................................................................. 12
Virtual Ethernet over USB (RNDIS)............................................................................................... 13
Ethernet Communications ............................................................................................................ 14
Testing Communication and Completing EZ Setup .......................................................................... 16
Connecting the Datalogger to a Computer ....................................................................................... 17
Creating a Program in Short Cut ...................................................................................................... 17
Sending a Program to the Datalogger .............................................................................................. 19
Sending a Program Using Datalogger Support Software .............................................................. 20
WORKING WITH DATA ........................................................................................................................ 21
Monitoring Data ................................................................................................................................ 21
Collecting Data................................................................................................................................. 22
Collecting Data Using LoggerNet .................................................................................................. 22
Collecting Data Using PC200W or PC400W ................................................................................. 22
Viewing Historic Data ....................................................................................................................... 22
About Data Tables ........................................................................................................................... 23
Table Definitions ........................................................................................................................... 23
Creating Data Tables in a Program .................................................................................................. 25
MEMORY AND DATA STORAGE ............................................................................................................ 26
Memory Allocation ........................................................................................................................... 26
SRAM .............................................................................................................................................. 26
Data Storage ................................................................................................................................ 27
USR Drive .................................................................................................................................... 27
Flash Memory .................................................................................................................................. 28
Serial Flash Memory ........................................................................................................................ 28
CPU Drive .................................................................................................................................... 28
MicroSD (CRD: Drive) Storage......................................................................................................... 28
Formatting MicroSD Cards ........................................................................................................... 29
MicroSD Card Precautions ........................................................................................................... 29
MicroSD LED Indicator ................................................................................................................. 29
File Management via Powerup.ini .................................................................................................... 30
Syntax .......................................................................................................................................... 30
Example Powerup.ini Programs .................................................................................................... 31
MEASUREMENTS ............................................................................................................................... 32
Voltage Measurements .................................................................................................................... 32
Single-Ended Measurements........................................................................................................ 33
Differential Measurements ............................................................................................................ 33
Current-Loop Measurements ........................................................................................................... 33
Example Current-Loop Measurement Connections....................................................................... 34
Resistance Measurements ............................................................................................................... 35
Resistance Measurements with Voltage Excitation ....................................................................... 35
Strain Measurements.................................................................................................................... 38
Ac Excitation ................................................................................................................................. 39
Accuracy for Resistance Measurements ....................................................................................... 40
Thermocouple Measurements .......................................................................................................... 40
Period-Averaging Measurements ..................................................................................................... 41
Pulse Measurements ....................................................................................................................... 41
Low-Level Ac Measurements ........................................................................................................ 42
High Frequency Measurements .................................................................................................... 43
Switch-Closure and Open-Collector Measurements...................................................................... 43
Edge Timing and Edge Counting .................................................................................................. 44
Pulse Measurement Tips .............................................................................................................. 45
Vibrating Wire Measurements .......................................................................................................... 46
VSPECT ....................................................................................................................................... 46
COMMUNICATION PROTOCOLS ............................................................................................................ 47
General Serial Communications ....................................................................................................... 47
Modbus Communications ................................................................................................................. 48
Internet Communications ................................................................................................................. 49
IP Address .................................................................................................................................... 49
HTTPS.......................................................................................................................................... 49
DNP3 Communications .................................................................................................................... 49
PakBus Communications ................................................................................................................. 50
SDI-12 Communications .................................................................................................................. 50
SDI-12 Transparent Mode ............................................................................................................ 51
SDI-12 Programmed Mode/Recorder Mode .................................................................................. 52
Programming the Datalogger to Act as an SDI-12 Sensor ............................................................ 53
SDI-12 Power Considerations ....................................................................................................... 53
Serial Peripheral Interface (SPI) and I2C.......................................................................................... 54
MAINTAINING YOUR DATALOGGER ...................................................................................................... 55
Datalogger Calibration ..................................................................................................................... 55
About Background Calibration ...................................................................................................... 55
Datalogger Security.......................................................................................................................... 56
Security Codes ............................................................................................................................. 57
Creating a .csipasswd File ............................................................................................................ 57
Datalogger Enclosures ..................................................................................................................... 59
Internal Battery................................................................................................................................. 59
Internal Lithium Battery Specifications .......................................................................................... 60
Replacing the Internal Battery ....................................................................................................... 60
Electrostatic Discharge and Lightning Protection.............................................................................. 61
Power Budgeting .............................................................................................................................. 62
Updating the Operating System ....................................................................................................... 62
Sending an Operating System to a Local Datalogger .................................................................... 63
Sending an Operating System to a Remote Datalogger ................................................................ 63
TIPS AND TROUBLESHOOTING............................................................................................................. 65
Checking Station Status ................................................................................................................... 65
Viewing Station Status .................................................................................................................. 66
Watchdog Errors........................................................................................................................... 66
Results for Last Program Compiled .............................................................................................. 66
Skipped Scans.............................................................................................................................. 67
Skipped Records .......................................................................................................................... 67
Variable Out of Bounds ................................................................................................................. 67
Battery Voltage ............................................................................................................................. 67
Understanding NAN and INF Occurrences ....................................................................................... 67
Time Keeping ................................................................................................................................... 68
Clock Best Practices ..................................................................................................................... 68
Time Stamps ................................................................................................................................ 68
Avoiding Time Skew ..................................................................................................................... 68
CRBasic Program Errors .................................................................................................................. 69
Program Does Not Compile .......................................................................................................... 69
Program Compiles but Does Not Run Correctly ............................................................................ 69
Resetting the Datalogger.................................................................................................................. 70
Processor Reset ........................................................................................................................... 70
Program Send Reset .................................................................................................................... 70
Manual Data Table Reset ............................................................................................................. 70
Formatting Drives ......................................................................................................................... 70
Full Memory Reset........................................................................................................................ 71
Troubleshooting Power Supplies ...................................................................................................... 71
Minimizing Ground Loop Errors ........................................................................................................ 71
Improving Voltage Measurement Quality .......................................................................................... 73
Deciding Between Single-Ended or Differential Measurements .................................................... 73
Minimizing Ground Potential Differences ...................................................................................... 74
Detecting Open Inputs .................................................................................................................. 75
Minimizing Power-Related Artifacts .............................................................................................. 75
Filtering to Reduce Measurement Noise ....................................................................................... 76
Minimizing Settling Errors ............................................................................................................. 77
Factors Affecting Accuracy ........................................................................................................... 79
Minimizing Offset Voltages ........................................................................................................... 80
Field Calibration ............................................................................................................................... 83
File System Error Codes .................................................................................................................. 83
File Name and Resource Errors ....................................................................................................... 84
Background Calibration Errors ......................................................................................................... 84
SPECIFICATIONS ............................................................................................................................... 85
System Specifications ...................................................................................................................... 85
Physical Specifications ..................................................................................................................... 85
Power Requirements........................................................................................................................ 85
Ground Specifications ...................................................................................................................... 86
Power Output Specifications ............................................................................................................ 87
Analog Measurements Specifications............................................................................................... 88
Voltage Measurements ................................................................................................................. 88
Resistance Measurements Specifications ..................................................................................... 90
Period-Averaging Measurements Specifications ........................................................................... 90
Current-Loop Measurements Specifications ..................................................................................... 90
Pulse Measurements Specifications ................................................................................................. 91
Switch Closure Input ..................................................................................................................... 91
High-Frequency Input ................................................................................................................... 91
Low-Level Ac Input ....................................................................................................................... 91
Digital Input/Output Specifications.................................................................................................... 91
Switch Closure Input ..................................................................................................................... 92
High-Frequency Input ................................................................................................................... 92
Edge Timing ................................................................................................................................. 92
Pulse-Width Modulation ................................................................................................................ 92
Communications Specifications ....................................................................................................... 92
GLOSSARY ....................................................................................................................................... 94
INDEX ............................................................................................................................................ 113
Data Acquisition System Components
A basic data acquisition system consists of sensors, measurement hardware, and a computer with
programmable software. The objective of a data acquisition system should be high accuracy, high
precision, and resolution as high as appropriate for a given application.
The concept of a data acquisition system is illustrated in the following figure.
Following is a list of typical data acquisition system components:
• Sensors - Electronic sensors convert the state of a phenomenon to an electrical signal (see
"Sensors" on page 2 for more information).
• Datalogger - The datalogger 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 computer by way of an external
storage device or a communication link.
• Data Retrieval and Communications - Data are copied (not moved) from the datalogger, usually
to a computer, by one or more methods using datalogger support software. Most communication
options are bi-directional, which allows programs and settings to be sent to the datalogger. For
more information, see "Sending a Program to the Datalogger" on page 19.
• Datalogger Support Software - Software retrieves data, sends programs, and sets settings. The
software manages the communication link and has options for data display.
• Programmable Logic Control - Some data acquisition systems require the control of external
devices to facilitate a measurement or to control a device based on measurements. This
datalogger is adept at programmable logic control. See "Programmable Logic Control" on
page 10 for more information.
• Measurement and Control Peripherals - Sometimes, system requirements exceed the capacity of
the datalogger. The excess can usually be handled by addition of input and output expansion
modules.
Data Acquisition System Components
1
Sensors
Sensors transduce phenomena into measurable electrical forms by modulating voltage, current,
resistance, status, or pulse output signals. Suitable sensors do this with accuracy and precision. Smart
sensors have internal measurement and processing components and simply output a digital value in
binary, hexadecimal, or ASCII character form.
Most electronic sensors, regardless of manufacturer, will interface with the datalogger. Some sensors
require external signal conditioning. The performance of some sensors is enhanced with specialized
input modules. The datalogger, sometimes with the assistance of various peripheral devices, can
measure or read nearly all electronic sensor output types.
The following list may not be comprehensive. A library of sensor manuals and application notes are
available at www.campbellsci.com/support to assist in measuring many sensor types.
SUPPORTED SENSOR TYPES
• Analog
o Voltage
o Current
o Strain
o Thermocouples
o Resistive bridges
• Pulse
o High frequency
o Switch-closure
o Low-level ac
• Period average
• Vibrating wire (through interface modules)
• Smart sensors
o SDI-12
o RS-232
o Modbus
o DNP3
o TCP/IP
o RS-485
The CR1000X Datalogger
The CR1000X is used in a broad range of measurement and control functions. Rugged enough for
extreme conditions and reliable enough for remote environments, it plays a critical role in numerous
complex configurations. Used in applications all over the world, it is a powerful core component for your
data acquisition system.
2
Data Acquisition System Components
COMPONENTS
The CR1000X datalogger is the main part of a data acquisition system (see "Data Acquisition System
Components" on page 1 for more information). It has a central-processing unit (CPU), analog and digital
measurement inputs, analog and digital outputs, and memory. An operating system (firmware)
coordinates the functions of these parts in conjunction with the onboard clock and the CRBasic
application program.
The CR1000X can simultaneously provide measurement and communication functions. Low power
consumption allows the datalogger to operate for extended time on a battery recharged with a solar
panel, eliminating the need for ac power. The CR1000X suspends execution when primary power drops
below 9.6 V, reducing the possibility of inaccurate measurements.
The electronics are RF shielded and glitch protected by the sealed, stainless-steel canister, making the
CR1000X economical, small, and very rugged. A battery-backed clock assures accurate timekeeping.
OPERATIONS
The CR1000X measures almost any sensor with an electrical response, drives direct communications
and telecommunications, reduces data to statistical values, performs calculations, and controls external
devices. After measurements are made, data are stored in onboard, nonvolatile memory awaiting
transfer to the computer. Because most applications do not require that every measurement be
recorded, the program usually combines several measurements into computational or statistical
summaries, such as averages and standard deviations.
Programs are run by the CR1000X in either sequential mode or pipeline mode. In sequential mode,
each instruction is executed sequentially in the order it appears in the program. In pipeline mode, the
CR1000X determines the order of instruction execution to maximize efficiency.
PROGRAMS
A program directs the datalogger on how and when sensors are to be measured, calculations made,
and data stored. The application program for the CR1000X is written in CRBasic, which is a
programming language that includes measurement, data processing, and analysis routines, as well as
the standard BASIC instruction set. For simpler applications, Short Cut, a user-friendly program
generator, can be used to write the program. For more demanding programs, use CRBasic Editor. If
you are programming with CRBasic, you can utilize the extensive help available with the CRBasic
Editor software. Formal training is also available from Campbell Scientific.
Data Acquisition System Components
3
Wiring Panel and Terminal Functions
The CR1000X wiring panel provides ports and removable terminals for connecting sensors, power, and
communication devices. It is protected against surge, over-voltage, over-current, and reverse power.
The wiring panel is the interface to most datalogger functions so studying it is a good way to get
acquainted with the datalogger. Functions of the terminals are broken down into the following
categories:
• Analog input
• Pulse counting
• Analog output
• Communications
• Digital I/O
• Power input
• Power output
• Ground terminals
Analog Input
SE
DIFF
Single-Ended Voltage
Differential Voltage
Ratiometric/Bridge
Thermocouple
Current Loop
Period Average
4
1 2
⌐1¬
H L
✔
H
✔
✔
✔
✔
L
✔
✔
✔
3 4
⌐2¬
H L
✔
H
✔
✔
✔
Wiring Panel and Terminal Functions
✔
L
✔
✔
✔
5 6
⌐3¬
H L
✔
H
✔
✔
✔
✔
L
✔
✔
✔
7 8
⌐4¬
H L
✔
H
✔
✔
✔
✔
L
✔
✔
✔
9 10 11 12 13 14 15 16 VX1- RG1 RG2
VX4
⌐5¬
⌐6¬
⌐7¬
⌐8¬
H L H L H L H L
✔
H
✔
✔
✔
✔
L
✔
✔
✔
✔
H
✔
✔
✔
✔
L
✔
✔
✔
✔
H
✔
✔
✔
✔
L
✔
✔
✔
✔
H
✔
✔
✔
✔
L
✔
✔
✔
✔
✔
✔
Pulse Counting P1 P2 C1-C8
Switch-Closure
High Frequency
Low-level Ac
✔
✔
✔
✔
✔
✔
✔
✔
Analog Output
VX1-VX4
Switched Voltage Excitation
Voltage Output
C1-C81
5 Vdc
3.3 Vdc
12 Vdc
1C
✔
✔
✔
VX1-VX4 5V 12V SW12-1 SW12-2
✔
✔
✔
✔
✔
✔
terminals have limited drive capacity. Voltage levels are configured in pairs.
Communications
SDI-12
GPS
TTL 0-5 V
LVTTL 0-3.3 V
RS-232
RS-485 (Half Duplex)
RS-485 (Full Duplex)
I2C
SPI
SDM1
CPI/CDM
1SDM
C1
✔
PPS
Tx
Tx
C2
C3
✔
Tx
Tx
Tx
C4
C5
C6
C7
C8 RS-232/CPI
✔
✔
Tx
Rx
Tx
Rx
Tx
Rx
Tx
Rx
Tx
Rx
Tx
Rx
Tx
Rx
Tx
Rx
AB+
AB+
TxTx+
Rx- Rx+
SDA SCL SDA SCL SDA SCL SDA SCL
MOSI SCLK MISO
MOSI SCLK MISO
Data
Clk Enabl
Data
Clk Enabl
Rx
Rx
Rx
Rx
Rx
Rx
✔
✔
can be on either C1-C3 or C5-C7, but not both at the same time.
Communication Functions also include Ethernet and USB.
Digital I/O
General I/O
Pulse-Width Modulation Output
Timer Input
Interrupt
C1-C8
✔
✔
✔
✔
Power Input
The datalogger requires a power supply. It can receive power from a variety of sources, operate for
several months on non-rechargeable batteries, and supply voltage and control for many sensors and
devices. The datalogger operates with external power connected to the green POWER IN port on the
face of the wiring panel (see "Wiring Panel and Terminal Functions" on page 4). The positive power
lead connects to 12V. The negative lead connects to G. The power terminals are internally protected
against polarity reversal and high voltage transients. If the voltage on the POWER IN terminals exceeds
19 V, power is shut off to certain parts of the datalogger to prevent damaging connected sensors or
peripherals.
Wiring Panel and Terminal Functions
5
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 port. A UPS is often the
best power source for long-term installations. If external alkaline power is used, the alkaline battery
pack is connected directly to the POWER IN port. An external UPS consists of a primary-power source,
a charging regulator external to the datalogger, and an external battery.
Warning: Sustained input voltages in excess of those listed in the "Power Requirements" on
page 85, can damage the transient voltage suppression.
Be sure that power supply components match the specifications of the device to which they are
connected. When connecting power, first switch off the power supply, then insert the connector. Once
you make the connection, turn the power supply on. See "Troubleshooting Power Supplies" on page 71
for more information.
The CR1000X can receive power via the POWER IN port as well as 5 Vdc via a USB connection. If both
POWER IN and USB are connected, power will be supplied by whichever has the highest voltage. If
USB is the only power source, then the CS I/O port and the 12V, SW12, and 5V terminals will not be
operational. When powered by USB (no other power supplies connected) Status field Battery = 0.
Functions that will be active with a 5 Vdc source (USB) include sending programs, adjusting datalogger
settings, and making some measurements.
Note: The Status field Battery value and the destination variable from the Battery()
instruction (often called batt_volt in the Public table) reference the external battery
voltage. For detailed information about working with the internal battery, see "Internal
Battery" on page 59.
POWERING A DATALOGGER WITH A VEHICLE
If a datalogger 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 datalogger to stop measurements until the voltage again
equals or exceeds the lower limit. A second supply or charge regulator can be provided to prevent
measurement lapses during vehicle starting.
In vehicle applications, the earth ground lug should be firmly attached to the vehicle chassis with 12
AWG wire or larger.
POWER LED INDICATOR
When the datalogger is powered, the Power LED will turn on according to power and program states:
• Off: No power, no program running.
• 1 flash every 10 seconds: Powered, program running.
• 3 flashes every 10 seconds: Powered via USB, program running.
• Always on: Powered, no program running.
Power Output
The datalogger can be used as a power source for sensors and peripherals. Take precautions to
prevent damage to sensors or peripherals from over- or under-voltage conditions, and to minimize
6
Wiring Panel and Terminal Functions
errors. Exceeding current limits causes voltage output to become unstable. Voltage should stabilize
once current is again reduced to within stated limits. The following are available:
• 12V: unregulated nominal 12 Vdc. This supply closely tracks the primary datalogger 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 undervoltage conditions, and to minimize the error associated with the measurement of underpowered
sensors.
• 5V: regulated 5 Vdc. The 5 Vdc supply is regulated to within a few millivolts of 5 Vdc so long as
the main power supply for the datalogger does not drop below the minimum supply voltage. 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.
• SW12: program-controlled, switched 12 Vdc terminals. Often used to power devices such as
sensors that require 12 Vdc during measurement. Voltage on a SW12 terminal will change with
datalogger supply voltage. CRBasic instruction SW12() controls the SW12 terminal.
• CS I/O port: used to communicate with and often supply power to Campbell Scientific peripheral
devices
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. This means that 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.
• VX terminals: supply precise output voltage used by analog sensors to generate high resolution
and accurate signals. In this case, these terminals are regularly used with resistive-bridge
measurements (see "Resistance Measurements" on page 35 for more information). Using the
SWVX() instruction, VX terminals can also be used to supply a selectable, switched, regulated
3.3 or 5 Vdc power source to power digital sensors and toggle control lines.
• C terminals: can be set low or high as output terminals. With limited drive capacity, digital output
terminals are normally used to operate external relay-driver circuits. See also "Digital
Input/Output Specifications" on page 91.
See also "Power Output Specifications" on page 87.
Grounds
Proper grounding lends stability and protection to a data acquisition system. Grounding the datalogger
with its peripheral devices and sensors is critical in all applications. Proper grounding will ensure
maximum ESD protection and measurement accuracy. 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 datalogger grounds:
• Signal Ground ( ) - reference for single-ended analog inputs, excitation returns, and as a ground
for sensor shield wires.
• Power Ground (G) - return for 3.3 V, 5 V, 12 V, and digital sensors. 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.
Wiring Panel and Terminal Functions
7
• Resistive Ground (RG) - terminal for decoupling ground on RS-485 signals. Includes 100 Ω
resistance to ground. Also used for measuring Current (see "Current-Loop Measurements" on
page 33 for more information).
• Earth Ground Lug ( ) - connection point for heavy-gauge earth-ground wire. A good earth
connection is necessary to secure the ground potential of the datalogger and shunt transients
away from electronics. 14 AWG wire, minimum, is recommended.
Note: Several ground wires can be connected to the same ground terminal.
A good earth (chassis) ground will minimize damage to the datalogger and sensors by providing a lowresistance 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 5-foot copper-sheathed grounding rod
driven into the earth and connected to the large brass ground lug on the wiring panel with a 14 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 lightning-protection consultant.
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.
See also:
• "Minimizing Ground Loop Errors" on page 71
• "Minimizing Ground Potential Differences" on page 74
Communication Ports
The datalogger is equipped with ports that allow communication with other devices and networks, such
as:
• Computers
• Smart sensors
• Modbus and DNP3 networks
• Ethernet
• Modems
• Campbell Scientific PakBus® networks
• Other Campbell Scientific dataloggers
Campbell Scientific datalogger communication ports include:
• CS I/O
• RS-232/CPI
• USB
• Ethernet
• C terminals
8
Wiring Panel and Terminal Functions
USB PORT
One micro-B USB port, labeled USB, for communicating with a computer through datalogger support
software or through virtual Ethernet (RNDIS), and providing 5 Vdc power to the datalogger (powering
through the USB port has limitations - details are available in the specifications). The datalogger USB
port does not support USB flash or thumb drives. The USB connection supplies 5 V power as well as a
communication link, which is adequate for s and making some measurements. but a 12V battery will be
needed for field deployment.
ETHERNET PORT
RJ45 10/100 Ethernet port used for IP communications.
C TERMINALS FOR COMMUNICATIONS
C terminals are configurable for the following communication types:
• SDI-12
• RS-232
• RS-485
• TTL (0 to 5 V)
• LVTTL (0 to 3.3 V)
• SDM
Some communication types require more than one terminal, and some are only available on specific
terminals. This is shown in the datalogger specifications.
SDI-12 Port
SDI-12 is a 1200 baud protocol that supports many smart sensors. C1, C3, C5, and C7 can be
configured as SDI-12 ports. Maximum cable lengths depend on the number of sensors connected, the
type of cable used, and the environment of the application. Refer to the sensor manual for guidance.
For more information, see "SDI-12 Communications" on page 50.
RS-232, RS-485, TTL, and LVTTL Ports
RS-232, RS-485, TTL, and LVTTL communications are typically used for the following:
• Reading sensors with serial output
• Creating a multi-drop network
• Communication with other dataloggers or devices over long cables
Configure C terminals as serial ports using Device Configuration Utility or by using the SerialOpen()
CRBasic instruction. C terminals are configured in pairs for RS-232 or half-duplex RS-485. For fullduplex RS-485, all terminals are required. See also "Communication Protocols" on page 47.
SDM Port
SDM is a protocol proprietary to Campbell Scientific that supports several Campbell Scientific digital
sensor and communication input and output expansion peripherals and select smart sensors. It uses a
common bus and addresses each node. CRBasic SDM device and sensor instructions configure
Wiring Panel and Terminal Functions
9
terminals C1, C2, and C3 together to create an SDM port. Alternatively, terminals C5, C6, and C7 can
be configured together to be used as the SDM port by using the SDMBeginPort() instruction.
See also "Communications Specifications" on page 92.
CS I/O PORT
CS I/O is a Campbell Scientific proprietary input/output port as well as the proprietary serial
communication protocol that occurs over this port.
One nine-pin port, labeled CS I/O, is available for communicating with a computer or modem through
Campbell Scientific communication interfaces, modems, or peripherals. It is recommended that you
keep CS I/O cables short (maximum of a few feet). See also "Communications Specifications" on
page 92.
RS-232/CPI PORT
The datalogger includes one RJ45 module jack labeled RS-232-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. CPI ports also enable networking between compatible Campbell Scientific dataloggers.
Consult the manuals for CDM modules for more information.
CPI has the following power levels:
• Off: Not used.
• High power: Fully active.
• Low-power standby: Whenever possible.
• Low-power bus: Sets bus and modules to low power.
When used with an RJ45-to-DB9 converter cable, the RS-232/CPI port can be used as an RS-232 port.
It defaults to 115200 bps (in autobaud mode), 8 data bits, no parity, and 1 stop bit. Use Device
Configuration Utility or the SerialOpen() CRBasic instruction to change these options.
Programmable Logic Control
The datalogger can control instruments and devices such as:
• Controlling wireless cellular modem or GPS receiver to conserve power.
• Triggering a water sampler to collect a sample.
• Triggering a camera to take a picture.
• Activating an audio or visual alarm.
• Moving a head gate to regulate water flows in a canal system.
• Controlling pH dosing and aeration for water quality purposes.
• Controlling a gas analyzer to stop operation when temperature is too low.
• Controlling irrigation scheduling.
10
Wiring Panel and Terminal Functions
Control decisions can be based on time, an event, or a measured condition. Controlled devices can be
physically connected to C, VX, or SW12 terminals. Short Cut has provisions for simple on/off control.
Control modules and relay drivers are available to expand and augment datalogger control capacity.
• C terminals are selectable as binary inputs, control outputs, or communication ports. These
terminals can be set low (0 Vdc) or high (3.3 or 5 Vdc) using the PortSet() or WriteIO()
instructions. Other functions include device-driven interrupts, asynchronous communications and
SDI-12 communications. The high voltage for these terminals defaults to 5 V, but it can be
changed to 3.3 V using the PortPairConfig() instruction. Terminals C4, C5, and C7 can also
be configured for pulse width modulation with a maximum period of 36.4 s. A C terminal
configured for digital I/O is normally used to operate an external relay-driver circuit because the
terminal itself has limited drive capacity.
• VX terminals can be set low or high using the PortSet() or SWVX() instruction. For more
information on these instructions, see the CRBasic help.
• SW12 terminals can be set low (0 V) or high (12 V) using the SW12() instruction.
The following image 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).
EXAMPLE: TURN MODEM ON FOR 10 MINUTES HOURLY
In the case of a cell modem, control is based on time. The modem requires 12 Vdc power, so connect
its power wire to a datalogger SW12 terminal. The following code snip turns the modem on for the first
ten minutes of every hour using the TimeIsBetween() instruction embedded in an If/Then logic
statement:
If TimeIsBetween(0,10,60,Min) Then
SW12(SW12_1,1,1) 'Turn phone on.
Else
SW12(SW12_1,0,1) 'Turn phone off.
EndIf
Wiring Panel and Terminal Functions
11
Setting Up the Datalogger
The basic steps to setting up your datalogger to measure data include:
1. Configuring your connection.
2. Testing communication (optional).
3. Connecting the datalogger to the computer.
4. Creating a program.
5. Sending that program to the datalogger.
Setting up Communications with the Datalogger
The first step in setting up and communicating with your datalogger is to configure your connection.
Communication peripherals, dataloggers, and software must all be configured for communication. In
addition to this instruction and manuals for your specific peripherals, refer to your datalogger support
software manual and help for guidance.
The default settings for the datalogger allow it to communicate with a computer via USB, RS-232, or
Ethernet, and to accept and execute user application programs. For other communication methods or
more complex applications, some settings may need adjustment. Settings can be changed through
Device Configuration Utility or through datalogger support software.
You can configure your connection using any of the following options. The simplest is via USB. For
detailed instruction, see:
• "USB or RS-232 Communications" on page 12
• "Virtual Ethernet over USB (RNDIS)" on page 13
• "Ethernet Communications" on page 14
For other configurations, see the LoggerNet EZSetup Wizard help. Context-specific help is given in
each step of the wizard by clicking the Help button in the bottom right corner of the window. For
complex datalogger networks, use Network Planner.
USB OR RS-232 COMMUNICATIONS
Setting up a USB or RS-232 connection is a good way to begin communicating with your datalogger.
Because these connections do not require configuration (like an IP address), you need only set up the
communication between your computer and the datalogger. Watch a video or use the following
instructions.
Initial setup instruction follows. These settings can be revisited using the datalogger support software
Edit Datalogger Setup option (
).
1. Using datalogger support software, launch the EZSetup Wizard.
• PC200W and PC400 users, click the Add Datalogger button (
).
• LoggerNet users, click the Setup ( ) option, click the View menu to ensure you are in the
EZ (Simplified) view, then click the Add Datalogger button.
2. Click Next.
12
Setting Up the Datalogger
3. Select your datalogger from the list, type a name for your datalogger (for example, a site or
project name), and click Next.
4. If prompted, select the Direct Connect connection type and click Next.
5. If this is the first time connecting this computer to a CR1000X via USB, click the Install
USB Driver button, select your datalogger, click Install, and follow the prompts to install the
USB drivers.
6. Plug the datalogger into your computer using a USB or RS-232 cable. The USB connection
supplies 5 V power as well as a communication link, which is adequate for setup, but a 12V
battery will be needed for field deployment. If using RS-232, external power must be provided to
the datalogger and a CPI/RS-232 RJ45 to DB9 cable is required to connect to the computer.
Note: The Power LED on the datalogger indicates the program and power state. Because the
datalogger ships with a program set to run on power-up, the Power LED flashes 3 times
every 10 seconds when powered over USB. When powered with a 12 V battery, it flashes 1
time every 10 seconds.
7. From the COM Port list, select the COM port used for your datalogger.
8. USB and RS-232 connections do not typically require a COM Port Communication Delay - this
allows time for the hardware devices to "wake up" and negotiate a communication link. Accept
the default value of 00 seconds and click Next.
9. The baud rate and PakBus® address must match the hardware settings for your datalogger. A
USB connection does not require a baud rate selection, RS-232 connections default to 115200
baud, and the default PakBus address is 1.
• Set an Extra Response Time if you have a difficult or marginal connection and you want the
datalogger support software to wait a certain amount of time before returning a
communication failure error.
• LoggerNet and PC400 users can set a Max Time On-Line to limit the amount of time the
datalogger remains connected. When the datalogger is contacted, communication with it is
terminated when this time limit is exceeded. A value of 0 in this field indicates that there is
no time limit for maintaining a connection to the datalogger.
10. Click Next.
11. By default, the datalogger does not use a security code or a PakBus encryption key. Therefore,
the Security Code can be set to 0 and the PakBus Encryption Key can be left blank. If either
setting has been changed, enter the new code or key. See "Datalogger Security" on page 56 for
more information.
12. Click Next.
13. Review the Communication Setup Summary. If you need to make changes, click the Previous
button to return to a previous window and change the settings.
Setup is now complete, and the EZSetup Wizard allows to you click Finish or click Next to test your
communication, set the datalogger clock, and send a program to the datalogger.
VIRTUAL ETHERNET OVER USB (RNDIS)
The datalogger supports RNDIS (virtual Ethernet over USB). This allows the datalogger to
communicate via TCP/IP over USB. Watch a video or use the following instructions.
Setting Up the Datalogger
13
Connecting to Your Datalogger via RNDIS
1. Supply power to the datalogger. If connecting via USB for the first time, you must first install USB
drivers by using Device Configuration Utility (select your datalogger, then on the main page, click
Install USB Driver). Alternately, you can install the USB drivers using EZ Setup. A USB
connection supplies 5 V power (as well as a communication link), which is adequate for setup, but
a 12 V battery will be needed for field deployment.
Note: Ensure the datalogger is connected directly to the computer USB port (not to a
USB hub).
2. Physically connect your datalogger to your computer using a USB cable, then open Device
Configuration Utility and select your datalogger.
3. Retrieve your IP Address. On the bottom, left side of the screen, select Use IP Connection, then
click the browse button next to the Communication Port box. Note the IP Address (default is
192.168.66.1). If you have multiple dataloggers in your network, more than one datalogger may
be returned. Ensure you select the correct datalogger by verifying the datalogger serial number or
station name (if assigned).
4. A datalogger’s Virtual IP address can be used to connect to it using Device Configuration Utility or
other computer software, or to view the datalogger’s internal web page in a browser. To view the
web page, open a browser and type the IP address you retrieved in the previous step (e.g.,
192.168.66.1) into the address bar.
To secure your datalogger from access by others who have access to your network, we recommend
that you set security settings and establish access permissions using .csipasswd. For more
information, see "Creating a .csipasswd File" on page 57.
ETHERNET COMMUNICATIONS
The CR1000X offers a 10/100 Ethernet connection you can configure using Device Configuration Utility.
You will use this utility to enter the datalogger IP Address, Subnet Mask, and IP Gateway address. After
this, you can use the EZSetup Wizard to set up communications with the datalogger. If you already
have the datalogger IP information, you can skip these steps and go directly to "Setting up Ethernet
Communications between the Datalogger and the Computer" on page 15.
Configuring Datalogger Ethernet Settings
1. Supply power to the datalogger. If connecting via USB for the first time, you must first install USB
drivers by using Device Configuration Utility (select your datalogger, then on the main page, click
Install USB Driver). Alternately, you can install the USB drivers using EZ Setup. A USB
connection supplies 5 V power (as well as a communication link), which is adequate for setup, but
a 12 V battery will be needed for field deployment.
2. Connect an Ethernet cable to the 10/100 Ethernet port on the datalogger. The yellow and green
Ethernet port LEDs display activity approximately one minute after connecting. If you do not see
activity, contact your network administrator. For more information, see "Ethernet LEDs" on
page 15.
3. Using datalogger support software (LoggerNet, PC400, or PC200W), enter the Device
Configuration Utility ( ).
4. Select the CR1000X Series datalogger from the list
5. Select the port assigned to the datalogger from the Communication Port list. If connecting via
Ethernet, check the Use IP Connection button.
14
Setting Up the Datalogger
6. By default, this datalogger does not use a PakBus encryption key, so the PakBus Encryption Key
box can be left blank. If this setting has been changed, enter the new code or key. See
"Datalogger Security" on page 56 for more information.
7. Click Connect.
8. On the Deployment tab, click the Ethernet subtab.
9. The Ethernet Power setting allows you to reduce the power consumption of the datalogger. If
there is no Ethernet connection, the datalogger will turn off its Ethernet interface for the time
specified before turning it back on to check for a connection. Select an option from the list.
10. Enter the IP Address, Subnet Mask, and IP Gateway. These values should be provided by your
network administrator. A static IP address is recommended. If you are using DHCP, note the IP
address assigned to the datalogger on the right side of the window. When the IP Address is set to
0.0.0.0, the default, the information displayed on the right side of the window updates with the
information obtained from the DHCP server. Note, however, that this address is not static and
may change. An IP address here of 169.254.###.### means the datalogger was not able to
obtain an address from the DHCP server. Contact your network administrator for help.
11. Click Apply to save your changes.
Ethernet LEDs
When the datalogger is powered, the 10/100 Ethernet port will turn on with Ethernet activity:
• Solid Yellow: Valid Ethernet link.
• No Yellow: Invalid Ethernet link.
• Flashing Yellow: Ethernet activity.
• Solid Green: 100 Mbps link.
• No Green: 10 Mbps link.
Setting up Ethernet Communications between the Datalogger and the
Computer
Once you have configured the Ethernet settings or obtained the IP information for your datalogger, you
can set up communication between your computer and the datalogger over Ethernet.
Initial setup instruction follows. These settings can be revisited using the datalogger support software
Edit Datalogger Setup option (
).
1. Using datalogger support software, launch the EZSetup Wizard.
• PC400 users, click the Add Datalogger button (
).
• LoggerNet users, click the Setup ( ) option, click the View menu to ensure you are in the
EZ (Simplified) view, then click the Add Datalogger button.
Note: PC200W does not allow IP connections.
2. Click Next.
3. Select the CR1000X Series from the list, type a name for your datalogger (for example, a site or
project name), and click Next.
4. Select the IP Port connection type and click Next.
Setting Up the Datalogger
15
5. Type the datalogger IP address followed by a colon, then the port number of the datalogger in the
Internet IP Address field (these were set up when "Ethernet Communications" on page 14). They
can be accessed in Device Configuration Utility on the Ethernet subtab. Leading 0s must be
omitted. For example:
• IPv4 addresses are entered as 192.168.1.2:6785
• IPv6 addresses must be enclosed in square brackets. They are entered as
[2001:db8::1234:5678]:6785
6. The PakBus® address must match the hardware settings for your datalogger. The default
PakBus address is 1.
• Set an Extra Response Time if you want the datalogger support software to wait a certain
amount of time before returning a communication failure error.
• LoggerNet and PC400 users can set a Max Time On-Line to limit the amount of time the
datalogger remains connected. When the datalogger is contacted, communication with it is
terminated when this time limit is exceeded. A value of 0 in this field indicates that there is
no time limit for maintaining a connection to the datalogger.
7. Click Next.
8. By default, the datalogger does not use a security code or a PakBus encryption key. Therefore
the Security Code can be set to 0 and the PakBus Encryption Key can be left blank. If either
setting has been changed, enter the new code or key. See "Datalogger Security" on page 56 for
more information.
9. Click Next.
10. Review the Communication Setup Summary. If you need to make changes, click the Previous
button to return to a previous window and change the settings.
Setup is now complete, and the EZSetup Wizard allows you click Finish or click Next to test your
communication, set the datalogger clock, and send a program to the datalogger. See "Testing
Communication and Completing EZ Setup" on page 16 for more information.
Testing Communication and Completing EZ Setup
1. Using datalogger support software EZ Setup, access the Communication Test window. This
window is accessed during EZ Setup (see "USB or RS-232 Communications" on page 12 for
more information). Alternatively, you can double-click a datalogger from the station list to open
the EZ Setup Wizard and access the Communication Test step from the left side of the window.
2. Ensure the datalogger is connected to the computer, select Yes to test the communication, then
click Next to initiate the test. To troubleshoot an unsuccessful test, see "Tips and
Troubleshooting" on page 65.
3. With a successful connection, the Datalogger Clock window displays the time for both the
datalogger and the computer.
• The Adjusted Server Date/Time displays the current reading of the clock for the computer
or server running your datalogger support software. If the Datalogger Date/Time and
Adjusted Server Date/Time don't match, you can set the datalogger clock to the Adjusted
Server Date/Time by clicking Set Datalogger Clock.
• Use the Time Zone Offset to specify a positive or negative offset to apply to the computer
time when setting the datalogger clock. This offset will allow you to set the clock for a
16
Setting Up the Datalogger
datalogger that needs to be set to a different time zone than the time zone of the computer
(or to accommodate for changes in daylight saving time).
4. Click Next.
5. The datalogger ships with a default GettingStarted program. If the datalogger does not have a
program, you can choose to send one by clicking the Select and Send Program button. Click
Next.
6. LoggerNet only - Watch a video or use the following instructions:
• The Datalogger Table Output Files window displays the data tables available to be
collected from the datalogger and the output file name. To include a data table in scheduled
collection, select the data table from the Tables list and check the Table Collected During
Data Collection box. Select a Data File Option: Append to End of File adds new data to the
end of the existing data file, Overwrite Existing File replaces the existing file with a newly
created file, and No Output File results in no data file being written to disk. Make note of the
Output File Name and location. Click Next.
• Check Scheduled Collection Enabled to have LoggerNet collect data from the datalogger
according to a schedule. Set the Base Date and Time to begin scheduled collections. Set a
Collection Interval, then click Next.
7. Click Finish.
Connecting the Datalogger to a Computer
Once you have configured your connection (see "Setting up Communications with the Datalogger" on
page 12 for more information), you can connect the datalogger to your computer.
• PC200W and PC400 users, select the datalogger from the list and click the Connect button (
• LoggerNet users, select Main and click the Connect button (
) on the LoggerNet toolbar, select
the datalogger from the Stations list, then click the Connect button (
To disconnect, click the Disconnect button (
).
).
).
See also "Communication Protocols" on page 47.
Creating a Program in Short Cut
Use the Short Cut software to generate a program for your datalogger. Short Cut is included with your
datalogger support software.
Watch a video or use the following instructions.
1. Using datalogger support software, launch Short Cut.
• PC200W and PC400 users, click the Short Cut button (
).
• LoggerNet users, click Program then click the Short Cut button (
).
2. Click Create New Program.
Setting Up the Datalogger
17
3. Select the CR1000X Series datalogger and click Next.
Note: The first time Short Cut is run, a prompt will appear asking for a choice of noise
rejection. Select 60 Hz Noise Rejection for North America and areas using 60 Hz ac voltage.
Select 50 Hz Noise Rejection for most of the Eastern Hemisphere 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.
To change the noise rejection or sensor support option for future programs, use the Program
menu.
4. A list of Available Sensors and Devices and Selected Measurements Available for Output display.
Battery voltage BattV and internal temperature PTemp_C are selected by default. During
operation, battery and temperature should be recorded at least daily to assist in monitoring
system status.
5. Use the Search feature or expand folders to locate your sensor or device. Double-click on a
sensor or measurement in the Available Sensors and Devices list to configure the device (if
needed) and add it to the Selected list.
6. If the sensor or device requires configuration, a window displays with configuration options. Click
Help at the bottom of the window to learn more about any field or option.
7. Click OK.
8. Click Wiring Diagram on the left side of the window to see how to wire the sensor to the
datalogger. With the power disconnected from the datalogger, insert the wires as directed in the
diagram. Ensure you clamp the terminal on the conductor, not the wire insulation. Use the
included flat-blade screwdriver to open/close the terminals.
9. Click Sensors on the left side of the window to return to the sensor selection window.
10. Use the Output Setup options to specify how often measurements are to be made and how often
outputs are to be stored. Note that multiple output intervals can be specified, one for each output
table (Table1 and Table2 tabs).
11. In the Table Name box, type a name for the table.
12. Select a Data Output Storage Interval.
13. Optionally, select to copy the table to an external storage device.
14. Check the Advanced Outputs option if you want to specify the number of records and data events
to store, set output intervals, specify measurements to evaluate, or set flags based on the value
of a variable.
15. Click Next.
18
Setting Up the Datalogger
16. Select the measurement from the Selected Measurements Available for Output list, then click an
output processing option to add the measurement to the Selected Measurements for Output list.
17. Click Finish to compile the program. Replace the untitled.cr1x default name and click Save.
18. If LoggerNet or other datalogger support software is running on your computer, and the
datalogger is connected to the computer (see "Connecting the Datalogger to a Computer" on
page 17 for more information), you can choose to send the program.
Note: A good practice is to always retrieve data from the datalogger before sending a
program; otherwise, data may be lost. See "Collecting Data" on page 22 for detailed
instruction.
If your data acquisition requirements are simple, you can probably create and maintain a datalogger
program exclusively with Short Cut. If your data acquisition needs are more complex, the files that Short
Cut creates are a great source for programming code to start a new program or add to an existing
custom program using CRBasic. See the CRBasic Editor help for detailed information on program
structure, syntax, and each instruction available to the datalogger.
Note: Once a Short Cut generated program has been edited with CRBasic Editor, it can no
longer be modified with Short Cut.
Sending a Program to the Datalogger
The datalogger requires a CRBasic program to direct measurement, processing, control, and data
storage operations. The program file may use the extension .CR1x or .dld.
A good practice is to always retrieve data from the datalogger before sending a program; otherwise,
data may be lost. To collect data using LoggerNet, connect to your datalogger and click the Collect Now
button ( ). Some methods of sending a program give the option to retain data when possible.
Regardless of the program upload tool used, data will be erased when a new program is sent if any
change occurs to one or more data table structure in the following list:
• Data table name(s)
• Number of bytes per field
• Data output interval or offset
• Field type, size, name, or position
• Number of fields per record
• Number of records in table
Setting Up the Datalogger
19
SENDING A PROGRAM USING DATALOGGER SUPPORT SOFTWARE
Watch a video or use the following instructions.
1. Connect the datalogger to your computer (see "Connecting the Datalogger to a Computer" on
page 17 for more information).
2. Using your datalogger support software, click Send New or Send Program (located in the Current
Program section on the right side of the window).
3. Navigate to the location of the program, select it, and click Open.
4. Confirm that you would like to proceed and erase all data tables saved on the datalogger. The
program will send, compile, then display results.
After sending a program, it is a good idea to monitor the data to make sure it is measuring as you
expect. See "Working with Data" on page 21 for more information.
Program Run Options
When sending a program via File Control, Short Cut, or CRBasic, you can choose to have programs
Run on Power-up and Run Now. Run Now will run the program when it is sent to the datalogger. Run
on Power-up runs the program when the datalogger is powered up. Selecting both Run Now and Run
on Power-up will invoke both options.
20
Setting Up the Datalogger
Working with Data
By default, the datalogger includes three tables: Public, Status, and DataTableInfo. Each of these tables
only contains the most recent measurements and information.
• The Public table contains the measurements as they are made. It is updated at the scan interval
set within the datalogger program.
• The Status table includes information on the health of the datalogger and is updated only when
viewed.
• The DataTableInfo table reports statistics related to data tables. It also only updates when
viewed.
• User-defined data tables update at the schedule set within the program.
Monitoring Data
Follow a tutorial or use the following instructions:
PC200W and PC400 users, click the Connect button ( ), then click the Monitor Data tab. When this
tab is first opened for a datalogger, values from the Public table are displayed. To view data from other
tables, click the Add button ( ), select a table or field from the list, then drag it into a cell on the Monitor
Data tab.
LoggerNet users, select Main and click the Connect button (
) on the LoggerNet toolbar, select the
datalogger from the Stations list, then click the Connect button (
table to view using the Table Monitor list.
). Once connected, you can select a
Working with Data
21
Collecting Data
The datalogger writes to data tables according to the schedule set within the CRBasic program (see
"Creating Data Tables in a Program" on page 25 for more information). After the program has been
running for enough time to generate data records, data may be collected and reviewed via your
datalogger support software. Collections may be done manually, or automatically through scheduled
collections set in LoggerNet Setup. Follow a tutorial or use the following instructions.
COLLECTING DATA USING LOGGERNET
1. LoggerNet users, select Main and click the Connect button (
) on the LoggerNet toolbar, select
the datalogger from the Stations list, then click the Connect button (
2. Click the Collect Now button (
).
).
3. After the data is collected, the Data Collection Results window displays the tables collected and
where they are stored on the computer.
4. Click View File to view the data.
COLLECTING DATA USING PC200W OR PC400W
1. PC200W and PC400 users, click the Connect button (
).
2. Click the Collect Data tab.
3. Select an option for What to Collect. Either option creates a new file if one does not already exist.
• New data from datalogger (Append to data files): Collects only the data in the selected
tables stored since the last data collection and appends this data to the end of the existing
table files on the computer.
• All data from datalogger (Overwrite data files): Collects all of the data in the selected tables
and replaces the existing table files on the computer.
4. Select the tables to collect from the list at the bottom of the window.
5. Click Start Data Collection.
6. The Data Collection Results window displays the tables collected and where they are stored on
the computer.
7. Click View File to view the data.
Viewing Historic Data
View historic data in a spreadsheet format using View Pro. View Pro also contains tools for visualizing
data in several graphical layouts. Follow a tutorial or use the following instructions:
Once the datalogger has had ample time to take multiple measurements, you can collect and review the
data.
1. To view the most recent data, connect the datalogger to your computer and collect your data (see
"Collecting Data" on page 22 for more information).
22
Working with Data
2. Open View Pro:
• LoggerNet users select Data and click View Pro (
) on the LoggerNet toolbar.
• PC200W and PC400 users click the View Data Files via View Pro toolbar button (
).
3. Click the Open toolbar button ( ), navigate to the directory where you saved your tables (the
default directory is C:\Campbellsci\[your datalogger software application]).
About Data Tables
A data table is essentially a file that resides in datalogger memory. The file consists of five or more
rows. Each row consists of columns, or fields. The first four rows constitute the file header. Subsequent
rows contain data records. Data tables may store individual measurements, individual calculated
values, or summary data such as averages, maxima, or minima.
The file is written to each time data are directed to that file. The datalogger records data based on time
or event. You can retrieve data based on a schedule or by manually choosing to collect data using
datalogger support software (see "Collecting Data" on page 22). The number of data tables is limited to
250.
Example of a typical data table
TOA5, MyStation, CR1000X, 142, CRxxx.Std.01, CPU:MyTemperature.CR1X, 1958, OneMin
TIMESTAMP
RECORD
BattV_Avg
PTemp_C_Avg
Temp_C_Avg
TS
RN
Volts
Deg C
Deg C
Avg
Avg
Avg
2016-03-08 14:24:00
0
13.68
21.84
20.71
2016-03-08 14:25:00
1
13.65
21.84
20.63
2016-03-08 14:26:00
2
13.66
21.84
20.63
2016-03-08 14:27:00
3
13.58
21.85
20.62
2016-03-08 14:28:00
4
13.64
21.85
20.52
2016-03-08 14:29:00
5
13.65
21.85
20.64
TABLE DEFINITIONS
Each data table is associated with overhead information, referred to as “table definitions,” that becomes
part of the file header (first few lines of the file) when data are downloaded to a computer. These include
the table format, datalogger type and OS, name of the CRBasic program running in the datalogger,
name of the data table (limited to 20 characters), and the alphanumeric field names to attach at the
head of data columns,
First Header Row
The first header row of the data table is the environment line, which consists of eight fields. The
following list describes the fields using the previous table entries as an example:
• 1: TOA5 - Table output format. Changed via LoggerNet Setup (
) Standard View, Data Files tab.
• 2: MyStation - Station name. Changed via LoggerNet Setup, Device Configuration Utility, or
CRBasic program.
• 3: CR1000X - Datalogger model.
• 4: 142 - Datalogger serial number.
• 5: CRxxx.Std.01 - Datalogger OS version. Changed via installation of a new OS.
Working with Data
23
• 6: CPU:MyTemperature.CR1X - Datalogger program name. Changed by sending a new program
(see "Sending a Program to the Datalogger" on page 19 for more information).
• 7: 1958 - Datalogger program signature. Changed by revising a program or sending a new
program (see "Sending a Program to the Datalogger" on page 19 for more information).
• 8: OneMin - Table name. Changed by revising a program (see "Creating Data Tables in a
Program" on page 25 for more information).
Second Header Row
The second header row reports field names. Default field names are a combination of the variable
names (or aliases) 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. A list of these abbreviations follows in "Data Process
Names and Abbreviations" on page 24.
If a field is an element of an array, the field name will be followed by a 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 four field names:
Values(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 each scalar value defined by the table.
If the default field names are not acceptable to the programmer, the FieldNames() instruction can be
used in the CRBasic program to customize the names. TIMESTAMP, RECORD, BattV_Avg,
PTemp_C_Avg, and Temp_C_Avg are the default field names in the previous "Example of a typical data
table" on page 23.
Third Header Row
The third header row identifies engineering units for that field of data. These units are declared at the
beginning of a CRBasic program, as shown in "Creating Data Tables in a Program" on page 25. In
Short Cut, units are chosen when sensors or measurements are added. Units are strictly for
documentation. The datalogger does not make use of declared units, nor does it check their accuracy.
Fourth Header Row
The fourth header row reports abbreviations of the data process used to produce the field of data.
Data Process Names and Abbreviations
• Totalize Tot
• Average Avg
• Maximum Max
• Minimum Min
• Sample at Max or Min SMM
• Standard Deviation Std
• Moment MMT
• Sample No abbreviation
• Histogram1 Hst
24
Working with Data
• Histogram4D H4D
• FFT FFT
• Covariance Cov
• Level Crossing LCr
• WindVector WVc
• Median Med
• ET ETsz
• Solar Radiation (from ET) RSo
• Time of Max TMx
• Time of Min TMn
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.
1Hst
Data Records
Subsequent rows are called data records. They include observed data and associated record keeping.
The first field is a timestamp (TS), and the second field is the record number (RN).
The timestamp shown represents the time at which the data is written. Therefore, because the scan rate
of the program MyTemperature.CR1X is 1 second, Temp_C_Avg in record number 3 in the previous
"Example of a typical data table" on page 23, shows the average of the measurements taken over the
minute beginning at 14:26:01 and ending at 14:27:00. As another example, consider rainfall measured
every second with a daily total rainfall recorded in a data table written at midnight. The record
timestamped 2016-03-08 00:00:00 will contain the total rainfall beginning at 2016-03-07 00:00:01 and
ending at 2016-03-08 00:00:00.
Creating Data Tables in a Program
Data are stored in tables as directed by the CRBasic program. In Short Cut, data tables are created in
the Output steps (see "Creating a Program in Short Cut" on page 17). Data tables are created within the
CRBasic datalogger program using the DataTable()/EndTable instructions. They are placed after
variable declarations and before the BeginProg 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. These instructions include:
DataTable()
'Output Trigger Condition(s)
'Output Processing Instructions
EndTable
For more information, see the CRBasic help.
Working with Data
25
Memory and Data Storage
The datalogger includes three types of memory: SRAM, Flash, and Serial Flash. A memory card slot is
also available for an optional microSD card. Note that the datalogger USB port does not support USB
flash or thumb drives (see "Communication Ports" on page 8 for more information). Memory storage is
For additional information on datalogger memory, visit the Campbell Scientific blog article, "How to
Know when Your Datalogger Memory is Getting Full."
Memory Allocation
Data table SRAM and the CPU drive are automatically partitioned for use in the datalogger. The USR
drive can be partitioned as needed. The CRD drive is automatically partitioned when a memory card is
installed. Primary storage for measurement data are those areas in SRAM allocated to data tables.
The CPU and USR drives use the FAT file system. 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 a relatively small amount of solid
state RAM and so is accessed very quickly.
SRAM
SRAM holds program variables, communication buffers, final storage data, and, if allocated, the USR
drive. An internal lithium battery retains this memory when primary power is removed.
The structure of the datalogger SRAM memory is as follows:
• "Static" Memory: This is memory used by the operating system, regardless of the running
program. This sector is rebuilt at power-up, program recompile, and watchdog events.
• Operating Settings and Properties: Also known as the "Keep" memory, this memory is used to
store settings such as PakBus address, station name, beacon intervals, neighbor lists, etc. This
memory also stores dynamic properties such as the routing table, communication timeouts, etc.
• CRBasic Program Operating Memory: Stores the currently compiled and running user program.
This sector is rebuilt on power-up, recompile, and watchdog events.
• Variables & Constants: This memory stores the public 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.
• Final-Storage Memory: This memory stores data. Auto-allocated tables fill whatever memory
remains after all other demands are satisfied. A compile error occurs if insufficient memory is
available for user-allocated data tables. This memory is given lowest priority in SRAM memory
allocation.
• Communication Memory 1: Memory used for construction and temporary storage of PakBus
packets.
26
Memory and Data Storage
• Communication Memory 2: Memory used to store 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. You can increase the Communication Allocation field in Device
Configuration Utility to increase this allocation.
• USR drive: Optionally allocated. Holds image files. Holds a copy of final-storage 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.
DATA STORAGE
Measurement data is primarily stored in data tables within SRAM. Data are usually erased from this
area when a program is sent to the datalogger.
During data table initialization, memory sectors are assigned to each data table according to the
parameters set in the program. Program options that affect the allocation of memory include the Size
parameter of the DataTable() instruction, the Interval and Units parameters of the
DataInterval() instruction, and the Interval and Units parameters of the Scan() instruction.
The datalogger uses those parameters to assign sectors in a way that maximizes the life of its memory.
By default, data storage memory sectors are organized as ring memory. When the ring is full, oldest
data are overwritten by newest data. Using the FillStop statement sets a program to stop writing to
the data table when it is full, and no more data are stored until the table is reset. To see the total
number of records that can be stored before the oldest data are overwritten, or to reset tables, go to
Station Status | Table Fill Times in your datalogger support software.
Data concerning the datalogger memory are posted in the Status and DataTableInfo tables.
USR DRIVE
Battery-backed SRAM can be partitioned to create a FAT USR drive, analogous to partitioning a second
drive on a computer hard disk. Certain types of files are stored to USR to reserve limited CPU drive
memory for datalogger programs and calibration files. Partitioning also helps prevent interference from
data table SRAM. 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, certain
configuration files, files written for FTP retrieval, HTML files for viewing with web access, and files
created with the TableFile() instruction. Measurement data can also be stored on USR as discrete
files by using the TableFile() instruction. Files on USR can be collected using the datalogger
support software Retrieve command in File Control, or automatically using the LoggerNet Setup | File
Retrieval tab functions.
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
set manually by accessing it in the Settings Editor, or programmatically by loading a CRBasic program
Memory and Data Storage
27
with a USR drive size entered in a SetSetting() instruction. Partition the 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 2990000 bytes.
Note: Placing an optional USR size setting in the CRBasic program overrides manual
changes to USR size. When USR size is changed manually, the CRBasic program restarts
and the programmed size for USR takes immediate effect.
Files in the USR drive can be managed through datalogger support software File Control or through the
FileManage() instruction in CRBasic program.
Flash Memory
The datalogger operating system is stored in a separate section of flash memory. To update the
operating system, see "Updating the Operating System" on page 62.
Serial Flash Memory
Serial flash memory holds the CPU drive, the web page, and datalogger settings. Because flash
memory has a limited number of erase/write cycles, care must be taken to avoid continuously writing to
files on the CPU drive.
CPU DRIVE
The serial flash memory CPU drive contains datalogger programs and other files.This memory is
managed in File Control.
Caution: When writing to files under program control, take care to write infrequently in order to
prevent premature failure of serial flash memory.
Also, see "System Specifications" on page 85 for information on datalogger memory.
MicroSD (CRD: Drive) Storage
The datalogger has a microSD card slot for removable, supplemental storage. The card can be
configured as an extension of the datalogger final storage memory or as a repository of discrete data
files. In data file mode, sub folders are not supported.
The CRD: drive uses microSD cards exclusively. Its primary purpose is the storage of data files in a
compact binary format. Campbell Scientific recommends and supports only the use of microSD cards
obtained from Campbell Scientific. These cards are industrial-grade and have passed Campbell
Scientific hardware testing. Use of consumer grade cards substantially increases the risk of data loss.
Following are listed advantages Campbell Scientific cards have over less expensive commercial-grade
cards:
• Less susceptible to failure and data loss.
• Match the datalogger operating temperature range.
• Provide faster read/write times.
• Include vibration and shock resistance.
• Have longer life spans (more read/write cycles).
A maximum of 30 data tables can be created on a microSD card. When a data table is sent to a
microSD card, a data table of the same name in SRAM is used as a buffer for transferring data to the
28
Memory and Data Storage
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 card, the datalogger 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 datalogger will warn that the card is not being used. However, the CRBasic program runs anyway
and data are stored to SRAM. When a card is inserted later, data accumulated in the SRAM table are
copied to the card.
A microSD card can also facilitate the use of powerup.ini (see "File Management via Powerup.ini" on
page 30 for more information).
FORMATTING MICROSD CARDS
The datalogger accepts microSD cards formatted as FAT16 or FAT32; however, FAT32 is
recommended. Otherwise, some functionality, such as the ability to manage large numbers of files
(>254) is lost. The datalogger formats memory cards as FAT32.
Because of the way the FAT32 card format works, you can avoid long datalogger compile times with a
freshly formatted card by first formatting the new card on a computer, then copying a small file to the
card from the computer, and then deleting the file with the computer. When the small file is copied to the
card, the computer updates a sector on the card that which allows the datalogger program to compile
faster. This only needs to be done once when the card is formatted. If you have the datalogger update
the card sector, the first datalogger program compile with the card can take as long as 10 minutes. After
that, compile times will be normal.
MICROSD CARD PRECAUTIONS
Observe the following precautions when using optional storage cards:
• Before removing a card from the datalogger, disable the card by pressing the Eject button and
wait for the green LED. You then have 15 seconds to pull the card before normal operations
resume.
• Do not remove a storage card while the drive is active, or data corruption and damage to the card
may result.
• Prevent data loss by collecting data before sending a program from the storage card to the
datalogger. Sending a program from the storage card to the datalogger often erases all data.
MICROSD LED INDICATOR
When the datalogger is powered and a microSD is connected, the microSD LED will turn on according
to power and program states:
• Red flash: Card read/write activity.
• Solid green: Formatted card inserted, powered up. This LED also indicates it is OK to remove
card. The Eject button must be pressed before removing a card to allow the datalogger to store
buffered data to the card and then power it off.
• Solid orange: Error.
• Dim/flashing orange: Card has been removed and has been out long enough that CPU memory
has wrapped and data is being overwritten without being stored to the card.
Memory and Data Storage
29
File Management via Powerup.ini
Another way to upload a program, install a datalogger OS, or format a drive is to create a powerup.ini
program. The program is created with a text editor and saved to a memory card or SC115, along with
associated files. Alternatively, the powerup.ini program and associated files can be saved to the
datalogger using the datalogger support software File Control | Send command. With the memory card
or SC115 connected, or with the powerup.ini file saved in the datalogger memory, a power cycle to the
datalogger begins the process chosen in the powerup.ini program.
When uploading a program, the following rules determine what datalogger program to run:
• If the Run Now program is changed, then it is the program that runs.
• If no change is made to the Run Now program, but the 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.
Syntax for the powerup.ini program and available options follow.
SYNTAX
Syntax for powerup.ini is:
Command,File,Device
where,
• Command is one of the numeric commands in the following table.
• File is the accompanying operating system or user program file. File name can be up to 22
characters long.
• Device is the datalogger 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.
Command
Action
Details
11
2
5
61
7
9
13
14
15
Run always, Copies a program file to a drive and sets the program to both Run Now and Run on
preserve data Power Up. Data on a memory card from the previously running program will be
preserved if table structures have not changed.
Run on
Copies a program file to a drive and sets the program to Run Always unless command 6
power up
or 14 is used to set a separate Run Now program.
Format
Formats a drive.
Run now,
Copies a program file to a drive and sets the program to Run Now. Data on a memory
preserve data card from the previously running program will be preserved if table structures have not
changed.
Copy
Copies a file, such as an Include or program support file, to the specified drive.
support files
Load OS
Loads an .obj file to the CPU drive and then loads the .obj file as the new
(File= .obj)
datalogger operating system.
Run always, Copies a program to a drive and sets the program to both Run Now and Run on Power
erase data
Up. Data on a memory card from the previously running program will be erased.
Run now,
Copies a program to a drive and sets the program to Run Now. Data on a memory card
erase data
from the previously running program will be erased.
Move file
Moves a file, such as an Include or program support file, to the specified drive.
1Use
PreserveVariables() instruction in the CRBasic program in conjunction with powerup.ini script commands 1 and 6 to
preserve data and variables.
30
Memory and Data Storage
EXAMPLE POWERUP.INI PROGRAMS
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.
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.
Example: 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.cr1x,cpu:
Example: Run Program on Power Up
'Copy program file pwrup.cr1x from the external drive to CPU:
'File will run only when the datalogger is powered-up later.
2,pwrup.cr1x,cpu:
Example: Format the USR Drive
5,,usr:
Example: Send OS on Power Up
'Load an operating system (.obj) file into FLASH as the new OS
9,CR1000X.Std.01.obj
Example: Run Program from SC115 Flash Memory Drive
'A program file is carried on an SC115 Flash Memory drive.
'Do not copy program file from SC115
'Run program always, erase data.
13,toobigforcpu.cr1x,usb:
Example: Always Run Program, Erase Data
13,pwrup_1.cr1x,cpu:
Example: Run Program Now and Erase Data Now
14,run.cr1x,cpu:
Memory and Data Storage
31
Measurements
Voltage Measurements ........................................................................................................................ 32
Current-Loop Measurements ............................................................................................................... 33
Resistance Measurements................................................................................................................... 35
Thermocouple Measurements ............................................................................................................. 40
Period-Averaging Measurements ......................................................................................................... 41
Pulse Measurements ........................................................................................................................... 41
Vibrating Wire Measurements .............................................................................................................. 46
Voltage Measurements
Voltage measurements are made using an ADC. A high-impedance programmable-gain amplifier
amplifies the signal. Internal multiplexers route individual terminals within the amplifier. The CRBasic
measurement instruction controls the ADC gain and configuration – either single-ended or differential
input. Information on the differences between single-ended and differential measurements can be found
here: "Deciding Between Single-Ended or Differential Measurements" on page 73.
A voltage measurement proceeds as follows:
1. Set PGIA gain for the voltage range selected with the CRBasic measurement instruction
parameter Range. Set the ADC for the first notch frequency selected with fN1.
2. If used, turn on excitation to the level selected with ExmV.
3. Multiplex selected terminals (InChan, SEChan, or DiffChan).
4. Delay for the entered settling time (SettlingTime).
5. Perform the analog-to-digital conversion.
6. Repeat for input reversal as determined by parameters RevEx and RevDiff.
7. Apply multiplier (Mult) and offset (Offset) to measured result.
Conceptually, analog voltage sensors output two signals: high and low. For example, a sensor that
outputs 1000 mV on the high lead and 0 mV on the low has an overall output of 1000 mV. A sensor that
outputs 2000 mV on the high lead and 1000 mV on the low also has an overall output of 1000 mV.
Sometimes, the low signal is simply sensor ground (0 mV). A single-ended measurement measures the
high signal with reference to ground, with the low signal tied to 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.
In general, use the smallest input range that accommodates the full-scale output of the sensor. This
results in the best measurement accuracy and resolution (see "Analog Measurements Specifications"
on page 88 for more information).
A set overhead reduces the chance of overrange. Overrange limits are available in the specifications.
The datalogger indicates a measurement overrange by returning a NAN for the measurement.
Warning: Sustained voltages in excess of ±20 V applied to terminals configured for analog input
will damage CR1000X circuitry.
32
Measurements
SINGLE-ENDED MEASUREMENTS
A single-ended measurement measures the difference in voltage between the terminal configured for
single-ended input and the reference ground. For example, single-ended channel 1 is comprised of
terminals SE 1 and . Single-ended terminals are labeled in blue. For more information, see "Wiring
Panel and Terminal Functions" on page 4. The single-ended configuration is used with the following
CRBasic instructions:
•
•
•
•
•
•
•
VoltSE()
BrHalf()
BrHalf3W
TCSe()
Therm107()
Therm108()
Therm109()
DIFFERENTIAL MEASUREMENTS
A differential measurement measures the difference in voltage between two input terminals. For
example, DIFF channel 1 is comprised of terminals 1H and 1L, with 1H as high and 1L as low. For more
information, see "Wiring Panel and Terminal Functions" on page 4. The differential configuration is used
with the following CRBasic instructions:
•
•
•
•
•
VoltDiff()
BrFull()
BrFull6W()
BrHalf4W()
TCDiff()
Reverse Differential
Differential measurements have the advantage of an input reversal option, RevDiff. When RevDiff
is set to 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.
Current-Loop Measurements
RG terminals can be configured to make analog current measurements using the CurrentSE()
instruction. When configured to measure current, terminals each have an internal resistance of 101 Ω
which is placed in the current measurement loop. The return path of the sensor must be connected
directly to the G terminal closest to the terminal used. The following image shows a simplified schematic
of a current measurement.
Measurements
33
EXAMPLE CURRENT-LOOP MEASUREMENT CONNECTIONS
The following table shows example schematics for connecting typical current sensors and devices.
Sensor Type
2-wire transmitter using datalogger power
2-wire transmitter using external power
3-wire transmitter using datalogger power
3-wire transmitter using external power
4-wire transmitter using datalogger power
34
Measurements
Connection Example
Sensor Type
Connection Example
4-wire transmitter using external power
See also "Current-Loop Measurements Specifications" on page 90.
Resistance Measurements
Bridge resistance is determined by measuring the difference between a known voltage applied to the
excitation (input) of a resistor bridge and the voltage measured on the output arm. The datalogger
supplies a precise voltage excitation via VX terminals. Return voltage is measured on analog input
terminals configured for single-ended (SE) or differential (DIFF) input. The result of the measurement is
a ratio of measured voltages.
See also "Resistance Measurements Specifications" on page 90.
RESISTANCE MEASUREMENTS WITH VOLTAGE EXCITATION
CRBasic instructions for measuring resistance with voltage excitation include:
• BrHalf() - half bridge
• BrHalf3W() - three-wire half bridge
• BrHalf4W() - four-wire half bridge
• BrFull() - four-wire full bridge
• BrFull6W() - six-wire full bridge
Resistive-Bridge Type and
Circuit Diagram
CRBasic Instruction and
Fundamental Relationship
Half Bridge1
CRBasic Instruction: BrHalf()
Relational Formulas
Fundamental Relationship:
Measurements
35
Resistive-Bridge Type and
Circuit Diagram
CRBasic Instruction and
Fundamental Relationship
Three Wire Half Bridge1,2
CRBasic Instruction: BrHalf3W()
Relational Formulas
Fundamental Relationship:
Four Wire Half Bridge1,2
CRBasic Instruction: BrHalf4W()
Fundamental Relationship:
Full Bridge1,2
CRBasic Instruction: BrFull()
Fundamental Relationship:
36
Measurements
These relationships apply
to BrFull()
and BrFull6W()
Resistive-Bridge Type and
Circuit Diagram
CRBasic Instruction and
Fundamental Relationship
Six Wire Full Bridge1
CRBasic Instruction: BrFull6W()
Relational Formulas
Fundamental Relationship:
1Key:
Vx = excitation voltage; V1, V2 = sensor return voltages; Rf = fixed, bridge or completion resistor; Rs = variable or sensing
resistor.
2Campbell Scientific offers a list of available terminal input modules to facilitate this measurement.
Offset voltage compensation applies to bridge measurements. In addition to RevDiff and MeasOff
parameters discussed in "Minimizing Offset Voltages" on page 80, 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, RevEx, and MeasOff 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 four-wire 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. The results of measurement instructions (X) must then be processed further to obtain the
resistance value, which requires additional program execution time.
CRBasic Example: 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 X_1
Measurements
37
Public
Public
Public
Public
R_1
R_2 = 1000 'Resistance of fixed resistor R2
R_3 = 1000 'Resistance of fixed resistor R2
R_4 = 1000 'Resistance of fixed resistor R4
'Main Program
BeginProg
Scan(500,mSec,1,0)
'Full Bridge Measurement:
BrFull(X,1,mV200,1,Vx1,1,4000,True,True,0,60,1.0,0.0)
X_1 = ((-1 * X) / 1000) + (R_3 / (R_3 + R_4))
R_1 = (R_2 * (1 - X_1)) / X_1
NextScan
EndProg
STRAIN MEASUREMENTS
A principal use of the four-wire full bridge is the measurement of strain gages in structural stress
analysis. StrainCalc() calculates microstrain (µɛ) 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 following table 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. A dashed code sets the polarity of Vr
to negative.
StrainCalc()
BrConfig
Code
Configuration
Quarter-bridge strain gage1:
1
Half-bridge strain gage1. One gage parallel to strain, the other at 90° to strain:
2
Half-bridge strain gage. One gage parallel to +ɛ, the other parallel to -ɛ1:
3
38
Measurements
StrainCalc()
BrConfig
Code
Configuration
Full-bridge strain gage. Two gages parallel to +ɛ, the other two parallel to -ɛ1:
4
Full-bridge strain gage. Half the bridge has two gages parallel to +ɛ and -ɛ, and the other
half to +ⱱɛ and -ⱱɛ 1:
5
Full-bridge strain gage. Half the bridge has two gages parallel to +ɛ and -ⱱɛ , and the other
half to -ⱱɛ and +ɛ1:
6
1Where
•
•
•
•
ⱱ : 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:
• "source": the result of the full-bridge measurement (X = 1000 • V1 / Vx) when multiplier = 1 and offset = 0.
• "zero": gage offset to establish an arbitrary zero.
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 also "Minimizing Ground Loop Errors" on page 71.
Measurements
39
ACCURACY FOR RESISTANCE MEASUREMENTS
Consult the following technical papers for in-depth treatments of several topics addressing voltage
measurement quality:
• Preventing and Attacking Measurement Noise Problems
• Benefits of Input Reversal and Excitation Reversal for Voltage Measurements
• Voltage Measurement Accuracy, Self- Calibration, and Ratiometric Measurements
Note: Error discussed in this section and error-related specifications of the CR1000X do not
include error introduced by the sensor or by the transmission of the sensor signal to the
datalogger.
For accuracy specifications for ratiometric resistance measurements, see "Resistance Measurements
Specifications" on page 90. Voltage measurement is variable V1 or V2 in "Resistance Measurements"
on page 35. Offset is the same as that for simple analog voltage measurements.
Assumptions that support the ratiometric-accuracy specification include:
• Datalogger is within factory calibration specification.
• Input reversal for differential measurements and excitation reversal for excitation voltage are
within specifications.
• Effects due to the following are not included in the specification:
o Bridge-resistor errors
o Sensor noise
o Measurement noise
Thermocouple Measurements
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.
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 datalogger. 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 datalogger 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 reference junction temperature provides the determination of a reference junction
compensation voltage, corresponding to the temperature difference between the reference junction and
0°C. This compensation voltage, combined with the measured thermocouple voltage, can be used to
compute the absolute temperature of the thermocouple junction.
40
Measurements
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 0°C. If the reference junction is the datalogger analog-input terminals, the
temperature is conveniently measured with the PanelTemp() instruction. The actual thermocouple
voltage is measured and combined with the reference junction compensation voltage. It is then used to
determine the thermocouple-junction temperature based on a polynomial approximation of NIST
thermocouple calibrations.
Period-Averaging Measurements
Period-averaging measurements are used to measure the period or frequency of a signal. For these
measurements, the datalogger uses 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
than pulse-count measurements. See also "Pulse Measurements" on page 41.
SE terminals on the datalogger are configurable for measuring the period of a signal.
The measurement is performed as follows: 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
for additional input conditioning circuitry. The threshold allows direct connection of standard digital
signals, but it is not recommended for small-amplitude sensor signals.
A threshold other than zero results in offset voltage drift, limited accuracy (≈±10 mV) and limited
resolution (≈1.2 mV).
See also "Period-Averaging Measurements Specifications" on page 90.
Tip: Both pulse count and period-average measurements are used to measure frequency output
sensors. However, their measurement methods are different. Pulse count measurements use dedicated
hardware - pulse count accumulators, which are always monitoring the input signal, even when the
datalogger is between program scans. In contrast, period-average measurements use program
instructions that only monitor the input signal during a program scan. Consequently, pulse count scans
can occur less frequently than period-average scans. Pulse counters may be more susceptible to lowfrequency noise because they are always "listening", whereas period-averaging measurements 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.
Pulse Measurements
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 datalogger 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. Both pulse count
and period-average measurements are used to measure frequency-output sensors. For more
information, see "Period-Averaging Measurements" on page 41.
Measurements
41
The datalogger includes terminals that are configurable for pulse input to measure counts or frequency
as shown in the following image.
Pulse input terminals and the input types they can measure
Input Type
Pulse Input Terminal
High-frequency
Low-level ac
Switch-closure
P1
P2
C (all)
P1
P2
P1
P2
C (all)
Data Option
• Counts
• Frequency
• Running average of
frequency
Using the PulseCount() instruction, P and C terminals are configurable for pulse input to measure
counts or frequency. Maximum input frequency is dependent on input voltage (see "Pulse
Measurements Specifications" on page 91 for more information). If pulse input voltages exceed the
maximum voltage, third-party external-signal conditioners should be employed. Under no
circumstances should voltages greater than 20 V be measured.
Terminals configured for pulse input have internal filters that reduce electronic noise, and thus reduce
false counts. Internal ac coupling is used to eliminate dc offset voltages. For tips on working with pulse
measurements, see "Pulse Measurement Tips" on page 45.
For more information, see "Pulse Measurements Specifications" on page 91.
LOW-LEVEL AC MEASUREMENTS
Low-level ac (sine-wave) signals can be measured on P terminals. Ac generator anemometers typically
output low-level ac.
Measurements include the following:
• 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.
CRBasic instruction: PulseCount()
42
Measurements
Low-level ac signals cannot be measured directly by C terminals. Peripheral terminal expansion
modules are available for converting low-level ac signals to square-wave signals measurable by C
terminals.
For more information, see "Pulse Measurements Specifications" on page 91.
HIGH FREQUENCY MEASUREMENTS
High-frequency (square-wave) signals can be measured on P or C terminals. Common sensors that
output high-frequency include:
• Photo-chopper anemometers
• Flow meters
Measurements include counts, frequency in hertz, and running average. Note that the resolution of a
frequency measurement can be different depending on whether the measurement is made with the
PulseCount()or TimerInput() instruction. See the CRBasic help for more information.
The datalogger has built-in pull-up and pull-down resistors for different pulse measurements which can
be accessed using the PulseCount() instruction. Note that pull down options are usually used for
sensors that source their own power.
P Terminals
• CRBasic instructions: PulseCount()
High-frequency pulse inputs are routed to an inverting CMOS input buffer with input hysteresis.
C Terminals
• CRBasic instructions: PulseCount(), TimerInput()
SWITCH-CLOSURE AND OPEN-COLLECTOR MEASUREMENTS
Switch-closure and open-collector signals can be measured on P or C terminals. Mechanical switchclosures have a tendency to bounce before solidly closing. Unless filtered, bounces can cause multiple
counts per event. The datalogger automatically filters bounce. Because of the filtering, the maximum
switch-closure frequency is less than the maximum high-frequency measurement frequency. Sensors
that commonly output a switch-closure or open-collector signal include:
• Tipping-bucket rain gages
• Switch-closure anemometers
• Flow meters
The datalogger has built-in pull-up and pull-down resistors for different pulse measurements which can
be accessed using the PulseCount() instruction. Note that pull down options are usually used for
sensors that source their own power.
Data output options include counts, frequency (Hz), and running average.
Measurements
43
P Terminals
An internal 100 kΩ pull-up resistor pulls an input to 5 Vdc with the switch open, whereas a switchclosure to ground pulls the input to 0 V.
• CRBasic instruction: PulseCount()
Switch Closure on P Terminal
Open Collector on P Terminal
C Terminals
Switch-closure mode is a special case edge-count function that measures dry-contact switch-closures
or open collectors. The operating system filters bounces.
• CRBasic instruction: PulseCount()
See also "Pulse Measurements Specifications" on page 91.
EDGE TIMING AND EDGE COUNTING
Edge time, period, and counts can be measured on P or C terminals. Measurements for feedback
control using pulse-width modulation (PWM) are an example of an edge timing application.
Single Edge Timing
A single edge or state transition can be measured on P or C terminals. Measurements can be
expressed as a frequency (Hz) or period (µs):
CRBasic instructions:
• TimerInput() – available on C1–C8
• PulseCount() – available on C1–C8 and P1–P2
• PeriodAvg() – available on SE1–SE16
Multiple Edge Counting
Time between edges, time from an edge on the previous channel, and edges that span the scan interval
can be measured on C terminals:
• CRBasic instruction: TimerInput()- available on C1–C8
44
Measurements
Timer Input on NAN Conditions
NAN is the result of a TimerInput() measurement if one of the following occurs:
• Measurement timer expires.
• The signal frequency is too fast.
For more information, see:
• "Pulse Measurements Specifications" on page 91
• "Digital Input/Output Specifications" on page 91
• "Period-Averaging Measurements Specifications" on page 90
PULSE MEASUREMENT TIPS
The PulseCount() instruction uses dedicated 32-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
4,294,967,296 (232), resulting in erroneous measurements.
• 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) so are usually
measured using the PulseCount() frequency-output option.
• Use the LLAC4 module to convert non-TTL-level signals, including low-level ac signals, to TTL
levels for input into C terminals.
Conflicts can occur when companion ports are used for different instructions (TimerInput,
PulseCount, SDI12Recorder, WaitDigTrig). For example, if C1 is used for the SDI12Recorder
instruction, C2 cannot be used in the TimerInput, PulseCount, or WaitDigTrig instructions.
Understanding the signal to be measured and compatible input terminals and CRBasic instructions is
helpful. See "Pulse input terminals and the input types they can measure" on page 42.
Input Filters and Signal Attenuation
Terminals configured for pulse input have internal filters that reduce electronic noise. The electronic
noise can result in false counts. However, input filters attenuate (reduce) the amplitude (voltage) of the
signal. Attenuation is a function of the frequency of the signal. Higher-frequency signals are attenuated
more. If a signal is attenuated enough, it may not pass the detection thresholds required by the pulse
count circuitry. See "Pulse Measurements Specifications" on page 91 for more information. The listed
pulse measurement specifications account for attenuation due to input filtering.
While a C terminal measured with the TimerInput() frequency measurement may be superior for
clean signals, a P terminal filter (much higher τ) may be required to get a measurement on an
electronically noisy signal.
For example, 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 low-amplitude signals.
• 1 ms time-constant (159 Hz 3 dB frequency) for larger (> 0.7 V) amplitude signals.
Measurements
45
Pulse Count Resolution
Longer scan intervals result in better resolution. PulseCount() resolution is 1 pulse per scan. On a 1
second scan the resolution is 1 pulse per second. The resolution on a 10 second scan interval is 1
pulse per 10 seconds, which is 0.1 pulses per second. The resolution on a 100 millisecond interval is 10
pulses per second.
For example, if a flow sensor outputs 4.5 pulses per second and you use a 1 second scan, one scan will
have 4 pulses and the next 5 pulses. Scan to scan, the flow number will bounce back and forth. If you
did a 10 second scan (or saved an average to a 10 second table), you would get 45 pulses. The
average is 45 pulses for every 10 seconds. The average will correctly show 4.5 pulses per second. You
wouldn't see the reading bounce on the longer time interval.
Vibrating Wire Measurements
The datalogger can measure vibrating wire sensors through vibrating-wire interface modules. Vibrating
wire sensors are the sensor of choice in many environmental and industrial applications that need
sensor stability over very long periods, such as years or even decades. A thermistor included in most
sensors can be measured to compensate for temperature errors.
VSPECT
Measuring the resonant frequency by means of period averaging is the classic technique, but Campbell
Scientific has developed static and dynamic spectral-analysis techniques (VSPECT) that produce
superior noise rejection, higher resolution, diagnostic data, and, in the case of dynamic VSPECT,
measurements up to 333.3 Hz. For detailed information on VSPECT, see Vibrating Wire Spectral
Analysis Technology.
46
Measurements
Communication Protocols
Dataloggers communicate with datalogger support software and other Campbell Scientific dataloggers
using a number of protocols including PakBus®, Modbus, DNP3, CPI, SPI, and TCP/IP. Several
industry-specific protocols are also supported. CAN bus is supported when using the Campbell
Scientific SDM-CAN communication module. See also "Communications Specifications" on page 92.
General Serial Communications .......................................................................................................... 47
Modbus Communications .................................................................................................................... 48
Internet Communications ..................................................................................................................... 49
DNP3 Communications........................................................................................................................ 49
PakBus Communications ..................................................................................................................... 50
SDI-12 Communications ...................................................................................................................... 50
Serial Peripheral Interface (SPI) and I2C ............................................................................................. 54
Some communication services, such as satellite networks, can be expensive to send and receive
information. Best practices for reducing expense include:
• Declare Public only those variables that need to be public. Other variables should be declared as
Dim.
• Be conservative with use of string variables and string variable sizes. Make string variables as big
as they need to be and no more. The default size, if not specified, is 24 bytes, but the minimum is
4 bytes. Specify the size if 24 bytes of possibly unused space is not desired. 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 datalogger to be a PakBus router only as needed. When the datalogger 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. Network Planner set this
appropriately when it is used. This is also set through the IsRouter setting in the Settings Editor.
• 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. Network Planner will set
this appropriately when it is used. This is also set through the Beacon and Verify settings in the
Settings Editor.
For information on Designing a PakBus network using the Network Planner tool in LoggerNet, watch
a video.
General Serial Communications
The datalogger supports two-way serial communication. These communication ports can be used with
smart sensors that deliver measurement data through serial data protocols or with devices, such as
modems, that communicate using serial data protocols. See "Communication Ports" on page 8 for
information on port configuration options.
Communication Protocols
47
CRBasic instructions for general serial communications include:
• SerialOpen()
• SerialClose()
• SerialIn()
• SerialInRecord()
• SerialInBlock()
• SerialOut()
• SerialOutBlock()
To communicate over a serial port, it is important to be familiar with the protocol of the sensor or device.
Refer to the manual of the sensor or device to find its protocol and then select the appropriate options
for each CRBasic parameter. See the application note Interfacing Serial Sensors with Campbell
Scientific Dataloggers for more programming details and examples.
Modbus Communications
The datalogger supports Modbus RTU, Modbus ASCII, and Modbus TCP protocols and can be
programmed as a Modbus master or Modbus slave. These protocols are often used in Modbus SCADA
networks. Dataloggers can communicate with Modbus on all available communication ports. The
datalogger supports RTU and ASCII communication modes on RS-232 and RS-485 connections.
CRBasic Modbus instructions include (see CRBasic Editor help for the most recent information on each
of these instructions and for program examples):
• ModbusMaster()
• ModbusSlave()
• MoveBytes()
For additional information on Modbus, see:
• Why Modbus Matters: An Introduction
• How to Access Live Measurement Data Using Modbus
• Using Campbell Scientific Dataloggers as Modbus Slave Devices in a SCADA Network
Because Modbus has a set command structure, programming the datalogger 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 datalogger without additional
hardware.
A datalogger goes into sleep mode after 40 seconds of communication inactivity. Once asleep, two
packets are required before it will respond. The first packet awakens the datalogger; the second packet
is received as data. This would make a Modbus master fail to poll the datalogger, if not using retries.
The datalogger, through Device Configuration Utility or the Status table, can be set to keep
communication ports open and awake, but at higher power usage.
Further information on Modbus can be found at:
• www.simplyModbus.ca/FAQ.htm
• www.Modbus.org/tech.php
• www.lammertbies.nl/comm/info/modbus.html
48
Communication Protocols
Internet Communications
See the "Communications Specifications" on page 92 for a list of the internet protocols supported by the
datalogger.
CRBasic instructions for internet communications include:
•
•
•
•
•
•
•
EmailRelay()
EmailSend()
EmailRecv()
FTPClient()
HTTPGet()
HTTPOut()
HTTPPost()
•
•
•
•
•
•
HTTPPut
IPInfo()
PPPOpen()
PPPClose()
TCPOpen()
TCPClose()
Once the hardware has been configured, basic PakBus® communication over TCP/IP is possible.
These functions include the following:
• Sending programs
• Retrieving programs
• Setting the datalogger 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-to-datalogger communications, consult your
network link manual (see www.campbellsci.com/internet-ip-networks).
IP ADDRESS
When connected to a server with a list of IP addresses available for assignment, the datalogger will
automatically request and obtain an IP address through DHCP. Once the address is assigned, look in
the Settings Editor: Ethernet | {information box} to see the assigned IP address.
The CR1000X provides a 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.
HTTPS
The datalogger has the ability to act as an HTTPS server. This can be configured using Device
Configuration Utility.
DNP3 Communications
DNP3 is designed to optimize transmission of data and control commands from a master computer to
one or more remote devices or outstations. The datalogger allows DNP3 communication on all available
communication ports. CRBasic DNP3 instructions include:
• DNP()
• DNPUpdate()
• DNPVariable()
Communication Protocols
49
See the CRBasic help for detailed information and program examples.
For additional information on DNP3 see:
• DNP3 with Campbell Scientific Dataloggers
• Getting to Know DNP3
• How to Access Your Measurement Data Using DNP3
PakBus Communications
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 datalogger.
The datalogger allows PakBus communication on all available communication ports. For additional
information, see The Many Possibilities of PakBus Networking.
Advantages of PakBus are as follows:
• Simultaneous communication between the datalogger and other devices.
• Peer-to-peer communication - no computer 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 datalogger.
• Routing - the datalogger can act as a router, passing on messages intended for another
Campbell Scientific datalogger. PakBus supports automatic route detection and selection.
• Short distance networks - a datalogger can talk to another datalogger 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 datalogger, the datalogger support software must know the
datalogger PakBus address. The PakBus address is changed using Device Configuration Utility,
datalogger Status table, Settings Editor, or PakBus Graph software.
CRBasic PakBus instructions include:
• GetDataRecord()
• GetVariables()
• SendData()
• SendGetVariables()
• SendVariables()
SDI-12 Communications
SDI-12 is a 1200 baud protocol that supports many smart sensors. The datalogger supports SDI-12
communication through two modes — transparent mode and programmed mode (see "SDI-12 Port" on
page 9 for wiring terminal information). Conflicts can occur when companion ports are used for different
instructions (TimerInput, PulseCount, SDI12Recorder, WaitDigTrig). For example, if C1 is
50
Communication Protocols
used for the SDI12Recorder instruction, C2 cannot be used in the TimerInput, PulseCount, or
WaitDigTrig instructions.
• 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.
See "SDI-12 Transparent Mode" on page 51 for more information.
• Programmed mode automates much of the SDI-12 protocol and provides for data recording. See
"SDI-12 Programmed Mode/Recorder Mode" on page 52 for more information.
CRBasic SDI-12 instructions include:
• SDI12Recorder()
• SDI12SensorSetup()
• SDI12SensorResponse()
• SDI12Watch()
When the datalogger is used as a sensor (using SDI12SensorSetup() and
SDI12SensorResponse() instructions), SDI-12 version 1.4 is used. When the datalogger is used as
a recorder (using SDI12SensorResponse() instruction), SDI-12 version 1.3 is used.
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, the datalogger programs may not execute. Datalogger
security may need to be unlocked before transparent mode can be activated.
Transparent mode is entered while the computer is in communication with the datalogger through a
terminal emulator program. It is easily accessed through a terminal emulator available with Device
Configuration Utility and other datalogger support software. Keyboard displays cannot be used. For
how-to instructions for communicating directly with an SDI-sensor using a terminal emulator, watch
this video.
To enter the SDI-12 transparent mode, enter the datalogger support software terminal emulator:
1. Press Enter until the datalogger responds with the prompt CR1000X>.
2. Type SDI12 at the prompt and press Enter.
3.
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, and press Enter. For
example, 1 is entered for terminal C1.
4.
An Entering SDI12 Terminal response indicates that SDI-12 transparent mode is active
and ready to transmit SDI-12 commands and display responses.
Communication Protocols
51
The terminal-mode utility allows monitoring of SDI-12 traffic by using the watch command (sniffer
mode). Watch an instructional this video or use the following instructions.
1. Enter the terminal mode as described previously.
2. Press Enter until a CR1000X> prompt appears.
3. Type W and then press Enter.
4. In response, the query Select: is presented with a list of available ports. Enter the port number
assigned to the terminal to which the SDI-12 sensor is connected, and press Enter.
5. In answer to Enter timeout (secs): type 100 and press Enter.
6. In response to the query ASCII (Y)?, type Y and press Enter.
7. SDI-12 communications are then opened for viewing.
SDI-12 Transparent Mode Commands
SDI-12 commands and responses are defined by the SDI-12 Support Group (www.sdi-12.org) and are
available in the SDI-12 Specification. Sensor manufacturers determine which commands to support.
Commands have three components:
• Sensor address (a): A single character and the first character of the command. Sensors are
usually assigned a default address of zero by the manufacturer. The wildcard address (?) is used
in the Address Query command. Some manufacturers may allow it to be used in other
commands. SDI-12 sensors accept addresses 0 through 9, a through z, and A through Z.
• 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 PROGRAMMED MODE/RECORDER MODE
The datalogger can be programmed to act as an SDI-12 data recorder or as an SDI-12 sensor using a
terminal configured for SDI-12. The SDI12Recorder() instruction automates sending commands and
recording responses. With this instruction, the commands to poll sensors and retrieve data are done
automatically with proper elapsed time between the two. The datalogger automatically issues retries.
See CRBasic Editor help for more information on this instruction.
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
datalogger 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 datalogger issues the aM! and aD0! commands with proper
elapsed time between the two. The datalogger automatically issues retries and performs other services
that make the SDI-12 measurement work as trouble free as possible.
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.
52
Communication Protocols
PROGRAMMING THE DATALOGGER TO ACT AS AN SDI-12 SENSOR
The SDI12SensorSetup() / SDI12SensorResponse() instruction pair programs the datalogger to
behave as an SDI-12 sensor. A common use of this feature is the transfer of data from the datalogger 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.
When programmed as an SDI-12 sensor, the datalogger will respond to SDI-12 commands M, MC, C, CC,
R, RC, V, ?, and I. The following rules apply:
A datalogger can be assigned only one SDI-12 address per SDI-12 port. For example, a datalogger 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.
SDI-12 POWER CONSIDERATIONS
When a command is sent by the datalogger 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:
• Quiescent: 0.25 mA
• Active: 66 mA
• Measurement: 120 mA
Measurement time: 15 s
Timeout: 15 s
Probes 1, 2, 3, and 4 are connected to SDI-12 port C1.
The time line in the following table 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 helps reduce power consumption.
Example Power Usage Profile for a Network of SDI-12 Probes:
Time into
Measurement
Processes
Sleep
1
2–14
15
16
17-29
30
Sleep
Command
All Probes Time Out Probe 1 Probe Probe Probe
Awake
Expires
(mA) 2 (mA) 3 (mA) 4 (mA)
Total
(mA)
0.25
120
120
120
66
66
66
0.25
1
318
318
318
264
264
264
1
1M!
Yes
1D0!
Yes
Yes
Yes
0.25
66
66
66
66
66
66
0.25
0.25
66
66
66
66
66
66
0.25
0.25
66
66
66
66
66
66
0.25
Communication Protocols
53
Serial Peripheral Interface (SPI) and I2C
Serial Peripheral Interface is a clocked synchronous interface, used for short distance communications,
generally between embedded devices. I2C is a multi-master, multi-slave, packet switched, singleended, serial computer bus. I2C is typically used for attaching lower-speed peripheral ICs to processors
and microcontrollers in short-distance, intra-board communication. I2C and SPI are protocols supported
by the operating system. See CRBasic Editor help for instructions that support these protocols.
For additional information on I2C, see www.i2c-bus.org.
54
Communication Protocols
Maintaining Your Datalogger
Protect the datalogger from humidity and moisture. When humidity levels reach the dewpoint,
condensation occurs, and damage to datalogger electronics can result. Adequate desiccant should be
placed in the instrumentation enclosure to provide protection and control humidity, and it should be
changed periodically.
If sending the datalogger to Campbell Scientific for calibration or repair, consult first with Campbell
Scientific. If the datalogger is malfunctioning, be prepared to perform some troubleshooting procedures
(see "Tips and Troubleshooting" on page 65). Many problems can be resolved with a telephone
conversation. If calibration or repair is needed, the procedure shown on:
https://www.campbellsci.com/repair should be followed when sending the product.
Datalogger Calibration ......................................................................................................................... 55
Datalogger Security ............................................................................................................................. 56
Datalogger Enclosures......................................................................................................................... 59
Internal Battery .................................................................................................................................... 59
Electrostatic Discharge and Lightning Protection ................................................................................. 61
Power Budgeting ................................................................................................................................. 62
Updating the Operating System ........................................................................................................... 62
Datalogger Calibration
Campbell Scientific recommends factory recalibration every three years. During calibration, all the input
terminals, peripheral and communications terminals, operating system, and memory areas are
checked; and the internal battery is replaced. The datalogger is checked to ensure that all hardware
operates within published specifications before it is returned. To request recalibration for a product, see
www.campbellsci.com/repair.
It is recommended that you maintain a level of calibration appropriate to the application of the
datalogger. Consider the following factors when setting a calibration schedule:
• The importance of the measurements.
• How long the datalogger will be used.
• The operating environment.
• How the datalogger will be handled.
See also "About Background Calibration" on page 55.
You can download and print calibration certificates for many products you have purchased by logging in
to the Campbell Scientific website and going to: https://www.campbellsci.com/calcerts. Note, you will
need your product's serial number to access its certificate. Watch an instructional video.
ABOUT BACKGROUND CALIBRATION
The datalogger uses an internal voltage reference to routinely self-calibrate to compensate for changes
caused by changing operating temperatures and aging. Background calibration calibrates only the
coefficients necessary to run the current CRBasic program. These coefficients are reported in the
Status table as CalVolts(), CalGain(), CalOffset(), and CalCurrent().
Maintaining Your Datalogger
55
Auto background calibration will be disabled automatically when the scan rate is too high for the
background calibration measurements to occur in addition to the measurements contained within the
program. The Calibrate() instruction can be used to override or disable background calibration.
Disable this background calibration when it interferes with execution of very fast programs and less
accuracy can be tolerated. With background 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 –55 °C to 85 °C, the accuracy specification of ±0.08 % of reading can degrade to
±0.8 % of reading with background calibration disabled. If the temperature of the datalogger remains
the same, there is little calibration drift if background calibration is disabled.
Datalogger Security
Datalogger security concerns include:
• Collection of sensitive data
• Operation of critical systems
• Networks accessible by many individuals
Some options to secure your datalogger from mistakes or tampering include:
• Sending the latest operating system to the datalogger. See "Updating the Operating System" on
page 62 for more information.
• Disabling unused services and securing those that are used. This includes disabling HTTP,
HTTPS, FTP, Telnet, and Ping network services (Device Configuration Utility | Settings Editor |
Network Services tab). These services can be used to discover your datalogger on an IP network.
• Setting security codes (see following information under "Security Codes").
• Setting a PakBus/TCP password. The PakBus TCP password controls access to PakBus
communication over a TCP/IP link. PakBusTCP passwords can be set in Device Configuration
Utility.
• Disabling FTP or setting an FTP username and password in Device Configuration Utility.
• Setting a PakBus encryption (AES-128) key in Device Configuration Utility. This forces PakBus
data to be encrypted during transmission.
• Disabling HTTP/HTTPS or creating a .csipasswd file to secure HTTP/HTTPS (see "Creating a
.csipasswd File" on page 57 for more information).
• Enabling HTTPS and disabling HTTP. To prevent data collection via the web interface, both
HTTP and HTTPS must be disabled.
• Tracking Operating System, Run, and Program signatures.
• Encrypting program files if they contain sensitive information (see CRBasic help
FileEncrypt() instruction or use the CRBasic Editor File menu, Save and Encrypt option).
• Hiding program files for extra protection (see CRBasic help FileManage() instruction).
• Securing the physical datalogger and power supply under lock and key.
• Monitoring your datalogger for changes by tracking program and operating system signatures, as
well as CPU, USR, and CRD file contents.
Warning: All security features can be subverted through physical access to the datalogger. If
absolute security is a requirement, the physical datalogger must be kept in a secure location.
56
Maintaining Your Datalogger
SECURITY CODES
The datalogger employs a security scheme that includes three levels of security. Security codes can
effectively lock out innocent tinkering and discourage wannabe hackers on all communication links.
However, any serious hacker with physical access to the datalogger or to the communications hardware
can, with only minimal trouble, overcome the five-digit security codes.
Methods of enabling security codes include the following:
• Device Configuration Utility: Security codes are set on the Deployment | Datalogger tab.
• SetSecurity() instruction in CRBasic: SetSecurity() is only executed at program compile
time.
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.
Up to three levels of security codes can be set. Valid security codes are 1 through 65535 (0 confers no
security). Security 1 must be set before Security 2. Security 2 must be set before Security 3. If any one
of the codes is set to 0, any security code level greater than it will be set to 0. For example, if Security 2
is 0 then Security 3 is automatically set to 0. Security codes are unlocked in reverse order: Security 3
before Security 2, Security 2 before Security 1.
Functions affected by each level of security are:
• Security 1: Collecting data, setting the clock, and setting variables in the Public table are
unrestricted, requiring no security code. If Security 1 code is entered, read/write values in the
Status, Settings, and DataTableInfo tables can be changed; fields can be edited in the
ConstTable; and the datalogger program can be changed or retrieved.
• Security 2: Data collection is unrestricted, requiring no security code. If the user enters the
Security 2 code, the datalogger clock can be changed, values in the Public table can be changed,
and read/write DataTable Sample fields can be edited.
• Security 3: When this level is set, all communication with the datalogger is prohibited if no
security code is entered. If Security 3 code is entered, data can be viewed and collected from the
datalogger (except data suppressed by the TableHide() instruction).
For additional information on datalogger security, see:
• 4 Ways to Make your Data More Secure
• Available Security Measures for Internet-Connected Dataloggers
• How to Use Datalogger Security Codes
• How Can Data be Made More Secure on a CRBasic PakBus Datalogger
CREATING A .CSIPASSWD FILE
The datalogger employs a security scheme that includes three levels of security (see "Datalogger
Security" on page 56 for more information). This scheme can be used to limit access to a datalogger
that is publicly available. However, the security code is visible in Device Configuration Utility. In
addition, the range of codes is relatively small. To provide a more robust means of security, Basic
Access Authentication was implemented with the HTTP API interface in the form of an encrypted
password file named .csipasswd. In order to provide read/write access to the web interface, you must
create a .csipasswd file. This file is also used to access the embedded web interface, which provides
Maintaining Your Datalogger
57
access to real-time and stored datalogger data. For more information on the web interface, watch an
instructional video.
When a file named .csipasswd is stored on the datalogger's CPU drive, basic access authentication
is enabled in the datalogger and read/write access to the web interface can be defined. Multiple user
accounts/levels of access can be defined for one datalogger. Four levels of access are available:
• None: Disable a user account.
• Read Only: Data collection is unrestricted and available. Clock and writable variables cannot be
changed; programs cannot be viewed, stopped, deleted, or retrieved.
• Read/Write: Data collection is unrestricted and available, and clock and writable variables can be
changed. Programs cannot be viewed, stopped, deleted, or retrieved.
• All: Data collection is unrestricted and available, clock and writable variables can be changed;
and programs can be viewed, stopped, deleted and retrieved.
Note: All levels of access allow data collection.
Create an encrypted password file or modify an existing password file using Device Configuration
Utility:
1. Connect to your device in Device Configuration Utility.
2. Click the Network Services tab, then click the Edit .csipasswd File button.
3. Define your user accounts and access levels.
4. Click Apply. The .csipasswd file is automatically saved to the datalogger’s CPU drive.
When a .csipasswd file enables basic access authentication, the datalogger's PakBus/TCP Password
security setting is not used when accessing the datalogger via HTTP. If the .csipasswd file is blank or
does not exist, the default user name is "anonymous" with no password and a user level of read only.
When access to the datalogger web server is attempted without the appropriate security level, the
datalogger will prompt the web client to display a user name/password request dialog. If an invalid
username or password is entered, the datalogger web server will default to the level of access assigned
to “anonymous”. As noted above, anonymous is assigned a user level of read-only, though this can be
changed using Device Configuration Utility.
If the numeric security code has been enabled using Device Configuration Utility, the SetSecurity()
instruction, or the Security() Status table settings, and no .csipasswd file is on the datalogger, then
that numeric security code must be entered to access the datalogger. If a .csipasswd file is on the
datalogger, the User Name and Password employed by the Basic Access Authentication will eliminate
the need for entering the numeric security code.
Command Syntax
Syntax for the commands sent to the web server generally follows the form of:
URL?command=CommandName&uri=DataSource&arguments
Arguments are appended to the command string using an ampersand (&). Some commands have
optional arguments, where omitting the argument results in a default being used. When applicable,
optional arguments and their defaults are noted and examples are provided in the CRBasic help
(search Web Server/API Commands).
58
Maintaining Your Datalogger
Datalogger Enclosures
The datalogger and most of its peripherals must be protected from moisture and humidity. Moisture in
the electronics will seriously damage the datalogger. In most cases, protection from moisture is easily
accomplished by placing the datalogger in a weather-tight enclosure with desiccant and elevating the
enclosure above the ground. Desiccant in enclosures should be changed periodically.
Warning: 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.
The following details a typical installation using a Campbell Scientific enclosure. The datalogger has
mounting holes through which small screws are inserted into nylon anchors in the backplate.
1. Insert the included nylon anchors into the backplate. Position them to align with the mounting
holes on the base of the CR1000X.
2. Holding the CR1000X to the backplate, screw the screws into the nylon anchors.
See also "Physical Specifications" on page 85.
Internal Battery
The lithium battery powers the internal clock and SRAM when the datalogger is not powered. This
voltage is displayed in the LithiumBattery field in the Status table. Replace the battery when voltage is
approximately 2.7 Vdc. The internal lithium battery has a three-year life when no external power source
is applied. Its life is extended when the datalogger is installed with an external power source. If the
datalogger is used in a high-temperature application, the battery life is shortened.
Note: The Status field Battery value and the destination variable from the Battery() instruction
(often called batt_volt) in the Public table reference the external battery voltage.
To prevent clock and memory issues, it is recommended you proactively replace the battery every 2-3
years, or more frequently when operating continuously in high temperatures.
Note: The battery is replaced during regular factory recalibration, which is recommended every 3
years. For more information, see "Datalogger Calibration" on page 55.
When the lithium battery is removed (or is depleted and primary power to the datalogger is removed),
the CRBasic program and most settings are maintained, but the following are lost:
• 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. See
"Power Requirements" on page 85 for more information.
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.
Maintaining Your Datalogger
59
INTERNAL LITHIUM BATTERY SPECIFICATIONS
• Manufacturer: Tadiran
• Tadiran Model Number: TL-5903/S
• Voltage: 3.6 V
• Capacity: 2.4 Ah
• Self-discharge Rate: 1%/year @ 20 °C
• Operating Temperature Range: –55 to 85 °
REPLACING THE INTERNAL BATTERY
It is recommended that you send the datalogger in for scheduled calibration, which includes internal
battery replacement (see "Datalogger Calibration" on page 55).
Warning: Any damage made to the datalogger during replacement of the internal battery is not
covered under warranty.
1. Remove the two screws from the back of the panel.
2. Pull one edge of the canister away from the wiring panel to loosen it from the internal connector
seatings.
3. Lift the canister edge out of the enclosure tabs.
4. Remove the nuts, then open the clam shell.
60
Maintaining Your Datalogger
5. Remove the lithium battery by gently prying it out with a small slot head screwdriver.
6. Reassemble the datalogger. Take particular care to ensure the canister is reseated tightly into the
connectors by firmly pressing them together by hand.
Electrostatic Discharge and Lightning Protection
Warning: Lightning strikes may damage or destroy the datalogger and associated sensors and
power supplies.
Electrostatic discharge (ESD) can originate from several sources, the most common and destructive
being 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 lightning rod, metal mast, heavy-gauge ground wire, and ground
rod to direct damaging current away from the datalogger. This system, however, is not infallible. The
following image displays a typical application of the system:
Maintaining Your Datalogger
61
All critical inputs and outputs on the datalogger are ESD protected to 75 V. To be effective, the earth
ground lug must be properly connected to earth (chassis) ground.
Communication ports are another path for transients. You should provide communication paths, such
as telephone or short-haul modem lines, with spark-gap 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.
For detailed information on grounding, see "Grounds" on page 7.
Power Budgeting
In low-power situations, the datalogger 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-Vdc wall adapter, the
onboard charging regulator, and a rechargeable battery can be used to construct an uninterruptible
power supply (UPS).
When designing a power supply, consider 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. System operating time for batteries can be determined by dividing the battery capacity (ampere
hours) by the average system current drain (amperes).
For more information see:
• Application Note - Power Supplies
• Power Budget Spreadsheet
• Video Tutorial - Power Budgeting
See also:
• "Power Input" on page 5
• "Power Output" on page 6
• "Power Requirements" on page 85
• "Power Output Specifications" on page 87
Updating the Operating System
Campbell Scientific posts operating system (OS) updates at www.campbellsci.com/downloads when
they become available. It is recommended that before deploying instruments, you check operating
system versions and update them as needed. The datalogger operating system version is shown in the
Status table, Station Status Summary, and Device Configuration Utility Deployment | Datalogger. An
operating system may be sent through Device Configuration Utility or through program-send
procedures.
Warning: Because sending an OS resets datalogger memory and resets all settings on the
datalogger to factory defaults, data loss will certainly occur. Depending on several factors, the
datalogger may also become incapacitated for a time. It is recommended that you retrieve data
from the datalogger and back up your programs before updating your OS; otherwise, data may be
lost. To collect data using LoggerNet, connect to your datalogger and click the Collect Now button
( ). To backup your datalogger, connect to it in Device Configuration Utility, click the Backup
menu and select Backup Datalogger.
62
Maintaining Your Datalogger
SENDING AN OPERATING SYSTEM TO A LOCAL DATALOGGER
Send an OS using Device Configuration Utility. This method requires a direct connection between your
datalogger and computer.
1. Download the latest Operating System at www.campbellsci.com/downloads.
2. Locate the .exe download and double-click to run the file. This will extract the .obj OS file to the
C:\Campbellsci\Lib\OperatingSystems folder.
3. Supply power to the datalogger. If connecting via USB for the first time, you must first install USB
drivers by using Device Configuration Utility (select your datalogger, then on the main page, click
Install USB Driver). Alternately, you can install the USB drivers using EZ Setup. A USB
connection supplies 5 V power (as well as a communication link), which is adequate for setup, but
a 12 V battery will be needed for field deployment.
4. Physically connect your datalogger to your computer using a USB cable, then open Device
Configuration Utility and select your datalogger.
5. Select the communication port used to communicate with the datalogger from the COM Port list
(you do not need to click Connect).
6. Click the Send OS tab. At the bottom of the window, click Start.
7. On the Avoid Conflicts with the Local Server window, click OK.
8. Navigate to the C:\Campbellsci\Lib\OperatingSystems folder.
9. Ensure Datalogger Operating System Files (*.obj) is selected in the Files of type list, select the
new OS .obj file, and click Open to update the OS on the datalogger.
Watch a video: Sending an OS to a Local Datalogger.
SENDING AN OPERATING SYSTEM TO A REMOTE DATALOGGER
If you have a datalogger that is already deployed, you can update the OS over a telecommunications
link by sending the OS to the datalogger as a program. In most instances, sending an OS as a program
preserves settings. This allows for sending supported operating systems remotely (check the release
notes). However, this should be done with great caution as updating the OS may reset the datalogger
settings, even settings critical to supporting the telecommunication link.
1. Download the latest Operating System at www.campbellsci.com/downloads.
2. Locate the .exe download and double-click to run the file. This will extract the .obj OS file to the
C:\Campbellsci\Lib\OperatingSystems folder.
3. Using datalogger support software, connect to your datalogger.
• LoggerNet users, select Main and click the Connect button (
) on the LoggerNet toolbar,
select the datalogger from the Stations list, then click the Connect button (
).
• PC200W and PC400 users, select the datalogger from the list and click the Connect button
(
).
4. Click File Control (
5. Click Send (
) at the top of the Connect window.
) at the top of the File Control window.
6. Navigate to the C:\Campbellsci\Lib\OperatingSystems folder.
Maintaining Your Datalogger
63
7. Ensure Datalogger Operating System Files (*.obj) is selected in the files of type list, select the
new OS .obj file, and click Open to update the OS on the datalogger.
Note the following precautions when sending as a program:
• Any peripherals being powered through the SW12 terminals will be turned off until the program
logic turns them on again.
• Operating systems are very large files. Be cautious of data charges. Sending over a direct serial
or USB connection is recommended, when possible.
64
Maintaining Your Datalogger
Tips and Troubleshooting
The following basic procedure can be used if a system is not operating properly.
1. Using a voltmeter, check the voltage of the primary power source at the POWER IN terminals on
the face of the datalogger.
2. Check wires and cables for the following:
• Incorrect wiring connections. Make sure each sensor and device are wired to the channels
assigned in the program. If the program was written in Short Cut, check wiring against the
generated wiring diagram. If written in CRBasic Editor, check wiring against each
measurement and control instruction.
• 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 impede 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 strippeddown 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.
4. Reset the datalogger. Sometimes the easiest way to resolve a problem is by resetting the
datalogger (see "Resetting the Datalogger" on page 70 for more information).
For additional troubleshooting options, see:
Checking Station Status....................................................................................................................... 65
Understanding NAN and INF Occurrences........................................................................................... 67
Time Keeping ...................................................................................................................................... 68
CRBasic Program Errors ..................................................................................................................... 69
Resetting the Datalogger ..................................................................................................................... 70
Troubleshooting Power Supplies ......................................................................................................... 71
Minimizing Ground Loop Errors ........................................................................................................... 71
Improving Voltage Measurement Quality ............................................................................................. 73
You can also find a number of troubleshooting articles at: www.campbellsci.com/blog/troubleshootingtopics.
Checking Station Status
View the condition of the datalogger using Station Status. Here you can see the operating system
version of the datalogger, the name of the current program, program compile results, and other key
indicators. Items that may need your attention appear in red or blue. The following information describes
Tips and Troubleshooting
65
the significance of some entries in the station status window. Watch a video or use the following
instructions.
VIEWING STATION STATUS
Using your datalogger support software, access the Station Status to view the condition of the
datalogger.
• From LoggerNet: Click Connect (
tab.
), then click the Station Status button to view the Summary
• From PC200W and PC400: Click the Datalogger menu and select Station Status to view the
Summary tab.
WATCHDOG ERRORS
Watchdog errors indicate that the datalogger has crashed and reset itself. Experiencing a few watchdog
errors is normal. You can reset the Watchdog error counter (noting the date you did so) in the Station
Status|Status Table. Watchdog errors could be due to:
• Transient voltage.
• Miswired or malfunctioning sensor.
• Poor ground connection on the power supply.
• Running the CRBasic program very fast.
• Numerous PortSet() instructions back-to-back with no delay.
• High-speed serial data on multiple ports with very large data packets or bursts of data.
The error "Results for Last Program Compiled: Warning: Watchdog Timer IpTask Triggered" can result
from:
• The IP communication on the datalogger got stuck, and the datalogger had to reboot itself to
recover. Or communications failures may cause the datalogger to reopen the IP connections
more than usual. Check your datalogger operating system version; recent operating system
versions have improved stability of IP communications.
If any of these are not the apparent cause, contact Campbell Scientific for assistance (see
https://www.campbellsci.com/support). Causes that may require assistance include:
• Memory corruption
• Operating System problem
• Hardware problem
• IP communications problem
RESULTS FOR LAST PROGRAM COMPILED
Messages generated by the datalogger at program upload and as the program runs are reported here.
Warnings indicate that an expected feature may not work, but the program will still operate. Errors
indicate that the program cannot run. For more information, see "CRBasic Program Errors" on page 69.
66
Tips and Troubleshooting
SKIPPED SCANS
Skipped scans are caused when a program takes longer to process than the scan rate allows. If any
scan skips repeatedly, the datalogger program may need to be optimized or reduced. For more
information, see: How to Prevent Skipped Scans and a Sunburn.
SKIPPED RECORDS
Skipped records usually occur because a scan is skipped. They indicate that a record was not stored to
the data table when it should have been.
VARIABLE OUT OF BOUNDS
Variable-out-of-bounds errors happen when an array is not sized to the demands of the program. The
datalogger attempts to catch all out-of-bounds errors at compile time and document the error. However,
it is not always possible, so these errors may occur during runtime.
BATTERY VOLTAGE
If powering through USB, reported battery voltage should be 0 V. If connecting to an external power
source, battery voltage should be reported at or near 12 V. See also:
• "Power Input" on page 5
• "Power Requirements" on page 85
Understanding NAN and INF Occurrences
NAN (not a number) and INF (infinite) are data words indicating an exceptional occurrence in
datalogger function or processing. INF indicates that the program has encountered an arithmetic
expression that is undefined. NAN indicates an invalid measurement. For more information, see Tips
and Tricks: Who's NAN?
NANs are expected in the following conditions:
• Input signals exceed the voltage range chosen for the measurement.
• An invalid SDI-12 command is sent
• An SDI-12 sensor does not respond or aborts without sending data
• Undefined arithmetic expressions, such as 0 ÷ 0.
NAN is a constant that can be used in expressions. This is 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
If a NAN is included in the values being processed, NAN will be stored. Note that since there is no such
thing as NAN for integers, values that are converted from float to integer will be expressed in data
tables as the most negative number for a given data type. For example, the most negative number of
data type FP2 is –7999, so NAN for FP2 data will appear in a data table as –7999. If the data type is
Long, NAN will appear in the data table as –2,147,483,648.
Tips and Troubleshooting
67
Because NAN is a constant, it can be used in conjunction with the disable variable parameter
(DisableVar) in output processing instructions. Use the DisableVar parameter to call the output
table conditionally (for example, do not call the table if a variable = NAN) to keep NANs from affecting
the other good values.
Time Keeping
Measurement of time is an essential function of the datalogger. Time measurement with the onboard
clock enables the datalogger to attach time stamps to data, measure the interval between events, and
time the initiation of control functions. Details on clock accuracy and resolution are available in the
"System Specifications" on page 85. An internal lithium battery backs the clock when the datalogger is
not externally powered (see "Internal Battery" on page 59 for more information).
CLOCK BEST PRACTICES
If you are going to set the clock with LoggerNet, initiate it manually during a maintenance period when
you are already disrupting site data.
If you are going to use automated clock check with LoggerNet, it is recommended that you do this on
the order of days (not hours). Set an allowed clock deviation that is appropriate for the expected jitter in
the network, and use the initial time setting to offset the clock check away from storage and
measurement intervals.
Take into account the amount of time that is required for the ClockCheck command to reach the
datalogger, be processed, and for it to send its response (round-trip time, or time-of-flight). LoggerNet
maintains a history of the round trip times for up to the ten previous successful clock check transactions
in order to calculate an estimate of this time of flight. It adds this average to the time values received
from the datalogger and subtracts it from any adjustment that it might make.
The ClockChange instruction can be used to:
• Detect, track, and log externally triggered clock change events.
• Characterize the jitter in your clock-syncing method.
TIME STAMPS
A measurement without an accurate time reference has little meaning. Data on the datalogger 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 datalogger. 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 timestamp skew of 510 ms.
AVOIDING TIME SKEW
Time skew between consecutive measurements is a function of settling and integration times, ADC, and
the number entered into the Reps parameter of CRBasic instructions.
68
Tips and Troubleshooting
Time-stamp skew is not a problem with most applications because:
• 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.
• 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:
• Making measurements in the scan before time-consuming code.
• Programming the datalogger such that the time stamp reflects the system time rather than the
scan time using the DataTime() instruction. See topics concerning data table declarations in
CRBasic Editor help for more information.
CRBasic Program Errors
Analyze data soon after deployment to ensure the datalogger is measuring and storing data as
intended. Most measurement and data-storage problems are a result of one or more CRBasic program
bugs. Watch a video: CRBasic | Common Errors - Identifying and fixing common errors in the CRBasic
programming language.
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 datalogger. This is rare, but reasons may include:
• The datalogger has a different operating system that is not fully compatible with the computer
compiler. Check the two versions if in doubt. The computer compiler version is shown on the first
line of the compile results. Update the computer compiler by first downloading the executable OS
file from www.campbellsci.com. When run, the executable file updates the computer compiler. To
update the datalogger operating system, see "Updating the Operating System" on page 62.
• The program has large memory requirements for data tables or variables and the datalogger
does not have adequate memory. This normally is flagged at compile time in the compile results.
If this type of error occurs, check:
o Copies of old programs on the CPU drive. The datalogger keeps copies of all program files
unless they are deleted, the drive is formatted, or a new operating system is loaded with
Device Configuration Utility.
o The USR drive size, is it too large? The USR drive may be using memory needed for the
program.
o Ensure the memory card is available when a program is attempting to access the CRD
drive.
PROGRAM COMPILES BUT DOES NOT RUN CORRECTLY
If the program compiles but does not run correctly, timing discrepancies are often the cause. 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
Tips and Troubleshooting
69
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.
Resetting the Datalogger
A reset is referred to as a "memory reset." Be sure to back up the current datalogger configuration
before a reset in case you need to revert to the old settings. To back up the datalogger configuration,
connect to the datalogger using Device Configuration Utility, and click Backup | Back Up Datalogger. To
restore a configuration after the datalogger has been reset, connect and click Backup | Restore
Datalogger.
The following features are available for complete or selective reset of datalogger memory:
• Processor reset.
• Program send reset.
• Manual data table reset.
• Formatting memory drives.
• Full memory reset.
PROCESSOR RESET
To reset the processor, simply power cycle the datalogger. This resets its short-term memory, restarts
the current program, sets variables to their starting values, and clears communication buffers. This does
not clear data tables but may result in a skipped record. If the datalogger is remote, a power cycle can
be mimicked in the Terminal Emulator program (type REBOOT <Enter>) or by using the Restart
CRBasic instruction.
PROGRAM SEND RESET
Final-storage data are erased when user programs are uploaded, unless preserve / erase data options
are used and the program was not altered. Preserve / erase data options are presented when sending
programs using File Control Send command and CRBasic Editor Compile, Save and Send.
When a program compiles, all variables are initialized. A program is recompiled after a power failure or
a manual stop. For instances that require variables to be preserved through a program recompile, the
CR1000X has the PreserveVariables() instruction.
MANUAL DATA TABLE RESET
Data table memory is selectively reset from:
• Datalogger support software: Station Status Table Fill Times tab, Reset Tables.
• Device Configuration Utility: Data Monitor tab, Reset Table button.
FORMATTING DRIVES
CPU, USR, CRD (memory card required), and USB (module required) drives can be formatted
individually. Formatting a drive erases all files on that drive. If the currently running user program is on
the drive to be formatted, the program will cease running and any SRAM data associated with the
70
Tips and Troubleshooting
program are erased. Drive formatting is performed through the datalogger support software File Control
| Format command.
FULL MEMORY RESET
Full memory reset occurs when an operating system is sent to the datalogger using Device
Configuration Utility or when entering 98765 in the Status table field FullMemReset. A full memory reset
does the following:
• 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.
Full memory reset does not affect the CRD drive directly. Subsequent user program uploads, however,
can erase CRD. See "Updating the Operating System" on page 62 for more information.
Troubleshooting Power Supplies
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. Check connections and check polarity of
connections.
Base diagnostic: connect the datalogger to a new 12 V battery. (A small 12 V battery carrying a full
charge would be a good thing to carry in your troubleshooting tool kit.) Ensure correct polarity of the
connection. If the datalogger powers up and works, troubleshoot the datalogger power supply.
When diagnosing or adjusting power equipment supplied by Campbell Scientific, it is recommended you
consider:
• 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. For additional information, see "Power Budgeting" on page 62.
Minimizing Ground Loop Errors
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)
Tips and Troubleshooting
71
sensor, a ground loop arises because soil and water provide an alternate path for the excitation to
return to datalogger ground. This example is modeled in the following image:
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 datalogger earth ground.
RsRf/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 datalogger 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.
See also "Grounds" on page 7.
72
Tips and Troubleshooting
Improving Voltage Measurement Quality
The following topics discuss methods of generally improving voltage measurements:
Deciding Between Single-Ended or Differential Measurements ........................................................... 73
Minimizing Ground Potential Differences ............................................................................................. 74
Detecting Open Inputs ......................................................................................................................... 75
Minimizing Power-Related Artifacts...................................................................................................... 75
Filtering to Reduce Measurement Noise .............................................................................................. 76
Minimizing Settling Errors .................................................................................................................... 77
Factors Affecting Accuracy .................................................................................................................. 79
Minimizing Offset Voltages .................................................................................................................. 80
Read More: Consult the following technical papers at www.campbellsci.com/app-notes for in-depth
treatments of several topics addressing voltage measurement quality:
• Preventing and Attacking Measurement Noise Problems
• Benefits of Input Reversal and Excitation Reversal for Voltage Measurements
• Voltage Accuracy, Self-Calibration, and Ratiometric Measurements
DECIDING BETWEEN SINGLE-ENDED OR DIFFERENTIAL MEASUREMENTS
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 tradeoffs of accuracy and precision, noise cancellation, 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.
• Passive Noise Rejection
o No voltage reference offset
o Common-mode noise rejection, which filters capacitively coupled noise
• Active Noise Rejection
o Input reversal
o For more information, see "Compensating for Offset Voltage" on page 81.
Reasons for using single-ended measurements, however, include:
• Not enough differential terminals are available. Differential measurements use twice as many
analog input 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 drawbacks 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.
Tips and Troubleshooting
73
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.
Because a single-ended measurement is referenced to datalogger ground, any difference in ground
potential between the sensor and the datalogger will result in an error in the measurement. For more
information on grounds, see "Grounds" on page 7 and "Minimizing Ground Potential Differences" on
page 74.
MINIMIZING GROUND POTENTIAL DIFFERENCES
Low-level, single-ended voltage measurements (<200 mV) are sensitive to ground potential fluctuation
due to changing return currents from 5V,12V, SW12, and C terminals. The datalogger grounding
scheme is designed to minimize these fluctuations by separating signal grounds ( ) from power
grounds (G). For more information on datalogger grounds, see "Grounds" on page 7. To take
advantage of this design, observe the following rules:
• Connect grounds associated with 5V,12V, SW12, and C 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.
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.
Ground Potential Differences
Because a single-ended measurement is referenced to datalogger ground, any difference in ground
potential between the sensor and the datalogger 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
datalogger ground.
Ground potential differences are a common problem when measuring full-bridge sensors (strain gages,
pressure transducers, etc), and when measuring thermocouples in soil.
• 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 datalogger 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.
• 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 datalogger. These instruments are often powered by the same Vac-line source
as the datalogger. 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.
For additional information, see "Minimizing Offset Voltages" on page 80.
74
Tips and Troubleshooting
DETECTING OPEN INPUTS
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 detection. For detailed information, see the
CRBasic help (VoltSE() and VoltDiff() instructions, Range parameter)
The C option may not work, or may not work well, in the following applications:
• 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 to a normal voltage through external
leakage to ground 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 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 ADC may mitigate the problem.
MINIMIZING POWER-RELATED ARTIFACTS
Some Vac-to-Vdc power converters produce switching noise or ac ripple as an artifact of the ac-to-dc
rectification process. Excessive switching noise on the output side of a power supply can increase
measurement noise, and so increase measurement error. Noise from grid or mains power also may be
transmitted through the transformer, or induced electromagnetically from nearby motors, heaters, or
power lines.
High-quality power regulators typically reduce noise due to power regulation. Using the 50 Hz or 60 Hz
fN1 option for CRBasic analog input measurement instructions often improves rejection of noise
sourced from power mains. The CRBasic standard deviation instruction, StdDev(), can be used to
evaluate measurement noise.
The datalogger includes adjustable digital filtering, which serves two purposes:
• Arrive as close as possible to the true input signal
• Filter out measurement noise at specific frequencies, the most common being noise at 50 Hz or
60 Hz, which originate from mains-power lines.
Filtering time is inversely proportional to the frequency being filtered.
Minimizing 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. The following image illustrates the
common-mode 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 = (V+ + V–)/2 or the voltage remaining on
Tips and Troubleshooting
75
the inputs when Vdm = 0. The total voltage on the V+ and V– inputs is given as VH = Vcm + Vdm/2, and VL
= Vcm – Vdm/2, respectively.
FILTERING TO REDUCE MEASUREMENT NOISE
An adjustable filter is applied to analog measurements, reducing signal components at selected
frequencies. The following figure shows the filter’s frequency response. Using the first notch frequency
(fN1) parameter, users can select the placement of the filter’s notches. The first notch falls at the
specified fN1, and subsequent notches fall at integer multiples of fN1. Commonly, fN1 is set at 50 or
60 Hz in order to filter 50 or 60 Hz signal components, reducing noise from ac power mains.
Filtering comes at the expense of measurement time. The time required for filtering is equal to 1/fN1. For
example, setting fN1 equal to 50 will require 1/50 sec (20 ms) for filtering. As fN1 is set to smaller
values, random noise in the measurement results decreases, while measurement time increases. The
total time required for a single result includes settling + filtering + overhead.
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Tips and Troubleshooting
Consult the following technical paper at www.campbellsci.com/app-notes for in-depth treatment of
measurement noise: Preventing and Attacking Measurement Noise Problems.
CR1000X Filtering Details
The datalogger utilizes a sigma-delta ADC that outputs digitized data at a rate of 31250 samples per
second. User-specified filtering is achieved by averaging several samples from the ADC. Recall that
averaging the signal over a period of 1/fN1 seconds will filter signal components at fN1 Hz. The final
result, then, is the average calculated from 31250/fN1 samples. For example, if fN1 is set to 50 Hz, 625
samples (31250 / 50) are averaged to generate the final filtered result.
The actual fN1 may deviate from the user-specified setting since a whole integer number of samples
must be averaged. For example, if fN1 is set to 60 Hz, 521 samples (31250 / 60 = 520.83) will be
averaged to produce the filtered result. The rounding of 520.83 to 521 moves the actual fN1 to 31250 /
521 = 59.98 Hz.
MINIMIZING SETTLING ERRORS
Settling time allows an analog voltage signal to rise or fall closer to its true magnitude prior to
measurement. 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 cables. The time to
complete a measurement 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 to perform the instruction.
When sensors require long lead lengths, use the following general practices to minimize settling errors:
• 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.
• In difficult cases where measurement speed is a consideration, an appropriate settling time can
be determined through testing.
•
Measuring Settling Time
Settling time for a particular sensor and cable can be measured with the CR1000X. 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.
The following CRBasic Example: Measuring Settling Time 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.
Tips and Troubleshooting
77
CRBasic Example: Measuring Settling Time
'This program example demonstrates the measurement of settling time
'using a single measurement instruction multiple times in succession.
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,mV200,Vx1,1,2500,True,True,100,15000 ,1.0,0)
BrFull(PT(2),1,mV200,Vx1,1,2500,True,True,200,15000 ,1.0,0)
BrFull(PT(3),1,mV200,Vx1,1,2500,True,True,300,15000 ,1.0,0)
BrFull(PT(4),1,mV200,Vx1,1,2500,True,True,400,15000 ,1.0,0)
BrFull(PT(5),1,mV200,Vx1,1,2500,True,True,500,15000 ,1.0,0)
BrFull(PT(6),1,mV200,Vx1,1,2500,True,True,600,15000 ,1.0,0)
BrFull(PT(7),1,mV200,Vx1,1,2500,True,True,700,15000 ,1.0,0)
BrFull(PT(8),1,mV200,Vx1,1,2500,True,True,800,15000 ,1.0,0)
BrFull(PT(9),1,mV200,Vx1,1,2500,True,True,900,15000 ,1.0,0)
BrFull(PT(10),1,mV200,Vx1,1,2500,True,True,1000,15000 ,1.0,0)
BrFull(PT(11),1,mV200,Vx1,1,2500,True,True,1100,15000 ,1.0,0)
BrFull(PT(12),1,mV200,Vx1,1,2500,True,True,1200,15000 ,1.0,0)
BrFull(PT(13),1,mV200,Vx1,1,2500,True,True,1300,15000 ,1.0,0)
BrFull(PT(14),1,mV200,Vx1,1,2500,True,True,1400,15000 ,1.0,0)
BrFull(PT(15),1,mV200,Vx1,1,2500,True,True,1500,15000 ,1.0,0)
BrFull(PT(16),1,mV200,Vx1,1,2500,True,True,1600,15000 ,1.0,0)
BrFull(PT(17),1,mV200,Vx1,1,2500,True,True,1700,15000 ,1.0,0)
BrFull(PT(18),1,mV200,Vx1,1,2500,True,True,1800,15000 ,1.0,0)
BrFull(PT(19),1,mV200,Vx1,1,2500,True,True,1900,15000 ,1.0,0)
BrFull(PT(20),1,mV200,Vx1,1,2500,True,True,2000,15000 ,1.0,0)
CallTable Settle
NextScan
EndProg
The first six measurements are shown in the following table:
Timestamp
8/3/2017 23:34
8/3/2017 23:34
8/3/2017 23:34
8/3/2017 23:34
8/3/2017 23:34
Rec
PT(1)
Smp
PT(2)
Smp
PT(3)
Smp
PT(4)
Smp
PT(5)
Smp
PT(6)
Smp
0
1
2
3
4
0.03638599
0.03658813
0.03638599
0.03658813
0.03679027
0.03901386
0.03921601
0.03941815
0.03941815
0.03921601
0.04022673
0.04002459
0.04002459
0.03982244
0.04022673
0.04042887
0.04042887
0.04063102
0.04042887
0.04063102
0.04103531
0.04103531
0.04042887
0.04103531
0.04063102
0.04123745
0.0414396
0.04123745
0.04103531
0.04083316
Each trace in the following image 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
78
Tips and Troubleshooting
in variable PT(14). This is suitable accuracy for the application, so a settling time of 1400 µs is
determined to be adequate.
FACTORS AFFECTING ACCURACY
Accuracy describes the difference between a measurement and the true value. Many factors affect
accuracy. This topic discusses the effect percent-of-reading, 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 and offsets are displayed in the "Analog Measurements Specifications" on
page 88.
Note: Error discussed in this section and error-related specifications of the datalogger do not
include error introduced by the sensor or by the transmission of the sensor signal to the
datalogger.
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:
• Sensor-signal voltage: ≈1050 mV
• CRBasic measurement instruction: VoltDiff()
• Programmed input-voltage range (Range): mV5000 (±5000 mV)
Tips and Troubleshooting
79
• Input measurement reversal (RevDiff): True
• Datalogger circuitry temperature: 10° C
Accuracy of the measurement is calculated as follows:
accuracy = percent-of-reading + offset
where
percent-of-reading = 1050 mV • ±0.04%
= ±0.42 mV
and
offset = 0.5 µV
Therefore,
accuracy = ±(0.42 mV + 0.5 µV) = ±0.4205 mV
MINIMIZING OFFSET VOLTAGES
Voltage offset can be the source of significant error. For example, an offset of 3 μV on a 2500 mV signal
causes an error of only 0.00012%, but the same offset on a 0.25 mV signal causes an error of 1.2%.
Measurement offset voltages are unavoidable, but can be minimized. Offset voltages originate with:
• Ground currents (see "Minimizing Ground Potential Differences" on page 74 for more
information).
• Seebeck effect.
• Residual voltage from a previous measurement.
Remedies include:
• Connecting power grounds to power ground terminals (G).
• Using input reversal (RevDiff = True) with differential measurements.
• Automatic offset compensation for differential measurements when RevDiff = False.
• Automatic offset compensation for single-ended measurements when MeasOff = False.
• Using MeasOff = True for better offset compensation.
• Using excitation reversal (RevEx = True) with bridge measurments.
• Programming longer settling times.
Single-ended measurements are susceptible to voltage drop at the ground terminal caused by return
currents from another device that is powered from the datalogger wiring panel, such as another
manufacturer's communication 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, 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 datalogger moves to the next measurement. However, if the CRBasic program is written
80
Tips and Troubleshooting
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 cancellation occurring between matched high
and low pairs such as 1H/1L. So, use differential measurements when measuring critical low-level
voltages, especially those below 200 mV, such as are output from pyranometers and thermocouples.
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:
• Programing longer settling times.
• Using an individual instruction for each input terminal, the effect of which is to reset the integrator
circuit prior to filtering.
• Avoiding preceding a very small voltage input with a very large voltage input in a measurement
sequence if a single measurement instruction must be used.
The following Offset Voltage Compensation Options table lists some of the tools available to minimize
the effects of offset voltages:
CRBasic
Measurement
Instruction
BrHalf()
BrHalf3W()
BrHalf4W()
BrFull()
BrFull6W()
TCDiff()
TCSe()
VoltDiff()
VoltSe()
Input
Excitation Reversal
Measure Offset
Reversal
(RevEx=True)
During Measurement
(RevDiff=
(MeasOff=True)
True)
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
✔
Measure Offset During
Background Calibration
(RevDiff=False)
(RevEx=False)
(MeasOff=False)
✔
✔
✔
✔
✔
✔
✔
✔
✔
Compensating for Offset Voltage
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.
Ratiometric measurements use an excitation voltage 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.
Tips and Troubleshooting
81
For example, if 3 µV 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
Ratiometric differential measurement instructions allow both RevDiff and RevEx to be set True. This
results in four measurement sequences, which the datalogger processes into the reported
measurement:
• positive excitation polarity with positive differential input polarity
• negative excitation polarity with positive differential input polarity
• positive excitation polarity with negative differential input polarity
• negative excitation polarity with negative 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 determined from self-calibration.
When the datalogger 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 submeasurements 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.
Switch to the measurement terminals.
2.
Set the excitation, settle, and then measure.
3.
Reverse the excitation, settle, and then measure.
4.
Reverse the excitation, reverse the input terminals, settle, measure.
5.
Reverse the excitation, settle, measure.
There are four delays per 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: The Benefits of Input Reversal and Excitation Reversal for Voltage Measurements.
Measuring Ground Reference Offset Voltage
Single-ended and differential measurements without input reversal use an offset voltage measurement
with the PGIA inputs grounded. This offset voltage is subtracted from the subsequent measurement.
For differential measurements without input reversal, this offset voltage measurement is performed as
part of the routine background calibration of the datalogger (see "About Background Calibration" on
page 55 for more information). Single-ended measurement instructions VoltSE() and TCSe() include
the MeasOff parameter determines whether the offset voltage measured is done at the beginning of
the 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() or TCSe()
instruction. When MeasOff = False, measurements will be corrected for the offset voltage
determined during self-calibration. For installations experiencing fluctuating offset voltages, choosing
82
Tips and Troubleshooting
MeasOff = True for the VoltSE() or TCSe() instruction results in better offset voltage
performance.
If RevDiff, RevEx, or MeasOff is disabled (= False), offset voltage compensation is automatically
performed, albeit less effectively, by using measurements from the 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:
• RevDiff, RevEx, and MeasOff are more effective.
• 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 datalogger temperatures and
return currents are slow to change.
Field Calibration
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 the FieldCal() or FieldCalStrain() instruction to a
CRBasic program, measurements of a linear sensor can be adjusted by modifying the programmed
multiplier and offset applied to the measurement, without modifying or recompiling the CRBasic
program. For more information, see the CRBasic help.
File System Error Codes
Errors can occur when attempting to access files on any of the available drives. All occurrences are
rare, but they are most likely to occur when using optional memory cards. Often, formatting the drive will
resolve the error. The errors display in the File Control messages box or in the Status table.
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
Tips and Troubleshooting
83
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
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
File Name and Resource Errors
The maximum size of the file name that can be stored, run as a program, or FTP transferred in the
datalogger is 59 characters. If the name + file extension is longer than 59 characters, an Invalid
Filename error is displayed. If several files are stored, each with a long file name, 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.
Background Calibration Errors
Background calibration errors are rare. When they do occur, the cause is usually an analog input that
exceeds the input limits of the datalogger.
• 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.
• Check for condensation, which can sometimes cause leakage from a 12 Vdc source terminal.
• 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.
84
Tips and Troubleshooting
Specifications
Electrical specifications are valid over a -40 to +70 °C, non-condensing environment, unless otherwise
specified. Extended electrical specifications (noted as XT in specifications) are valid over a -55 to +85
°C non-condensing environment. Recalibration is recommended every three years. Critical
specifications and system configuration should be confirmed with Campbell Scientific before purchase.
System Specifications .......................................................................................................................... 85
Physical Specifications ........................................................................................................................ 85
Power Requirements ........................................................................................................................... 85
Ground Specifications .......................................................................................................................... 86
Power Output Specifications ................................................................................................................ 87
Analog Measurements Specifications .................................................................................................. 88
Current-Loop Measurements Specifications ........................................................................................ 90
Pulse Measurements Specifications .................................................................................................... 91
Digital Input/Output Specifications ....................................................................................................... 91
Communications Specifications ........................................................................................................... 92
System Specifications
Processor: Renesas RX63N (32-bit with hardware FPU, running at 100 MHz)
Memory (see "Memory and Data Storage" on page 26 for more information):
• 128 MB of flash + 4 MB battery-backed SRAM
• Data Storage: 4 MB SRAM + 72 MB flash
• Data Storage Expansion: Removable microSD flash memory, up to 8 GB
Program Execution: 1 ms to 1 day
Real-Time Clock:
• Battery backed while external power is disconnected
• Resolution: 1 ms
• Accuracy: ±3 min. per year, optional correction (±10 µs) using GPS, PakBus, or NTP
Wiring Panel Temperature: A thermistor, located between the two rows of analog input channels, is
measured when reporting wiring panel temperature.
Physical Specifications
Dimensions: 20.3 x 10.1 x 5.6 cm (8.0 x 4.0 x 2.2 in); additional clearance required for cables and leads.
Weight/Mass: 0.42 kg (.92 lb)
Power Requirements
Protection: Power inputs are protected against surge, over-voltage, over-current, and reverse power.
Specifications
85
Power In Terminal:
• Voltage Input: 10 to 18 Vdc
• Input Current Limit at 12 Vdc:
o 4.35 A at -40°C
o 3 A at 20 °C
o 1.56 A at 85 °C
• 30 Vdc sustained voltage limit without damage. Transient voltage suppressor (TVS) diodes at the
POWER IN terminal clamps transients to 36 to 40 V. Input voltages greater than 18 V and less
than 32 V are tolerated; however, the 12 V output SW12-1 and SW12-2 are disabled and will not
function until the input voltage falls below 16 V. Sustained input voltages in excess of 32 V can
damage the TVS diodes. If the voltage on the POWER IN terminals exceeds 19 V, power is shut
off to certain parts of the datalogger to prevent damaging connected sensors or peripherals.
USB Power: Functions that will be active with USB 5 Vdc include sending programs, adjusting
datalogger settings, and making some measurements. If USB is the only power source, then the CS I/O
port and the 5V, 12V, and SW12 terminals will not be operational. When powered by USB (no other
power supplies connected) Status field Battery = 0.
Internal Lithium Battery: AA, 2.4 Ah, 3.6 Vdc (Tadiran TL 5903/S) for battery-backed SRAM and clock.
3-year life with no external power source. See also "Internal Battery" on page 59.
Average Current Drain (assumes 12 Vdc on POWER IN terminals):
• Idle: <1 mA
• Active 1 Hz Scan: 1 mA
• Active 20 Hz Scan: 55 mA
• Serial (RS-232/RS-485): Active + 25 mA
• Ethernet Power Requirements:
o Ethernet 1 Minute: Active + 1 mA
o Ethernet Idle: Active + 4 mA
o Ethernet Link: Active + 48 mA
Vehicle Power Connection: When primary power is pulled from the vehicle power system, a second
power supply OR charge regulator may be required to overcome the voltage drop at vehicle startup.
Ground Specifications
Signal Ground ( ) - reference for single-ended analog inputs, excitation returns, and a ground for
sensor shield wires.
• 11 common terminals
Power Ground (G) - return for 5V, 12V and digital sensors.
• 4 common terminals
Earth Ground Lug (
is recommended.
86
Specifications
) - connection point for heavy-gauge earth-ground wire. 14 AWG wire, minimum,
Resistive Ground (RG) - two resistance-to-ground inputs that can be used for non-isolated 0-20 mA and
4-20 mA current loop measurements or for terminating the ground reference of an RS-485 serial
connection. Maximum voltage for RG terminals is ±16 V. See also "Current-Loop Measurements
Specifications" on page 90.
Power Output Specifications
System Power Out Limits (when powered with 12 Vdc):
Temperature (°C)
Current Limit1 (A)
–40°
20°
70°
85°
4.53
3.00
1.83
1.56
1Limited
by self-resetting thermal fuse
5V, 12V, and SW12V Power Output Terminals:
• 12V, SW12-1, and SW12-2: Provide unregulated 12 Vdc power with voltage equal to the Power
Input supply voltage. These are disabled when operating on USB power only. The 12V terminal is
limited to the current shown in the previous table.
SW12-1 and SW12-2 can be independently set under program control. Each SW12 terminal has
a hold current limited to the values in the following table. See the VX terminal information for
additional regulated voltage outputs.
Temperature (°C)
Current Limit 1 (mA)
–40°
0°
20°
50°
70°
80°
1310
1040
900
690
550
470
1Thermal
fuse hold current. Overload causes voltage drop. Disconnect and let cool to reset. Operate at limit if the
application can tolerate some fluctuation.
• 5V: One regulated 5V output. Supply is shared between the 5V terminal and CS I/O DB9 5 V
output. (See the VX terminal information for additional regulated voltage outputs.)
o Voltage Output: Regulated 5 V output (±5%)
o Current Limit: 230 mA
C as Power Output:
Values reflect a thermal fuse limit current. Circuit holds current at the maximum by dropping the voltage
when the load is too great. To reset, disconnect and allow circuit to cool. Operating at the current limit is
OK so long some fluctuation can be tolerated. Drive capacity is determined by the logic level of the Vdc
supply and the output resistance (Ro) of the terminal.
o Output Resistance (Ro): 150 Ω
o 5 V Logic Level Drive Capacity: 10 mA @ 3.5 Vdc; Vout = 5 V - (Iout × 150 Ω)
o 3.3 V Logic Level Drive Capacity: 10 mA @ 1.8 Vdc; Vout = 3.3 V - (Iout × 150 Ω)
Specifications
87
• VX: Four independently configurable voltage terminals (VX1-VX4). When providing voltage
excitation, a single 16-bit DAC shared by all VX outputs produces a user-specified voltage during
measurement only. In this case, these terminals are regularly used with resistive-bridge
measurements (see "Resistance Measurements" on page 35 for more information).VX terminals
can also be used to supply a selectable, switched, regulated 3.3 or 5 Vdc power source to power
digital sensors and toggle control lines.
Range
Voltage Excitation
±4 V
Switched, Regulated +3.3 or 5 V
Resolution
Accuracy12
Maximum Source/Sink
Current3
0.06 mV ±(0.1% of setting + 2 mV)
3.3 or 5 V
±5%
±40 mA
50 mA
Valid over -55 to +85 °C temperature range
Note that ratiometric accuracy, rather than the absolute accuracy of excitation or analog measurement, determines
the accuracy of ratiometric resistance measurements.
3 Exceeding current limits causes voltage output to become unstable. Voltage should stabilize when current is reduced
to within stated limits.
1
2
Analog Measurements Specifications
16 single-ended (SE) or 8 differential (DIFF) inputs individually configurable for voltage, thermocouple,
ratiometric, and period average measurements, using a 24-bit ADC. One channel at a time is measured
in numeric succession.
VOLTAGE MEASUREMENTS
Terminals:
• Differential Configuration: DIFF 1H/1L – 8H/8L
• Single-Ended Configuration: SE1 – SE16
Input Resistance: 20 GΩ
Input Limits: ±5 V
Sustained Input Voltage without Damage: ±20 Vdc
Dc Common Mode Rejection:
• > 120 dB with input reversal
• ≥ 86 dB without input reversal
Normal Mode Rejection: > 70 dB @ 60 Hz
Input Current @ 25 °C: ±1 nA typical
Filter First Notch Frequency (fN1) Range: 0.5 Hz to 31.25 kHz (user specified)
88
Specifications
Analog Range and Resolution:
Differential with Input
Reversal
Notch Frequency (fN1)1 (Hz) Range2
(mV)
RMS (µV)
Bits3
8.2
1.9
0.75
0.6
0.14
0.05
0.18
0.04
0.02
20
20
19
24
23
22
25
25
24
±5000
±1000
±200
±5000
±1000
±200
±5000
±1000
±200
15000
50/604
5
Single-Ended and
Differential
without Input Reversal
RMS (µV)
Bits3
11.8
2.6
1.0
0.88
0.2
0.08
0.28
0.07
0.03
19
19
18
23
23
22
25
24
23
Valid frequencies are 0.5 Hz to 31.25 kHz.
Range overhead of ~5% on all ranges guarantees that full-scale values will not cause over range.
3 Typical effective resolution (ER) in bits; computed from ratio of full-scale range to RMS resolution.
4 50/60 corresponds to rejection of 50 and 60 Hz ac power mains noise.
1
2
Accuracy (does not include sensor or measurement noise):
• 0 to 40 °C: ±(0.04% of measurement + offset)
• –40 to 70 °C: ±(0.06% of measurement + offset)
• –55 to 85 °C (XT): ±(0.08% of measurement + offset)
Voltage Measurement Accuracy Offsets:
Range (mV)
±5000
±1000
±200
Typical Offset (µV RMS)
Differential
Single-Ended or Differential
with Input Reversal
without Input Reversal
±0.5
±0.25
±0.15
±2
±12
±0.5
Multiplexed Measurement Time: (450 µs + settling time + (1/fN1)) • reps
(Default settling time of 500 µs. These are not maximum speeds. Multiplexed denotes circuitry inside
the datalogger that switches signals into the ADC.)
Multiplexed Measurement Time (ms) with 500 µs Settling Time:
Example fN11 (Hz)
15000
60
50
5
1Notch
Differential
Single-Ended or Differential
with Input Reversal
without Input Reversal
Time (ms)
Time (ms)
2.04
35.24
41.9
401.9
1.02
17.62
20.95
200.95
frequency (1/integration time).
Measurement Settling Time: 20 µs to 600 ms; 500 µs default
Specifications
89
RESISTANCE MEASUREMENTS SPECIFICATIONS
The datalogger makes ratiometric-resistance measurements for four- and six-wire full bridge circuits
and two-, three-, and four-wire half bridge circuits using voltage excitation. Excitation polarity reversal is
available to minimize dc error. Typically, at least one terminal is configured for excitation output.
Multiple sensors may be able to use a common excitation terminal.
Accuracy: Assumes input reversal for differential measurements along with excitation reversal for
excitation voltage <1000 mV. Does not include bridge resistor errors or sensor and measurement noise.
Ratiometric accuracy, rather than absolute accuracy, determines overall measurement accuracy. Offset
is the same as specified for analog voltage measurements.
• 0 to 40 °C: ±(0.01% of voltage measurement + offset)
• –40 to 70 °C: ±(0.015% of voltage measurement + offset)
• –55 to 85 °C (XT): ±(0.02% of voltage measurement + offset)
PERIOD-AVERAGING MEASUREMENTS SPECIFICATIONS
Up to 16 analog inputs may be configured for period averaging.
Accuracy: ±(0.01% of measurement + resolution), where resolution is 0.13 µs divided by the number of
cycles to be measured
Ranges:
• Minimum signal centered around specified period average threshold.
• Maximum signal centered around datalogger ground.
• Maximum frequency = 1/(2 * (minimum pulse width)) for 50% duty cycle signals
Gain Code
Minimum
Maximum
Minimum
Maximum
Option
Peak to Peak Signal (mV) Peak to Peak Signal (V) Pulse Width (µs) Frequency (kHz)
0
1
2
3
500
50
10
2
10
2
2
2
2.5
10
62
100
200
50
8
5
Current-Loop Measurements Specifications
The datalogger makes current-loop measurements by measuring across a current-sense resistor
associated with the RS-485 resistive ground terminals RG1 & RG2.
Maximum Input Voltage: ±16 V
Resistance to Ground: 101 Ω
Current Measurement Shunt Resistance: 10 Ω
Maximum Current Measurement Range: ±80 mA
Absolute Maximum Current: ±160 mA
Current Measurement Resolution: ≤ 20 nA
Current Measurement Accuracy: ±(0.1% of Reading + 100 nA) @ -40 to 70 °C
See also "Current-Loop Measurements" on page 33.
90
Specifications
Pulse Measurements Specifications
Two inputs (P1-P2) individually configurable for switch closure, high-frequency pulse, or low-level AC
measurements. See also "Digital Input/Output Specifications" on page 91. Each terminal has its own
independent 32-bit counter.
Maximum Input Voltage: ±20 Vdc
Maximum Counts Per Channel: 232
Maximum Counts Per Scan: 232
Input Resistance: 5 kΩ
Accuracy: ±(0.02% of reading + 1/scan)
SWITCH CLOSURE INPUT
Pull-Up Resistance: 100 kΩ to 5 V
Event: Low (<0.8 V) to High (>2.5 V)
Maximum Input Frequency: 150 Hz
Minimum Switch Closed Time: 5 ms
Minimum Switch Open Time: 6 ms
Maximum Bounce Time: 1 ms open without being counted
HIGH-FREQUENCY INPUT
Pull-Up Resistance: 100 kΩ to 5 V
Event: Low (<0.8 V) to High (>2.5 V)
Maximum Input Frequency: 250 kHz
LOW-LEVEL AC INPUT
Minimum Pull-Down Resistance: 10 kΩ to ground
Dc-offset Rejection: Internal ac coupling eliminates dc-offset voltages up to ±0.5 Vdc
Input Hysteresis: 12 mV @ 1 Hz
Low-Level Ac Pulse Input Ranges:
• Sine Wave Input 20 mv RMS, Input Frequency Range 1.0 to 20 Hz
• Sine Wave Input 200 mv RMS, Input Frequency Range 0.5 to 200 Hz
• Sine Wave Input 2000 mv RMS, Input Frequency Range 0.3 to 10,000 Hz
• Sine Wave Input 5000 mv RMS, Input Frequency Range 0.3 to 20,000 Hz
Digital Input/Output Specifications
8 terminals (C1-C8) configurable for digital input and output (I/O) including status high/low, pulse width
modulation, external interrupt, edge timing, switch closure pulse counting, high-frequency pulse
counting, UART, RS-232, RS-485, SDM, SDI-12, I2C, and SPI function. Terminals are configurable in
pairs for 5 V or 3.3 V logic for some functions. Conflicts can occur when companion ports are used for
Specifications
91
different instructions (TimerInput, PulseCount, SDI12Recorder, WaitDigTrig). For example, if
C3 is used for the SDI12Recorder instruction, C4 cannot be used in the TimerInput, PulseCount,
or WaitDigTrig instructions.
Maximum Input Voltage: ±20 V
Logic Levels and Drive Current:
Drive Current Logic Low Logic High Current Source
5V
3.3 V
≤ 1.5 V
≤ 0.8 V
≥ 3.5 V
≥ 2.5 V
10 mA @ 3.5 V
10 mA @ 1.85 V
SWITCH CLOSURE INPUT
Accuracy: ±(0.02% of reading + 1/scan)
Resistance: Configurable in terminal pairs with 100 kΩ pull-up or pull-down
Software Debounce Time: 3 ms
Maximum Bounce Time: 1 ms open without being counted
Maximum Input Frequency: 150 Hz
HIGH-FREQUENCY INPUT
Accuracy: ±(0.02% of reading + 1/scan)
Resistance: Configurable in terminal pairs with 100 kΩ pull-up or pull-down
Maximum Input Frequency: 1 MHz
EDGE TIMING
Maximum Input Frequency: ≤ 2.3 Hz
Resolution: 500 ns
PULSE-WIDTH MODULATION
Terminals: C1-C8
Period Maximum: 36.4 seconds
Resolution
• 0 – 5 ms: 83.33 ns
• 5 – 325 ms: 5.33 µs
• > 325 ms: 31.25 µs
Communications Specifications
A datalogger is normally part of a two-way conversation started by a computer. In applications with
some types of interfaces, the datalogger can also initiate the call (callback) when needed. In satellite
applications, the datalogger may simply send bursts of data at programmed times without waiting for a
response.
Ethernet Port: RJ45/ jack, 10/100Base Mbps, full and half duplex, Auto-MDIX, magnetic isolation, and
TVS surge protection. See also "Ethernet Communications" on page 14.
92
Specifications
Internet Protocols: Ethernet, PPP, CS I/O IP, RNDIS, ICMP/Ping, Auto-IP(APIPA), IPv4, IPv6, UDP,
TCP, TLS, DNS, DHCP, SLAAC, SNMPv3, NTP, Telnet, HTTP(S), FTP(S), SMTP/TLS, POP3/TLS
Additional Protocols: PakBus, PakBus Encryption, CPI, SDM, SDI-12, Modbus RTU / ASCII / TCP,
DNP3, NTCIP, NMEA 0183, I2C, SPI, custom user definable over serial, UDP
Data File Formats: CSV, XML, JSON, binary, encrypted, custom user definable
USB: Micro-B device for computer connectivity
CS I/O: 9-pin D-sub multidrop interface to interface with Campbell Scientific CS I/O peripherals
CS I/O Pinout:
Pin
Function Input (I)
Number
Output(O)
1
5 Vdc
O
2
SG
3
4
RING
RXD
I
I
5
ME
O
6
SDE
O
7
CLK/HS
I/O
8
12 Vdc
9
TXD
O
Description
5 Vdc: sources 5 Vdc, used to power peripherals.
Signal ground: provides a power return for pin 1 (5V), and is used as a
reference for voltage levels.
Ring: raised by a peripheral to put the CR1000X in the telecom mode.
Receive data: serial data transmitted by a peripheral are received on pin 4.
Modem enable: raised when the CR1000X determines that a modem raised
the ring line.
Synchronous device enable: addresses synchronous devices (SD); used as an
enable line for printers.
Clock/handshake: with the SDE and TXD lines addresses and transfers data to
SDs. When not used as a clock, pin 7 can be used as a handshake line; during
printer output, high enables, low disables.
Nominal 12 Vdc power. Same power as 12V and SW12 terminals.
Transmit data: transmits serial data from the datalogger to peripherals on pin
9; logic-low marking (0V), logic-high spacing (5V), standard-asynchronous
ASCII: eight data bits, no parity, one start bit, one stop bit. User selectable
baud rates: 300, 1200, 2400, 4800, 9600, 19200, 38400, 115200.
RS-232/CPI: Single RJ45 module port that can operate in one of two modes: RS-232 or CPI. RS-232
connects to computer, sensor, or communication devices serially. CPI interfaces with Campbell
Scientific CDM measurement peripherals and sensors.
RS-232/CPI Pinout:
Pin Number
1
2
3
4
5
6
7
8
9
Description
RS-232: Transmit (Tx)
RS-232: Receive (Rx)
100 Ω Res Ground
CPI: Data
CPI: Data
100 Ω Res Ground
RS-232 CTS CPI: Sync
RS-232 DTR CPI: Sync
Not Used
Specifications
93
Glossary
A
ac
Alternating current (see Vac).
accuracy
The degree to which the result of a measurement, calculation, or specification conforms to the correct value or a
standard.
ADC
Analog to digital conversion. The process that translates analog voltage levels to digital values.
amperes (A)
Base unit for electric current. Used to quantify the capacity of a power source or the requirements of a powerconsuming device.
analog
Data presented as continuously variable electrical signals.
argument
Part of a procedure call (or command execution).
ASCII/ANSI
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 pre-defined
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.
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. Also indicates
the sending and receiving devices are not synchronized using a clock signal.
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.
B
baud rate
The rate at which data are transmitted.
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.
binary
Describes data represented by a series of zeros and ones. Also describes the state of a switch, either being on
or off.
94
Glossary
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.
boolean
Name given a function, the result of which is either true or false.
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.
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.
C
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.
callback
A name given to the process by which the datalogger initiates communications with a computer running
appropriate Campbell Scientific datalogger support software. Also known as "Initiate Comms."
CardConvert software
A utility to retrieve binary final-storage data from memory cards and convert the data to ASCII or other formats.
CD100
An optional enclosure mounted keyboard/display for use with dataloggers.
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 datathroughput rates and use of longer cables. CDM devices require more power to operate in general than do SDM
devices.
CF
CompactFlash®
code
A CRBasic program, or a portion of a program.
Collect button
Button or command in datalogger support software that facilitates collection-on-demand of final-data memory.
This feature is found in PC200W, PC400, LoggerNet, and RTDAQ software.
Collect Now button
Button or command in datalogger support software that facilitates collection-on-demand of final-data memory.
This feature is found in PC200W, PC400, LoggerNet, and RTDAQ software.
COM port
COM is a generic name given to physical and virtual serial communication ports.
COM1
When configured as a communication port, terminals C1 and C2 act as a pair to form Com1.
command
An instruction or signal that causes a computer to perform one of its basic functions (usually in CRBasic).
Glossary
95
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 multiple program statements separated by a <colon> (:).
CompactFlash
CompactFlash® (CF) is a memory-card technology used in some Campbell Scientific card-storage modules.
compile
The software process of converting human-readable program code to binary machine code. Datalogger user
programs are compiled internally by the datalogger operating system.
conditioned output
The output of a sensor after scaling factors are applied.
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.
constant
A packet of memory given an alpha-numeric name and assigned a fixed number.
control I/O
C terminals configured for controlling or monitoring a device.
CoraScript
CoraScript is a command-line interpreter associated with LoggerNet datalogger support software.
CPU
Central processing unit. The brains of the datalogger.
cr
Carriage return.
CRBasic
Campbell Scientific's BASIC-like programming language that supports analog and digital measurements, data
processing and analysis routines, hardware control, and many communication protocols.
CRBasic Editor
The CRBasic programming editor; supplied as part of LoggerNet, PC400, and RTDAQ software.
CRC
Cyclic Redundancy Check
CRD
An optional memory drive that resides on a memory card.
CS I/O
Campbell Scientific proprietary input/output port. Also, the proprietary serial communication protocol that occurs
over the CS I/O port.
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.
D
DAC
Digital to analog conversion. The process that translates digital voltage levels to analog values.
96
Glossary
data bits
Number of bits used to describe the data and fit between the start and stop bit. Sensors typically use 7 or 8 data
bits.
data cache
The data cache is a set of binary files kept on the hard disk of the computer running the datalogger support
software. 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 datalogger, the data are stored in the binary file for that datalogger. Various software
functions retrieve data from the data cache instead of the datalogger directly. This allows the simultaneous
sharing of data among software functions.
data output interval
The interval between each write of a record to a final-storage memory data table.
data output processing instructions
CRBasic instructions that process data values for eventual output to final-data memory. Examples of outputprocessing 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 to await the output trigger. The ultimate destination of data generated by data output
processing instructions is usually final-storage memory, but the CRBasic program can be written to divert to
variable memory by the CRBasic program for further processing. The transfer of processed summaries to finaldata memory takes place when the Trigger argument in the DataTable() instruction is set to True.
data output processing memory
SRAM memory automatically allocated for intermediate calculations performed by CRBasic data output
processing instructions. Data output processing memory cannot be monitored.
data point
A data value which is sent to final-storage memory as the result of a data-output processing instruction. Strings
of data points output at the same time make up a record in a data table.
data table
A concept that describes how data are organized in memory, or in files that result from collecting data in
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. The data table structure also resides in the data
cache, in discrete data files on the CPU, USR, CRD, and USB memory drives, and in binary or ASCII files that
result from collecting final-storage memory with datalogger support software.
datalogger support software
LoggerNet, PC400, and PC200W - these Campbell Scientific software applications includes at least the
following functions: datalogger communications, downloading programs, clock setting, and retrieval of
measurement data.
DC
Direct current.
DCE
Data Communication Equipment. While the term has much wider meaning, in the limited context of practical use
with the datalogger, it denotes the pin configuration, gender, and function of an RS-232 port. The RS-232 port
on the datalogger is DCE. Interfacing a DCE device to a DCE device requires a null-modem cable.
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.
Device Configuration Utility
Configuration tool used to set up dataloggers and peripherals, and to configure PakBus settings before those
devices are deployed in the field and/or added to networks.
DHCP
Dynamic Host Configuration Protocol. A TCP/IP application protocol.
Glossary
97
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.
Dim
A CRBasic command for declaring and dimensioning variables. Variables declared with Dim remain hidden
during datalogger operations.
dimension
To code a CRBasic program for a variable array as shown in the following examples: 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.
DNP3
Distributed Network Protocol is a set of communications protocols used between components in process
automation systems. Its main use is in utilities such as electric and water companies.
DNS
Domain name server. A TCP/IP application protocol.
DTE
Data Terminal Equipment. While the term has much wider meaning, in the limited context of practical use with
the datalogger, it denotes the pin configuration, gender, and function of an RS-232 port. The RS-232 port on the
datalogger is DCE. Attachment of a null-modem cable to a DCE device effectively converts it to a DTE device.
duplex
A serial communication protocol. Serial communications can be simplex, half-duplex, or full-duplex.
duty cycle
The percentage of available time a feature is in an active state. For example, if the datalogger is programmed
with 1 second scan interval, but the program completes after only 100 milliseconds, the program can be said to
have a 10% duty cycle.
E
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.
engineering units
Units that explicitly describe phenomena, as opposed to, for example, the datalogger base analogmeasurement unit of millivolts.
ESD
Electrostatic discharge.
ESS
Environmental sensor station.
excitation
Application of a precise voltage, usually to a resistive bridge circuit.
execution interval
The time interval between initiating each execution of a given Scan() of a CRBasic program. If the Scan()
Interval is evenly divisible into 24 hours (86,400 seconds), it is synchronized with the 24 hour clock, so that the
program is executed at midnight and every Scan() Interval thereafter. The program is executed for the first time
at the first occurrence of the Scan() Interval after compilation. If the Scan() Interval does not divide evenly into
24 hours, execution will start on the first even second after compilation.
98
Glossary
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
field will increment.
expression
A series of words, operators, or numbers that produce a value or result.
F
FAT
File Allocation Table - a computer file system architecture and a family of industry-standard file systems utilizing
it.
FFT
Fast Fourier Transform. A technique for analyzing frequency-spectrum data.
field
Final-storage data tables are made up of records and fields. Each row in a table represents a record and each
column represents a field. The number of fields in a record is determined by the number and configuration of
output processing instructions that are included as part of the DataTable() declaration.
File Control
File Control is a feature of LoggerNet, PC400, PC200W, Device Configuration Utility, and RTDAQ datalogger
support software. It provides a view of the datalogger file system and a menu of file management commands.
fill and stop memory
A memory configuration for data tables forcing a data table to stop accepting data when full.
final-storage data
Data that resides in final-data memory.
final-storage memory
The portion of SRAM memory allocated for storing data tables with output arrays. Once data are written to finaldata memory, they cannot be changed but only overwritten when they become the oldest data. Final-data
memory is configured as ring memory by default, with new data overwriting the oldest data.
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.
FLOAT
Four-byte floating-point data type. Default datalogger data type for Public or Dim variables. Same format as
IEEE4.
FP2
Two-byte floating-point data type. Default datalogger 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.
frequency domain
Frequency domain describes data graphed on an X-Y plot with frequency as the X axis. VSPECT vibrating wire
data are in the frequency domain.
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 finewire thermocouple, which changes output quickly with changes in temperature, is more likely to have a high
frequency response.
Glossary
99
FTP
File Transfer Protocol. A TCP/IP application protocol.
full-duplex
A serial communication protocol. Simultaneous bi-directional communications. Communications between a
serial port and a computer is typically full duplex.
G
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.
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.
ground
Being or related to an electrical potential of 0 volts.
ground currents
Pulling power from the datalogger wiring panel, as is done when using some communication devices from other
manufacturers, or a sensor that requires a lot of power, can cause voltage potential differences between points
in datalogger circuitry that are supposed to be at ground or 0 Volts. This difference in potentials can cause
errors when measuring single-ended analog voltages.
H
half-duplex
A serial communication protocol. Bi-directional, but not simultaneous, communications. SDI-12 is a half-duplex
protocol.
handshake
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.
hello exchange
The process of verifying a node as a neighbor.
hertz
SI unit of frequency. Cycles or pulses per second.
HTML
Hypertext Markup Language. Programming language used for the creation of web pages.
HTTP
Hypertext Transfer Protocol. A TCP/IP application protocol.
hysteresis
The dependence of the state of the system on its history.
Hz
SI unit of frequency. Cycles or pulses per second.
100
Glossary
I
I2C
Inter-Integrated Circuit is a multi-master, multi-slave, packet switched, single-ended, serial computer bus.
IEEE4
Four-byte, floating-point data type. IEEE Standard 754. Same format as Float.
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.
INF
A data word indicating the result of a function is infinite or undefined.
initiate comms
A name given to a processes by which the datalogger initiates communications with a computer running
LoggerNet. Also known as Callback.
input/output instructions
Used to initiate measurements and store the results in input storage or to set or read control/logic ports.
instruction
Usually refers to a CRBasic command.
integer
A number written without a fractional or decimal component. 15 and 7956 are integers; 1.5 and 79.56 are not.
intermediate memory
SRAM memory automatically allocated for intermediate calculations performed by CRBasic data output
processing instructions. Data output processing memory cannot be monitored.
IP
Internet Protocol. A TCP/IP internet protocol.
IP address
A unique address for a device on the internet.
IP trace
Function associated with IP data transmissions. IP trace information was originally accessed through the
CRBasic instruction IPTrace() and stored in a string variable. Files Manager setting is now modified to allow for
creation of a file on a datalogger memory drive, such as USR:, to store information in ring memory.
isolation
Hardwire communication devices and cables can serve as alternate paths to earth ground and entry points into
the datalogger for electromagnetic noise. Alternate paths to ground and electromagnetic noise can cause
measurement errors. Using opto-couplers in a connecting device allows communication 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 an accessory for use on the CS I/O port.
J
JSON
Java Script Object Notation. A data file format available through the datalogger or LoggerNet.
Glossary
101
K
keep memory
keep memory is non-volatile memory that preserves some settings during a power-up or program start up reset.
Examples include PakBus address, station name, beacon intervals, neighbor lists, routing table, and
communication timeouts.
keyboard/display
The datalogger has an optional external keyboard/display.
L
leaf node
A PakBus node at the end of a branch. When in this mode, the datalogger 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.
lf
Line feed. Often associated with carriage return (<cr>). <cr><lf>.
linearity
The quality of delivering identical sensitivity throughout the measurement.
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.
LoggerLink
Mobile applications that allow a mobile device to communicate with IP, wi-fi, or Bluetooth enabled dataloggers.
LoggerNet
Campbell Scientific's datalogger support software for programming, communication, and data retrieval between
dataloggers and a computer.
LONG
Data type used when declaring integers.
loop
A series of instructions in a CRBasic program that are repeated for a programmed number of times. The loop
ends with an End instruction.
loop counter
Increments by one with each pass through a loop.
LSB
Least significant bit (the trailing bit).
LVDT
The linear variable differential transformer (LVDT) is a type of electrical transformer used for measuring linear
displacement (position).
M
mains power
The national power grid.
manually initiated
Initiated by the user, usually with a Keyboard/Display, as opposed to occurring under program control.
102
Glossary
mass storage device
A mass storage device may also be referred to as an auxiliary storage device. The term is commonly used to
describe USB mass storage devices.
MD5 digest
16 byte checksum of the TCP/IP VTP configuration.
micro SD
A removable memory-card technology used in CR6 and CR1000X dataloggers.
milli
The SI prefix denoting 1/1000 of a base SI unit.
Modbus
Communication protocol published by Modicon in 1979 for use in programmable logic controllers (PLCs).
modem/terminal
Any device that has the following: ability to raise the ring line or be used with an optically isolated interface to
raise the ring line and put the datalogger in the communication command state, or an asynchronous serial
communication port that can be configured to communicate with the datalogger.
modulo divide
A math operation. Result equals the remainder after a division.
MSB
Most significant bit (the leading bit).
multimeter
An inexpensive and readily available device useful in troubleshooting data acquisition system faults.
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.
mV
The SI abbreviation for millivolts.
N
NAN
Not a number. A data word indicating a measurement or processing error. Voltage overrange, SDI-12 sensor
error, and undefined mathematical results can produce NAN.
neighbor device
Device in a PakBus network that communicate directly with a device without being routed through an
intermediate device.
Network Planner
Campbell Scientific software designed to help set up dataloggers in PakBus networks so that they can
communicate with each other and the LoggerNet server. For more information, see
https://www.campbellsci.com/loggernet.
NIST
National Institute of Standards and Technology.
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.
Glossary
103
NSEC
Eight-byte data type divided up as four bytes of seconds since 1990 and four bytes of nanoseconds into the
second.
null modem
A device, usually a multi-conductor cable, which converts an RS-232 port from DCE to DTE or from DTE to
DCE.
Numeric Monitor
A digital monitor in datalogger support software or in a keyboard/display.
O
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.
ohm
The unit of resistance. Symbol is the Greek letter Omega (Ω). 1.0 Ω equals the ratio of 1.0 volt divided by 1.0
ampere.
Ohm's Law
Describes the relationship of current and resistance to voltage. Voltage equals the product of current and
resistance (V = I • R).
on-line data transfer
Routine transfer of data to a peripheral left on-site. Transfer is controlled by the program entered in the
datalogger.
operating system
The operating system (also known as "firmware") is a set of instructions that controls the basic functions of the
datalogger and enables the use of user written CRBasic programs. The operating system is preloaded into the
datalogger at the factory but can be re-loaded or upgraded by you using Device Configuration Utility software.
The most recent datalogger operating system .obj file is available at www.campbellsci.com/downloads.
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 datalogger or a
peripheral to another device.
output array
A string of data values output to final-data memory. Output occurs when the data table output trigger is True.
output interval
The interval between each write of a record to a final-storage memory data table.
output processing instructions
CRBasic instructions that process data values for eventual output to final-data memory. Examples of outputprocessing 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 to await the output trigger. The ultimate destination of data generated by data output
processing instructions is usually final-storage memory, but the CRBasic program can be written to divert to
variable memory by the CRBasic program for further processing. The transfer of processed summaries to finaldata memory takes place when the Trigger argument in the DataTable() instruction is set to True.
output processing memory
SRAM memory automatically allocated for intermediate calculations performed by CRBasic data output
processing instructions. Data output processing memory cannot be monitored.
104
Glossary
P
PakBus Graph
Software that shows the relationship of various nodes in a PakBus network and allows for monitoring and
adjustment of some registers in each node. A PakBus node is typically a Campbell Scientific datalogger, a
computer, or a communication device.
PakBus®
A proprietary communication protocol similar to IP protocol developed by Campbell Scientific to facilitate
communications between Campbell Scientific instrumentation. A registered trademark of Campbell Scientific,
Inc.
parameter
Part of a procedure (or command) definition.
PC200W
Basic datalogger support software for direct connect. It supports a connection between computer and
datalogger and includes Short Cut for creating datalogger programs. Tools for setting the datalogger clock,
sending programs, monitoring sensors, and on-site viewing and collection of data are also included.
PC400
Datalogger support software that supports a variety of communication options, manual data collection, and data
monitoring displays. Short Cut and CRBasic Editor are included for creating datalogger programs. PC400 does
not support complex communication options, such as phone-to-RF, PakBus® routing, or scheduled data
collection.
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.
peripheral
Any device designed for use with the datalogger. A peripheral requires the datalogger to operate. Peripherals
include measurement, control, and data retrieval and communication modules.
PGIA
Programmable Gain Input Amplifier
ping
A software utility that attempts to contact another device in a network.
pipeline mode
A CRBasic program execution mode wherein instructions are evaluated in groups of like instructions, with a set
group prioritization.
PLC
Programmable Logic Controllers
Poisson ratio
A ratio used in strain measurements.
ppm
Parts per million.
precision
The amount of agreement between repeated measurements of the same quantity (AKA repeatability).
PreserveVariables
CRBasic instruction that protects Public variables from being erased when a program is recompiled.
print device
Any device capable of receiving output over pin 6 (the PE line) in a receive-only mode. Printers, "dumb"
terminals, and computers in a terminal mode fall in this category.
Glossary
105
print peripheral
Any device capable of receiving output over pin 6 (the PE line) in a receive-only mode. Printers, "dumb"
terminals, and computers in a terminal mode fall in this category.
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.
program control instructions
Modify the execution sequence of CRBasic instructions. Also used to set or clear flags.
Program Send command
Program Send is a feature of datalogger support software.
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.
public
A CRBasic command for declaring and dimensioning variables. Variables declared with Public can be
monitored during datalogger operation.
pulse
An electrical signal characterized by a rapid increase in voltage follow by a short plateau and a rapid voltage
decrease.
R
ratiometric
Describes a type of measurement or a type of math. Ratiometric usually refers to an aspect of resistive-bridge
measurements - either the measurement or the math used to process it. Measuring ratios and using ratio math
eliminates several sources of error from the end result.
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.
Final-storage data tables are made up of records and fields. Each row in a table represents a record and each
column represents a field. The number of fields in a record is determined by the number and configuration of
output processing instructions that are included as part of the DataTable() declaration.
regulator
A setting, a Status table element, or a DataTableInformation table element. Also 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.
resistance
A feature of an electronic circuit that impedes or redirects the flow of electrons through the circuit.
resistor
A device that provides a known quantity of resistance.
resolution
The smallest interval measurable.
ring line
Ring line is pulled high by an external device to notify the datalogger to commence RS-232 communications.
Ring line is pin 3 of a DCE RS-232 port.
ring memory
A memory configuration that allows the oldest data to be overwritten with the newest data. This is the default
setting for final-storage data tables.
106
Glossary
ringing
Oscillation of sensor output (voltage or current) that occurs when sensor excitation causes parasitic
capacitances and inductances to resonate.
RMS
Root-mean square, or quadratic mean. A measure of the magnitude of wave or other varying quantities around
zero.
RNDIS
Remote Network Driver Interface Specification - a Microsoft protocol that provides a virtual Ethernet link via
USB.
router
Device configured as a router is able to forward PakBus packets from one port to another. To perform its routing
duties, a datalogger 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.
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 computer communications is
quite rigid, but transparent to most users. Features in the datalogger that implement RS-232 communication
with smart sensors are flexible.
RS-485
Recommended Standard 485. A standard defining how two computing devices can communicate with each
other.
RTDAQ
Datalogger support software for industrial and real-time applications.
RTU
Remote Telemetry Units
Rx
Receive
S
sample rate
The rate at which measurements are made by the datalogger. 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
1 kHz will give a high sample rate but does not ensure the measurement has a high frequency response. A finewire thermocouple, which changes output quickly with changes in temperature, is more likely to have a high
frequency response.
scan interval
The time interval between initiating each execution of a given Scan() of a CRBasic program. If the Scan()
Interval is evenly divisible into 24 hours (86,400 seconds), it is synchronized with the 24 hour clock, so that the
program is executed at midnight and every Scan() Interval thereafter. The program is executed for the first time
at the first occurrence of the Scan() Interval after compilation. If the Scan() Interval does not divide evenly into
24 hours, execution will start on the first even second after compilation.
scan time
When time functions are run inside the Scan() / NextScan construct, time stamps are based on when the scan
was started according to the datalogger clock. Resolution of scan time is equal to the length of the scan.
Glossary
107
SDI-12
Serial Data Interface at 1200 baud. Communication protocol for transferring data between the datalogger and
SDI-12 compatible smart sensors.
SDK
Software Development Kit
SDM
Synchronous Device for Measurement. A processor-based peripheral device or sensor that communicates with
the datalogger via hardwire over a short distance using a protocol proprietary to Campbell Scientific.
Seebeck effect
Induces microvolt level thermal electromotive forces (EMF) across junctions of dissimilar metals in the presence
of temperature gradients. This is the principle behind thermocouple temperature measurement. It also causes
small, correctable voltage offsets in datalogger measurement circuitry.
semaphore
(Measurement semaphore.) In sequential mode, when the main scan executes, it locks the resources
associated with measurements. In other words, it acquires the measurement semaphore. This is at the scan
level, so all subscans within the scan (whether they make measurements or not), will lock out measurements
from slow sequences (including the auto self-calibration). Locking measurement resources at the scan level
gives non-interrupted measurement execution of the main scan.
send button
Send button in datalogger support software. Sends a CRBasic program or operating system to a datalogger.
sequential mode
A CRBasic program execution mode wherein each statement is evaluated in the order it is listed in the program.
serial
A loose term denoting output of a series of ASCII, HEX, or binary characters or numbers in electronic form.
Settings Editor
An editor for observing and adjusting settings. Settings Editor is a feature of LoggerNet|Connect, PakBus
Graph, and Device Configuration Utility.
Short Cut
A CRBasic programming wizard suitable for many datalogger applications. Knowledge of CRBasic is not
required to use Short Cut.
SI
Système Internationale. The uniform international system of metric units. Specifies accepted units of measure.
signature
A number which is a function of the data and the sequence of data in memory. It is derived using an algorithm
that assures a 99.998% probability that if either the data or the data sequence changes, the signature changes.
simplex
A serial communication protocol. One-direction data only. Serial communications between a serial sensor and
the datalogger may be simplex.
single-ended
Denotes a sensor or measurement terminal wherein the analog voltage signal is carried on a single lead and
measured with respect to ground (0 V).
skipped scans
Occur when the CRBasic program is too long for the scan interval. Skipped scans can cause errors in pulse
measurements.
slow sequence
A usually slower secondary scan in the CRBasic program. The main scan has priority over a slow sequence.
108
Glossary
SMTP
Simple Mail Transfer Protocol. A TCP/IP application protocol.
SNP
Snapshot file.
SP
Space.
SPI
Serial Peripheral Interface - a clocked synchronous interface, used for short distance communications,
generally between embedded devices.
SRAM
Static Random-Access Memory
start bit
The bit used to indicate the beginning of data.
state
Whether a device is on or off.
Station Status command
A command available in most datalogger support software.
stop bit
The end of the data bits. The stop bit can be 1, 1.5, or 2.
string
A datum or variable consisting of alphanumeric characters.
support software
Campbell Scientific software that includes at least the following functions: datalogger communications,
downloading programs, clock setting, and retrieval of measurement data.
synchronous
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
synchronous communication, this coordination is accomplished by synchronizing the transmitting and receiving
devices to a common clock signal (see also asynchronous).
system time
When time functions are run outside the Scan() / NextScan construct, the time registered by the instruction will
be based on the system clock, which has a 10 ms resolution.
T
table
Final-storage data tables are made up of records and fields. Each row in a table represents a record and each
column represents a field. The number of fields in a record is determined by the number and configuration of
output processing instructions that are included as part of the DataTable() declaration.
task
Grouping of CRBasic program instructions automatically by the datalogger compiler. Tasks include
measurement, SDM or digital, and processing. Tasks are prioritized when the CRBasic program runs in pipeline
mode. Also, a user-customized function defined through LoggerNet Task Master.
TCP/IP
Transmission Control Protocol / Internet Protocol.
Glossary
109
TCR
Temperature Coefficient of Resistance. TCR tells how much the resistance of a resistor changes as the
temperature of the resistor changes. The unit of TCR is ppm/°C (parts-per-million per degree Celsius). A
positive TCR means that resistance increases as temperature increases. For example, a resistor with a
specification of 10 ppm/°C will not increase in resistance by more than 0.000010 Ω per ohm over a 1 °C
increase of the resistor temperature or by more than .00010 Ω per ohm over a 10 °C increase.
Telnet
A software utility that attempts to contact and interrogate another specific device in a network. Telnet is resident
in Windows OS.
terminal
Point at which a wire (or wires) connects to a wiring panel or connector. Wires are usually secured in terminals
by screw- or lever-and-spring actuated gates with small screw- or spring-loaded clamps.
terminal emulator
A command-line shell that facilitates the issuance of low-level commands to a datalogger or some other
compatible device. A terminal emulator is available in most datalogger support software available from
Campbell Scientific.
thermistor
A thermistor is a temperature measurement device with a resistive element that changes in resistance with
temperature. The change is wide, stable, and well characterized. The output of a thermistor is usually nonlinear, so measurement requires linearization by means of a Steinhart-Hart or polynomial equation. CRBasic
instructions Therm107(), Therm108(), and Therm109() use Steinhart-Hart equations.
throughput rate
Rate that a measurement can be taken, scaled to engineering units, and the stored in a final-memory data
table. The datalogger has the ability to scan sensors at a rate exceeding the throughput rate. The primary factor
determining throughput rate is the processing programmed into the CRBasic program. In sequential-mode
operation, all processing called for by an instruction must be completed before moving on to the next instruction.
time domain
Time domain describes data graphed on an X-Y plot with time on the X axis. Time series data are in the time
domain.
TLS
Transport Layer Security. An Internet communication security protocol.
toggle
To reverse the current power state.
TTL
Transistor-to-Transistor Logic. A serial protocol using 0 Vdc and 5 Vdc as logic signal levels.
Tx
Transmit
U
UART
Universal Asynchronous Receiver/Transmitter for asynchronous serial communication.
UINT2
Data type used for efficient storage of totalized pulse counts, port status (status of 16 ports stored in one
variable, for example) or integer values that store binary flags.
unconditioned output
The fundamental output of a sensor, or the output of a sensor before scaling factors are applied.
110
Glossary
UPS
Uninterruptible Power Supply. A UPS can be constructed for most datalogger applications using ac line power,
a solar panel, an ac/ac or ac/dc wall adapter, a charge controller, and a rechargeable battery.
URI
Uniform Resource Identifier
URL
Uniform Resource Locator
user program
The CRBasic program written by you in Short Cut program wizard.
USR drive
A portion of memory dedicated to the storage of image or other files.
V
Vac
Volts alternating current.
variable
A packet of SRAM given an alphanumeric name. Variables reside in variable memory.
Vdc
Volts direct current.
VisualWeather
Datalogger support software specialized for weather and agricultural applications. The software allows you to
initialize the setup, interrogate the station, display data, and generate reports from one or more weather
stations.
volt meter
An inexpensive and readily available device useful in troubleshooting data acquisition system faults.
voltage divider
A circuit of resistors that ratiometrically divides voltage. For example, a simple two-resistor voltage divider can
be used to divide a voltage in half. So, when fed through the voltage divider, 1 mV becomes 500 µV, 10 mV
becomes 5 mV, and so forth. Resistive-bridge circuits are voltage dividers.
volts
SI unit for electrical potential.
VSPECT®
A registered trademark for Campbell Scientific's proprietary spectral-analysis, frequency domain, vibrating wire
measurement technique.
W
watchdog timer
An error-checking system that examines the processor state, software timers, and program-related counters
when the CRBasic program is running. The following will cause watchdog timer resets, which reset the
processor and CRBasic program execution: processor bombed, processor neglecting standard system updates,
counters are outside the limits, voltage surges, and voltage transients. When a reset occurs, a counter is
incremented in the WatchdogTimer entry of the Status table. A low number (1 to 10) of watchdog timer resets is
of concern, but normally indicates that the situation should just be monitored. A large number of errors (>10)
accumulating over a short period indicates a hardware or software problem. Consult with a Campbell Scientific
support engineer.
Glossary
111
weather-tight
Describes an instrumentation enclosure impenetrable by common environmental conditions. During
extraordinary weather events, however, seals on the enclosure may be breached.
web API
Application Programming Interface
wild card
A character or expression that substitutes for any other character or expression.
X
XML
Extensible markup language.
112
Glossary
Index
5
5V .................................................................. 87
A
accuracy factors....................................... 40, 79
auto self-calibration ........................................ 55
B
backup ........................................................... 62
band-rejection filter ........................................ 76
bandwidth ...................................................... 47
battery ........................................................... 59
voltage status ...................................................... 65
bridge resistance ............................... 35, 39, 40
bridge strain ................................................... 38
C
C terminals ...................................... 5, 9, 10, 87
programmable logic control ................................ 11
calibrating ................................................ 55, 83
clock .............................................................. 68
collecting data ................................................ 22
communication options ........................ 9, 12, 48
Ethernet ........................................................ 14, 15
internet ................................................................ 92
RS-232 ................................................................ 12
SDI-12 ............................................... 50, 51, 52, 53
SDM ...................................................................... 9
USB ..................................................................... 12
communication ports .................................. 8, 11
CS I/O ................................................................. 10
serial ................................................................... 48
communication protocols ............................... 47
DNP3 .................................................................. 49
Modbus ............................................................... 48
PakBus................................................................ 50
TCP/IP ................................................................ 49
collecting ............................................................ 22
historic ................................................................ 22
monitoring .......................................................... 21
viewing ............................................................... 22
data acquisition system ................................... 1
data records .................................................. 23
data storage .................................................. 26
data tables .................................................... 23
example program ............................................... 25
instructions ......................................................... 25
memory .............................................................. 70
datalogger clock ...................................... 13, 16
dataloggers
current status ............................................... 65, 66
maintenance ...................................................... 55
protection ........................................................... 59
resetting ....................................................... 65, 70
DataTableInfo................................................ 21
dessicant ....................................................... 59
differential measurements ....................... 32, 73
digital I/O ......................................................... 7
dimensions .................................................... 85
DNP3 ............................................................ 49
drives
formatting ........................................................... 70
E
earth ground .................................................... 7
edge counting................................................ 44
edge timing ................................................... 44
electronic noise ............................................. 75
electrostatic discharges ................................. 61
enclosures..................................................... 59
Ethernet .............................................14, 15, 92
virtual over USB ................................................. 13
configuring communications .......................... 12
Ethernet LEDs ............................................... 15
extra response time ................................. 13, 16
CPI port ......................................................... 10
CPU drive ...................................................... 28
CS I/O ............................................................ 10
csi password ...................................... 13, 56, 57
csipasswd ................................................ 56, 57
csipassword ................................................... 57
current measurements ................................... 33
field calibration .............................................. 83
file names...................................................... 84
file systems ................................................... 83
filter ............................................................... 76
first notch frequency ...................................... 76
flash memory................................................. 28
fN1 ................................................................ 76
formatting drives ............................................ 70
Ethernet ........................................................ 14, 15
USB ..................................................................... 12
D
data
F
G
G terminals ...................................................... 7
Index
113
ground terminals ...................... 7, 71, 74, 80, 86
O
H
offset voltages ....................................74, 79, 80
open collector ................................................ 43
open input detection ...................................... 75
OS updates ................................................... 62
high frequency signal measurements ....... 43, 91
historic data ................................................... 22
humidity protection......................................... 59
I
I2C ................................................................. 54
INF................................................................. 67
internal battery ............................................... 59
internet communications .......................... 49, 92
over USB............................................................. 13
L
LEDs
Ethernet .............................................................. 15
lightening protection ....................................... 61
lithium battery ................................................ 59
low-level ac measurements...................... 42, 91
LVTTL .............................................................. 9
M
maintenance .................................................. 55
mass .............................................................. 85
max time online........................................ 13, 16
measurements
0-20mA ............................................................... 33
4-20mA ............................................................... 33
current-loop ......................................................... 33
differential ..................................................... 32, 73
high frequency .................................................... 91
high-frequency signal.......................................... 43
low-level ac ................................................... 42, 91
period-averaging ................................................. 41
pulse ..................................... 41, 42, 43, 44, 45, 91
resistance................................................ 35, 39, 40
single-ended ................................................. 32, 73
strain ................................................................... 38
switch closure ..................................................... 91
thermocouple ...................................................... 40
vibrating wire ....................................................... 46
voltage ................................................................ 32
memory ......................................................... 26
allocation ............................................................. 26
insufficient ........................................................... 84
resetting .............................................................. 70
micro SD ........................................................ 28
Modbus .......................................................... 48
moisture protection ........................................ 59
mutli-drop network ........................................... 9
N
NAN ............................................................... 67
noise rejection ......................................... 17, 75
notch filter ...................................................... 76
114
Index
P
PakBus.......................................................... 50
PakBus encryption key ............................ 13, 16
password....................................................... 56
percent-of-reading ......................................... 79
period-averaging measurements ............. 41, 90
physical specifications ................................... 85
PLC ............................................................... 10
ports
communication ................................................8, 10
CPI ..................................................................... 10
CS I/O ................................................................ 10
Ethernet........................................................ 14, 92
RS-232 ......................................................... 10, 12
USB .................................................................... 12
power ...................................................6, 85, 87
12V ........................................................................6
5V ..........................................................................7
budgeting ........................................................... 62
ground ...................................................................7
I/O .........................................................................5
inputs.....................................................................5
noise................................................................... 75
output ....................................................................6
supplies .....................................................5, 62, 71
USB .......................................................................5
powerup.ini.................................................... 30
process names .............................................. 23
programmable logic control ........................... 10
programmed mode .................................. 50, 52
programs
creating .............................................................. 17
errors .................................................................. 69
run options ......................................................... 20
running on power-up .......................................... 30
sending............................................................... 19
sending without computer .................................. 30
protection ...................................................... 59
Public table ................................................... 21
pulse measurements .. 11, 41, 42, 43, 44, 45, 91
pulse width modulation .................................. 11
pulse-width modulation.................................. 92
R
RAM .............................................................. 26
ratiometric-resistance measurements...... 40, 90
recorder mode ......................................... 50, 52
resetting ........................................................ 70
resistance measurements ..................35, 39, 40
resolution ....................................................... 79
restore ........................................................... 62
RNDIS ........................................................... 13
RS-232 ................................................ 9, 10, 12
RS-485 ............................................................ 9
S
SCADA .......................................................... 48
scheduling collections .................................... 17
SDI-12 ..................................... 9, 50, 51, 52, 53
SDM ................................................................ 9
SE terminals .................................................... 5
security .................................................... 56, 57
security code ........................................... 13, 16
Seebeck effect ............................................... 80
sending a program ......................................... 16
sending OS .................................................... 62
sending programs .......................................... 19
sensors ............................................................ 2
serial ..................................................................... 9
wiring diagram .................................................... 17
serial communications ................................... 48
serial flash ..................................................... 28
serial peripheral interface............................... 54
settling errors ................................................. 77
settling time ................................................... 77
Short Cut ....................................................... 17
signal ground ................................................... 7
signal settling ................................................. 77
single-ended measurments ...................... 32, 73
sink limits ......................................................... 6
skipped records ............................................. 65
skpped scans ................................................. 65
source limits..................................................... 6
spark-gap protection ...................................... 61
specifications ................................................. 85
SPI................................................................. 54
station status ........................................... 65, 66
Status table.................................................... 21
strain measurements ..................................... 38
SW12................................................... 6, 10, 87
SW12 terminals
programmable logic control ................................ 11
switch closure .......................................... 43, 91
switching noise .............................................. 75
T
tables ............................................................. 23
DataTableInfo ..................................................... 21
Public ................................................................. 21
Status ................................................................. 21
TCP/IP .......................................................... 49
temperature measurements .......................... 40
terminals
C....................................................5, 10, 43, 44, 45
defined ..................................................................4
digital I/O ...............................................................7
ground .................................................7, 71, 74, 80
P ............................................................. 43, 44, 45
pulse............................................................. 41, 42
SE .........................................................................5
VX .........................................................................5
testing communication................................... 16
thermocouple measurements ........................ 40
time
keeping............................................................... 68
skew ................................................................... 69
stamps.......................................................... 68, 69
TOA5 ............................................................ 23
transparent mode .......................................... 51
troubleshooting.............................................. 65
TTL ................................................................. 9
U
updating OS .................................................. 62
USB ................................................. 5, 9, 12, 86
Ethernet.............................................................. 13
USR drive ...................................................... 27
V
variable out of bounds ................................... 65
vibrating wire measurements......................... 46
View Pro........................................................ 22
voltage measurements .................................. 32
improving ........................................................... 73
VSPECT........................................................ 46
VX terminals .............................................. 5, 88
programmable logic control................................ 11
W
watchdog error .............................................. 65
web access ................................................... 13
weight ........................................................... 85
wiring .............................................................. 4
power I/O...............................................................5
wiring diagram
0-20mA devices ................................................. 33
4-20mA devices ................................................. 33
sensors............................................................... 17
wiring panel ..................................................... 4
Index
115