instruNet Manual - OMEGA Engineering

instruNet Manual - OMEGA Engineering
MADE IN
SM
Extended Warranty
Program
User’s Guide
Shop online at
omega.com
e-mail: [email protected]
For latest product manuals:
omegamanual.info
instruNet
Analog/Digital Input/
Output System
OMEGAnet ® Online Service
omega.com
Internet e-mail
[email protected]
Servicing North America:
U.S.A.:
ISO 9001 Certified
Canada:
Omega Engineering, Inc., One Omega Drive, P.O. Box 4047
Stamford, CT 06907-0047 USA
Toll Free: 1-800-826-6342
TEL: (203) 359-1660
FAX: (203) 359-7700
e-mail: [email protected]
976 Bergar
Laval (Quebec), Canada H7L 5A1
Toll-Free: 1-800-826-6342
FAX: (514) 856-6886
TEL: (514) 856-6928
e-mail: [email protected]
For immediate technical or application assistance:
U.S.A. and Canada: Sales Service: 1-800-826-6342/1-800-TC-OMEGA®
Customer Service: 1-800-622-2378/1-800-622-BEST®
Engineering Service: 1-800-872-9436/1-800-USA-WHEN®
Mexico:
En Español: 001 (203) 359-7803
[email protected]
FAX: (001) 203-359-7807
e-mail: [email protected]
Servicing Europe:
Benelux:
Managed by the United Kingdom Office
Toll-Free: 0800 099 3344
TEL: +31 20 347 21 21
FAX: +31 20 643 46 43
e-mail: [email protected]
Czech Republic:
Frystatska 184
733 01 Karviná, Czech Republic
Toll-Free: 0800-1-66342
FAX: +420-59-6311114
France:
TEL: +420-59-6311899
e-mail: [email protected]
Managed by the United Kingdom Office
Toll-Free: 0800 466 342
TEL: +33 (0) 161 37 29 00
FAX: +33 (0) 130 57 54 27
e-mail: [email protected]
Germany/Austria: Daimlerstrasse 26
D-75392 Deckenpfronn, Germany
Toll-Free: 0 800 6397678
FAX: +49 (0) 7056 9398-29
United Kingdom:
ISO 9001 Certified
TEL: +49 (0) 7059 9398-0
e-mail: [email protected]
OMEGA Engineering Ltd.
One Omega Drive, River Bend Technology Centre, Northbank
Irlam, Manchester M44 5BD England
Toll-Free: 0800-488-488
TEL: +44 (0)161 777-6611
FAX: +44 (0)161 777-6622
e-mail: [email protected]
It is the policy of OMEGA Engineering, Inc. to comply with all worldwide safety and EMC/EMI
regulations that apply. OMEGA is constantly pursuing certification of its products to the European New
Approach Directives. OMEGA will add the CE mark to every appropriate device upon certification.
The information contained in this document is believed to be correct, but OMEGA accepts no liability for any
errors it contains, and reserves the right to alter specifications without notice.
WARNING: These products are not designed for use in, and should not be used for, human applications.
Ch 1 Installation
Table of Contents
F9 to update TOC
CHAPTER 1, INSTALLATION ............................................................................................................. 1-1
INSTRUNET FAMILY OVERVIEW .......................................................................................................1-1
COMPUTER REQUIREMENTS .............................................................................................................1-3
CONSTRUCTING YOUR NETWORK ....................................................................................................1-3
SOFTWARE INSTALLATION ...............................................................................................................1-5
HARDWARE INSTALLATION ..............................................................................................................1-8
VERIFYING THAT YOUR SYSTEM IS WORKING PROPERLY .............................................................1-9
INSTRUNET WORLD+ SOFTWARE LICENSE INSTALLATION ..........................................................1-11
CHAPTER 2, INSTRUNET TUTORIAL .............................................................................................. 2-1
RECORD WAVEFORMS IN 7 EASY STEPS .........................................................................................2-1
DIGITIZING DIRECTLY TO EXCEL .....................................................................................................2-4
WORKING WITH VB INSTRUMENT ....................................................................................................2-5
WORKING WITH VB SCOPE ...............................................................................................................2-6
DIGITIZING ANALOG SIGNALS INTO THE COMPUTER ......................................................................2-8
THE INSTRUNET DATA TREE ..........................................................................................................2-13
EXPLORE YOUR WORLD .................................................................................................................2-15
WORKING WITH SENSORS ...............................................................................................................2-20
WORKING WITH CALIBRATION, DIFFERENT SCALES, & MAPPING ...............................................2-24
WORKING WITH DIGITAL FILTERS .................................................................................................2-25
WORKING WITH VOLTAGE OUTPUT CHANNELS ...........................................................................2-29
WORKING WITH DIGITAL I/O CHANNELS ......................................................................................2-30
WORKING WITH I200 CONTROLLER DIGITAL TIMER I/O CHANNELS ...........................................2-31
WORKING WITH THE CONTROLLER TIME SINCE RESET CHANNEL ..............................................2-36
WORKING WITH MULTIPLE CONTROLLERS ...................................................................................2-37
NEXT STEP .......................................................................................................................................2-37
CHAPTER 3, CONNECTING TO SENSORS ...................................................................................... 3-1
CONNECTING A SENSOR DIRECTLY TO INSTRUNET ..........................................................................3-2
SENSOR REFERENCE..........................................................................................................................3-7
Single-ended Voltage Measurement .........................................................................................3-7
Differential Voltage Measurement ...........................................................................................3-8
Bridge Ratio Voltage Measurement .........................................................................................3-8
Current Measurement...............................................................................................................3-9
Resistance Measurement: Voltage Divider Circuit................................................................3-10
Resistance Measurement: Bridge Circuit...............................................................................3-11
Strain Gage Measurement: Voltage Divider Circuit .............................................................3-12
Strain Gage Measurement - Quarter Bridge.........................................................................3-13
Strain Gage Measurement - Half Bridge (Bending)...............................................................3-14
TC - 3
Ch 1 Installation
Strain Gage Measurement - Half Bridge (Axial)....................................................................3-15
Strain Gage Measurement - Full Bridge (Bending) ...............................................................3-16
Strain Gage Measurement - Full Bridge (Axial I)..................................................................3-16
Strain Gage Measurement - Full Bridge (Axial II) ................................................................3-17
Temperature Measurement (RTD) Voltage Divider1 .............................................................3-18
Temperature Measurement (RTD) Bridge Circuit .................................................................3-19
Temperature Measurement Thermocouple.............................................................................3-21
Thermistor...............................................................................................................................3-22
Temperature Measurement.....................................................................................................3-22
Load Cell Measurement..........................................................................................................3-23
Accelerometer Measurement ..................................................................................................3-25
Potentiometer..........................................................................................................................3-26
Measurement...........................................................................................................................3-26
SENSOR REFERENCE FOOTNOTES ...................................................................................................3-27
CHAPTER 4, A TUTORIAL FOR PROGRAMMERS........................................................................4-1
GETTING STARTED QUICKLY ............................................................................................................4-1
PROGRAMMING OVERVIEW ..............................................................................................................4-2
WORKING WITH ANY C COMPILER...........................................................................................4-8
GETTING STARTED WITH MAC METROWERKS CODEWARRIOR C/C++.........................................4-10
GETTING STARTED WITH MICROSOFT VISUAL BASIC ≥4.0 FOR ..................................................4-11
WINDOWS ........................................................................................................................................4-11
GETTING STARTED WITH MICROSOFT C/C++ ≥ 5.0 .......................................................................4-12
FOR WINDOWS .................................................................................................................................4-12
CHAPTER 5, INSTRUNET WORLD PROGRAM REFERENCE ....................................................5-1
THE NETWORK PAGE ........................................................................................................................5-2
THE RECORD PAGE ............................................................................................................................5-6
TEST PAGE .......................................................................................................................................5-17
THE SCRIPT PAGE ............................................................................................................................5-19
MENUBAR REFERENCE ....................................................................................................................5-19
CHAPTER 6, HARDWARE REFERENCE ..........................................................................................6-1
MODEL 200 PCI INSTRUNET CONTROLLERS ....................................................................................6-2
MODEL 230 PC-CARD INSTRUNET CONTROLLER ............................................................................6-4
MODEL 100, 100B, AND 100HC NETWORK DEVICES.......................................................................6-5
MODEL 300 POWER ADAPTOR ..........................................................................................................6-8
MODEL 311.X, 312.X, 322.X POWER SUPPLIES .................................................................................6-9
MODEL 330 ELECTRICAL ISOLATOR ...............................................................................................6-10
CHAPTER 7, CHANNEL REFERENCE ..............................................................................................7-1
CHAPTER 8, SETTINGS REFERENCE ..............................................................................................8-1
TC - 4
Ch 1 Installation
Chapter 1, Installation
This chapter explains how to install instruNet hardware and software onto your
computer, and how to verify that your instruNet System is operating properly.
With new systems it is recommend that you first do the Chapter 1 Installation, and
then proceed to the Chapter 2 Tutorial.
instruNet Family Overview
0-300 meters
instruNet
Controller
Network
Device
Network
Device
Overview
instruNet is a hardware and software product family that enables one to interface
computers such as the Apple Macintosh and Windows computers to common
laboratory and factory equipment for purposes of data acquisition and control.
instruNet utilizes a high speed network approach that is both low cost and flexible
for providing voltage inputs, voltage outputs, digital inputs, digital outputs, and
timer I/O to the computer.
Controllers
Each instruNet Network is controlled by a Network Controller board that installs
into a computer. A different controller board is used with each common bus
interface (e.g. PCI, PC-Card), yet they are all very similar internally. Each
Controller is an independent computer in itself that utilizes a powerful 32-bit
microprocessor and onboard RAM to control all aspects of data acquisition along
its network. One can install as many Controllers as desired, space permitting, since
each controller operates independently. Each network supports up to 32 Network
Devices. Each Device is a small box (e.g. 10cm x 12cm x 25cm) that is connected
in a daisy-chain configuration to form a chain of Devices. Each network can be up
to 300 meters long. All networks are anchored with an instruNet Terminator at the
far end, and an instruNet Controller at the near end. This makes instruNet a cost
effective method for designing large scale, high speed, multi-channel data
acquisition systems. The following table lists the instruNet Controllers described
in this manual.
1-1
Ch 1 Installation
Model
200
230
Controller
PCI Controller
Computer Required
Windows 95/98/Me/Nt/2k/Xp Computer
with PCI Rev ≥2.0 compliant, 32-bit, +5V
slot; or Macintosh OS >= 8 (must boot OS 9
if on OS >= 10.2 Mac) with PCI Slot.
PC-Card
PC-Card
2" x 3"
Windows 95/98/Me/2k/Xp (not NT)
Controller
Computer or Macintosh OS >= 8 (must boot
OS 9 if on OS >= 10.2 Mac) PPC/G3/G4/>
Powerbook computer (i.e. Models 1400,
2400, 3400, 5300, >=G3). Requires Type II
PCMCIA compliant ≥ v2.1 (or ≥ PC-Card
95) PC-Card slot.
Table 1.1 instruNet Controllers described in this Manual
Network
Devices
Model
100
100B
100HC
Bus
PCI
Size
7" x 4"
Network Devices typically provide voltage input channels, voltage output channels,
digital inputs and digital outputs. The following Network Devices are described in
this manual:
Voltage Inputs
Voltage Outputs
# of
Absolute
# of
Write
Read-back
Digital
Channels
Range
Accuracy Channels Accuracy Accuracy
I/O
16ch w/ +/- 5V
+/-1500µV
8ch with +/- 40 mV
+/- 3mV
8
screw +/-.6V
+/-150µV
4mA/1KpF
Bidirectional
terminal +/-80mV
+/-45µV
Drive
I/O Bits
access +/-8mV
+/-30µV
Capability
Same as #iNet-100, yet with 16 additional BNC connectors for 16se voltage inputs.
Same as #iNet-100, yet with voltage outputs that have 15mA/.01uF drive capability.
Table 1.2 instruNet Network Devices described in this Manual
instruNet
Software
instruNet includes software to interrogate, test, configure, and do I/O with all
network channels. This includes an application program called "instruNet World";
drivers; interfaces to C, and Visual BASIC. instruNet World and the instruNet
Driver can configure all I/O channels, store your settings, view digitized data in
real time, stream data to disk, and scroll through your waveform post-acquisition.
instruNet software runs on both a PC and a Macintosh OS >= 8 (must boot OS 9 if
on OS >= 10.2 Mac).
Free Updates
Free software and manual updates are available on the web at:
www.instrunet.com
1-2
Ch 1 Installation
Computer Requirements
The following table summarizes the computer required to run instruNet:
Model
200
230
230
Computer
Controller
Required
PCI
IBM PC or
Controller Compatible
≥ 80486
PC-Card
IBM PC or
Controller Compatible
≥ 80486
Macintosh
PC-Card
Controller PPC/G3/G4/>
OS
RAM
HD
Required Required Required
Windows ≥ 4MB
≥ 6MB
95/98/Me
free
Nt/2k/Xp
Windows ≥ 4MB
≥ 6MB
95/98/Me/2k/
free
Slot
Required
PCI Slot, ≥6.8", Rev
≥2.0 compliant, 32-bit,
+5V
Type II PC-Card Slot
with ≥ v2.1 PCMCIA
Xp (not NT)
compliant card services
OS >= 8 (must ≥ 4MB
≥ 6MB
Type II PC-Card Slot
boot OS 9 if
free
with ≥ v2.1 PCMCIA
on OS >= 10.2
Powerbook
compliant card services
Mac)
Table 1.3 Computer Requirements for instruNet Controllers
Constructing Your Network
instruNet hardware is 100% plug and play for all computers. instruNet does not
use dip switches, DMA, low memory, interrupts, and I/O addresses. All you need
to do is plug the Controller board into your computer, connect your network
devices, slap a terminator onto the end of your network and run the instruNet
World software. The instruNet driver automatically determines the physical
locations of all installed Controllers and Network Devices.
Please keep in mind the following when designing and constructing your network:
1. Install as many controllers as desired
The number of available slots determines the number of controllers (i.e.
networks) that can be installed, and simultaneously run, on one computer. The
software numbers each controller in the order that they are found in the
computer ("netNum" ranges from 1 to # of Controllers). Each controller
manages it's own network of devices. In most cases, only one controller is
necessary. The advantage of multiple controllers is that each is its own realtime machine, and more controllers can do more things simultaneously.
2. Install up to 16 Devices on each Network
One can attach, in daisy-chain configuration, up to 16 Network Devices to each
instruNet Controller. Each Network Device has two DB-25 connectors, one for
network input (male), and another for network output (female). To connect a
chain of Network Devices, one must connect each input connector to each
output connector via a DB-25 Male/Female cable. The Controller is attached to
the first device in the chain, and an instruNet Terminator is attached to the far
1-3
Ch 1 Installation
end of the chain. Due to the male/female polarization, the network cannot be
installed incorrectly with instruNet Male-Female cables.
3. Each Controller includes Timer I/O Channels
Each Controller (except iNet-230 PC-Card) provides 10 Timer I/O channels.
Each channel can be programmed as a digital input, digital output (0V/4V TTL
compatible), clock output, or period measurement input.
4. Each Controller includes one Terminator
One instruNet Terminator must be installed at the end of each network chain.
This terminator mates with the output connector of the last device. instruNet
Controllers include an instruNet Terminator, therefore they do not need to be
purchased separately. Caution: Do not use a SCSI Terminator in place of an
instruNet Terminator -- they are different.
5. Each Network Device includes one cable
Each instruNet Network Device is shipped with one 10foot DB-25 Cable
Male/Female cable for purposes of configuring your network.
6. You can purchasing your own cables
If you want a specific cable length, you can purchase your own DB-25 male to
DB-25 female, shielded, wired point-to-point (i.e. pin X to pin X) cables. We
recommend 24 gauge wire for > 4 meters; however 28 gauge is fine with ≤4m.
Twisted pairs are recommend for >4 meters with the following wires twisted: 1
& 14, 2 & 15, 3 & 16, 4 & 17, 5 & 18, 6 & 19, 7 & 20, 8 & 21, 9 & 22, 10 &
23, 11 & 24, 12 & 25 (these are physically next to each other in the connector).
Also, it is recommended that the drain wire (which is attached to the shield) be
connected to the housing and pin #1 (GND) on both connectors. For more
information on cables, please refer to Application Note #22, Third Party
instruNet Cable Suppliers; and Application Note #39, Use Low Capacitance
Cable to Maximize your instruNet Network Speed.
A supplier of high quality twisted pair, low capacitance, double-shielded cable
without connectors is Belden, Inc. The Belden Cable Part #8112 Low
Capacitance RS-485/RS-232 cable is available in 100ft, 500ft, and 1000ft
lengths with 12.5 Pairs and a copper braided shield. This cable features 24
gage wire, 41pF/meter between pairs, 72pF/meter between a wire and the
shield, and 78ohms/killometer wire resistance
7. Minimum Base System
One Controller and one Network Device is all you need to purchase to digitize
waveforms, save them to disk, and view them.
8. Maximum Sample Rate
As the physical length of the network increases, the maximum aggregate data
acquisition sample rate decreases from 166Ks/sec maximum with a short
network (e.g. 5 meters) to 4.15Ks/second aggregate with a long network (e.g.
300 meters).
1-4
Ch 1 Installation
This maximum aggregate rate applies to a batch of input channels. For
example one instruNet network can support 4 voltage input channels at a
maximum rate of 41.5Ksamples/sec for each channel (i.e. 166Ks/sec
throughput). The same network would allow 8 channels of voltage input to be
acquired at 20.075Ks/sec per channel. The maximum aggregate rate can be
increased by installing additional instruNet networks and controllers. For
example, two controllers could support 332Ks/sec aggregate throughput if run
simultaneously.
When the instruNet powers up, it empirically tests (i.e. it test the cable
impedance) of the network to determine its maximum throughput rate (i.e.
4.15K/sec to 166Ks/sec). The maximum rate is decreased by: additional
network devices, longer aggregate network cable length, non-twisted pair
cables, and thinner cable wire (e.g. 28 gauge instead of 24 gauge).
For more information on sample rates, please refer to Application Note #58 and
#117 (URL's www.instrunet.com#58, www.instrunet.com#117).
9. Turn power OFF when cabling
Always turn the computer and powered Network Devices Off before adjusting
network cables.
10. Large networks require external power supplies
The instruNet network cable provides power from the computer to the external
Network Devices. As the number of devices increases (more current drawn),
and the cable lengths increases (more voltage drops), it becomes increasingly
necessary to add an external power supply for the Network Devices. We
recommend adding an external power supply if your cable is > 50 meters, or for
every 4 Network Devices after your 3rd Device. In other words, only add an
external power supply if you have more than 3 network devices, or if your
network is longer than 50 meters.
Software Installation
To install instruNet SOFTWARE on a Windows 95/98/Me/Nt/2k/Xp/>
Computer:
1) Before installing instruNet Software >= v2.0 (which includes iW+) from CD or
from Internet URL www.instrunet.com/d: Turn OFF anti-virus (AV) software,
Disable any Anti-Virus "Automatically Launch on Startup" options, Restart
your computer, login as ADMINISTRATOR if on Windows Nt/2k/Xp/>,
Check that AV software is Off, and Make sure that other application programs
are Off. AV must be OFF after Restart since Installer may Restart several
times. This is Crucial, especially with older AV software that conflicts w/
modern Windows XP installers.
1-5
Ch 1 Installation
2) Install instruNet software Before installing physical i2x0 Controller card by
inserting instruNet CD into your computer (which automatically runs
"Setup.exe"), or by downloading Installer from "www.instrunet.com/d" (which
downloads "instrunet_web_setup.cab", opens it via WinZip, and then runs the
"Setup.exe" inside). If it asks you if you want to install the .Net Framework,
say Yes if running under Windows >=98 and <= 2K (not 95, not XP); and you
want to run programs VB Instrument, VB Scope or Direct To Excel; and you
don't mind waiting another 2 to 30min for the installer to run. Installation
might take up to 1 hour, especially with older computers that require more files.
If you become concerned your computer has frozen, please check your hard
disk light -- if it is blinking, you are Ok. When the instruNet installation is
complete, an "instruNet World" Icon appears on your desktop and an alert
notifies you of the success. At this time, it is safe to turn ON anti-virus
software. For information on installing instruNet hardware & drivers, please
continue with the below instructions.
To enable instruNet World+ (iW+) SOFTWARE on a Windows
98/ME/Nt/2k/Xp/> Computer:
For information on how to enable instrunet World+ (iW+) software, please see the
"instruNet World+ Software License Installation" discussion at the end of this
chapter, or refer to your "instruNet World+ (iW+) License x For Serial # y" sheet,
included with iW+.
To install instruNet i200 PCI or i230 Pcmcia HARDWARE on a Windows
95/98/Me Computer:
1) Make sure you are on a Windows 95/98/Me computer, Install the instruNet
software, as noted above, Turn computer POWER off, Install the physical
instruNet PCI or PCMCIA card, Attach the instruNet network devices, Attach
the instruNet terminator, Tighten the thumbscrews, and Turn the computer on.
2 It may ask you for a PCI or PCMCIA Card Driver on boot-up. Navigate via the
Browse/Other Locations button to the .inf/.vxd files on your computer. For
PCI, go to "Program Files \ instruNet \ internal \ PCI or PCMCIA Win95 Driver
\". Press Next to move through the installation process. It might say "Please
insert disk labeled 'Program files \ instruNet \ internal \ Pcmcia or Pci Win95
Driver \' directory". At this point, you must navigate to "Progra~1 \ instru~1 \
internal \ Pcmcia~1 \ iNt95Pcm.vxd" for Pcmcia or "Progra~1 \ instru~1 \
internal \ PciWin~1 \ iNet95.vxd" for PCI. You might need to type
"iNt95Pcm.vxd" for Pcmcia or "iNet95.vxd" for PCI into the file name field,
while "Progra~1 \ instru~1 \ internal \ Pcmcia~1 or PciWin~1 \" is selected in
the Directory area. When done, the card should be listed under "Data
Acquisition Cards" in the System "Device Manager". Reboot your computer
and then proceed to "To Verify Your System...", below.
To install instruNet i200 PCI or i230 Pcmcia HARDWARE on a Windows
Nt/2k/Xp/> Computer:
1-6
Ch 1 Installation
Make sure you are on a Windows Nt/2k/Xp computer (or later), Install the
instruNet software, as noted above, Turn computer POWER off, Install the physical
instruNet PCI or PCMCIA card, Attach the instruNet network devices, Attach the
instruNet terminator, Tighten the thumbscrews, and Turn the computer on. If it
asks for a .sys/.inf driver, navigate to "\ Program Files \ instruNet \ Internal \ PCI or
PCMCIA Win 2k-Xp Driver \" for PCI "inet.sys, inetpci.inf" or PCMCIA
"inetpcm.sys, inetpcm.inf". The i230 does not run under Win NT. Proceed to "To
Verify Your System...", below.
To install instruNet i200 PCI or i230 Pcmcia HARDWARE/SOFTWARE on a
Macintosh computer:
1) Make sure you are on an OS >= 8 Macintosh (must boot OS 9 if on OS >= 10.2).
The i200 requires a PowerPC/G3/G4/> Mac w/ 1 free PCI slot. The i230 requires a
Powerbook 1400/5300/2400/3400/G3/G4/> Mac with at least one free Type II
pcmcia slot.
2) Copy the Macintosh instruNet software to your computer (from the included
instruNet CD in the "Macintosh" directory, or from www.instruNet.com/d). If
the files are compressed (i.e. the file has an ".sea" or ".sit" suffix), uncompress
them with Stuffit Expander >= 5.1.13 from Aladdin Systems. Copy into your
Extensions folder (inside your System folder) "instruNet Driver (ppc)". If
working with SuperScope II, use the version of "instruNet Driver (ppc)"
included with instruNet.
3) Turn computer POWER off, install the instruNet PCI/Pcmcia card, attach
instruNet network devices, attach instruNet terminator, tighten thumbscrews,
turn cpu on, and proceed to "To Verify Your System...", below. On a
Powerbook 1400/5300 with an i230, it might say "please install driver". Please
ignore this alert, since the driver is inside instruNet World.
To Quickly Verify That Your System Is Working Properly:
To test instruNet, run "Start > Programs > instruNet > instruNet World" if on
Windows or run "instruNet World Mac" if on Macintosh, press the TEST tab at the
bottom of the window, press the SEARCH button and make sure your hardware is
listed (e.g. i200 card, i100 box). If the list is not correct, please see Note #69,
"Troubleshooting" (www.instrunet.com\trouble). Otherwise, if the list is correct,
please see the 1 page Note #209 "Getting Started Quickly with Windows"
(www.instrunet.com\start) document and then proceed to the instruNet User's
Manual Ch 2.
For details on verifying proper operation, please see the "To Verify …" discussion
later in this chapter.
To copy instruNet software From www.instrunet.com To non-networked
computers:
Surf to "www.instrunet.com/s" via Internet Explorer. Drag file
"instrunet_web_setup.cab" from your browser window to your hard disk -- to
download this file to your computer. Open this .cab file with decompression software
1-7
Ch 1 Installation
such as WinZip (a popular program for opening .zip files) and copy it's contents (i.e. a
"setup.exe" file) to the computer(s) on which you want to install instruNet Software
(i.e. via burning a CD, or via a local area network), and Install per the above
instructions.
Hardware Installation
To install an instruNet network, please:
1.
2.
3.
4.
5.
6.
7.
Read the previous "Constructing your Network" discussion. Before installing
hardware, please install software per the pervious instructions.
Turn OFF your computer.
Turn OFF all powered devices connected to your network.
Touch bare metal on your computer to discharge personal static electricity.
Remove the cover from your computer to gain access to the card slots, as
needed.
Remove the small I/O fence cover from the back of your computer, as needed.
If you require access to an available Controller Digital/Timer I/O Channel, run
a 34-wire ribbon cable from the Controller's 34pin header connector, out of the
computer, any way you can (e.g. through another slot opening), to the breakout
of your choice (e.g. a screw terminal block), as illustrated below:
Digital I/O & Clock
I/O Connector
Computer
ioNet
Controller
Computer Bus (PCI, Nubus)
DB-25 connector (male)
34-wire screw terminal
34-wire ribbon cable
Figure 1.4, Installing an instruNet Controller into a Computer
Install the instruNet controller(s) into the computer's expansion slot(s). If working
with a PCI Card, make sure the Controller connector is well seated and inspect this
connection with a strong light to make sure the printed circuit board fingers are
aligned with their mating connector pins.
9. Bolt the board metal I/O fence to the computer, as needed (some computers do
this). Please skip this step if tightening this bolt causes the card to not seat
well in its connector.
10. Put the cover back onto the computer, as needed.
11. Attach the external instruNet Network Devices in a daisy chain configuration,
as illustrated below.
8.
1-8
Ch 1 Installation
instruNet Terminator
DB-25 connector (male)
Computer
Network
Device #1
instruNet
Controller
DB-25 Cable
Network
Device #2
DB-25 connector (female)
Figure 1.5, instruNet Network
12.
13.
14.
15.
16.
Tighten all DB-25 thumbscrews until lightly snug.
Install an instruNet Terminator on the end of each network.
It is recommended that the user attach the instruNet instrumentation ground
(i.e. instruNet box and instruNet GND screw terminals) directly to Earth
ground with a 16gauge wire from the left-most GND screw on the instruNet
box, to the closest Earth ground (e.g. screw next to power socket). This will
reduce the chance of RFI coupling into the instruNet ground, and is required
if the user wants to meet EC and FCC RFI guidelines.
If working with an iNet-230 PC-Card, attach an external power supply (e.g.
iNet-311.x, 312.x, 322.x) to the PC-Card 5pin DIN connector. This supplies
power to the external network devices (i.e. not the PC-Card itself).
Turn the computer power ON and then Turn ON all powered devices attached
to the instruNet network.
Verifying That Your System Is Working Properly
Verify that your hardware and software is working in 5 easy steps:
1. Run the "instruNet World" application program ("instruNet World Mac"
on Macintosh, and "instruNet World Win32.exe" on a Microsoft Windows
computer), in the
instruNet directory. A
window will open,
similar to what is
pictured to the right. If
necessary, you might
need to click on the
Network tab at the
bottom of the window
to select the Network
page. If this window
opens, then you know
your instruNet driver
1-9
Ch 1 Installation
file is installed and working correctly. The list of channels shown in the
window's table will vary, depending on what instruNet hardware is connected.
If the instruNet window does not appear, then check the Software Installation
section at the beginning of this chapter to make sure that the software has been
installed correctly. If it appears that the software is installed correctly but not
functioning properly then see Application Note #69 Troubleshooting
(www.instrunet.com\trouble) and instruNet User's Manual Appendix I Trouble
Shooting.
2. Press the Test tab at the bottom of the window to select the Test page, and then
press the Search button at the top of the window. A report will print that lists
the controllers and network devices that are currently installed on your
computer. For example, the report below shows one Controller, and one Model
100 Network Device.
instruNet HARDWARE SEARCH RESULTS: Date & Time: 10/2/1997, 12:12:41
Net Dev Mod Device
---------------------------------------0
0
0
Mac OS Ver 7.5.3
0
0
1
instruNet Driver Version 1.24
0
0
1
instruNet World+ license Not Installed (costs extra)
1
0
1
PCI Controller #iNet-200 (slot #13, 4000KBD, 6us, 94%)
1
1
1
Device #iNet-100 (SN37532, Cal 9/28/97, Rev4, 30.99C, ...
If this does not match what you believe is installed on your network, then check
your hardware installation (cables, power, etc). Also, it is possible that the
instruNet Driver is older than the devices on your network, which means you
need the latest driver that recognizes these new devices. The instruNet Driver
is always listed as the 1st installed item.
3. Press the Test button at the top of the window to test your controllers and
devices, and to report any problems if found. The duration of the test can vary
from 1 to 120 seconds depending on the size of the networks, and the speed of
the computer. If no problems are found, a report similar to the one below is
printed in the window:
INSTRUNET QUICK TEST RESULTS:
Date & Time: 10/12/1995, 12:53:23
We ran 0.510029 million tests and did NOT hit 1 error.
4. Press the Big Test
button to run an
exhaustive test. An
alert similar to the one
on the right will appear
to communicate that the
computer will test all instruNet hardware until there is an error, or until you
press the mouse button down. It will test your network(s) all night long if you
let it. Press OK to begin the Big Test. Wait 20 seconds or longer. If an error
occurs while testing, an alert will appear and the error message will also be
printed in the window. Refer to Appendix II instruNet Error Codes for more
information on error codes, and Appendix I Trouble Shooting for tips on de-
1-10
Ch 1 Installation
bugging if necessary. If no error alerts appear, and you want to stop the test,
press the mouse button down and hold it down until the an alert appears
announcing the end of the test. Click OK to exit this alert. The test results are
printed in the window, in a format similar to what is shown below:
We ran 2.170272 million tests and did NOT hit 1 error.
Big Test is identical to Test, except it runs for a longer period of time and is
useful at finding intermittent problems that only occur once every minute, hour,
or day. Big Test can be run overnight for extensive testing of all hardware.
5. You are done! Your instruNet hardware and software is installed correctly and
running beautifully. Please see the 1 page Note #209 "Getting Started Quickly
with Windows" document (www.instrunet.com\start) and then proceed to the
instruNet User's Manual Chapter 2, Tutorial to learn more.
instruNet World+ Software License Installation
Overview
instruNet World (not +) software is available free of charge and included on the
instruNet CD with each i2x0 controller card (and at "www.instrunet.com/d"). The
"PLUS" version (referred to as "instruNet World+" or "iW+"), with more features,
is available at an additional charge under the following product numbers:
•
•
•
#iNet-350-SerialNumberOfController, instruNet World+ for pre-existing i2x0
controller card. One must specify the serial number of that controller on their
Purchase Order, since license codes are keyed to controller serial numbers.
#iNet-200P, instruNet PCI card and instruNet World+
#iNet-230P, instruNet PCMCIA card and instruNet World+
Since the PLUS software is included inside the NOT plus software, one only needs
to register the iW+ license code, described below, to enable the PLUS software
after installing the NOT plus software (i.e. after running the instruNet CD).
Licenses are issued for each individual controller cards and are keyed to the
controller's serial number. Subsequently, the PLUS features are only enabled in the
following cases:
•
•
•
iW+ Installation
A valid PLUS license code is installed, yet no controller card is installed.
A valid PLUS license code is installed, along with it's corresponding controller
card.
instruNet software is running in Demo mode and simulating a controller card.
To install an iW+ license on your computer and enable its powerful features on
Windows 98/Me/Nt/2k/Xp/> computers (iW+ is not supported on Macintosh):
1-11
Ch 1 Installation
1. In order to proceed, you must have purchased instruNet World+ (iW+) software
and have received an iW+ license code for your controller card. To learn more
about PLUS, please select "instruNet World+ Manual" in the "Help" menu
within instruNet World, or see Internet URL www.instrunet.com/plus.
2. Install instruNet software Version >= 2.0 onto your computer via the instruNet
CD, or from web URL "www.instrunet.com/d".
3. Launch the instruNet World software by double-clicking on its icon, or by
selecting START > Programs > instruNet > instruNet World.exe.
4. Select "Install instruNet World Script License…" in the Script menu.
5. Enter your license code (i.e. in the zz-ssssss-yyyyy format) into the license field
(note that "0" refers to number 0).
6. Press Ok, and a confirmation alert will appear. To view the status of your
license, press the Test tab at the bottom of the window and then press the
Search button. From this point forward, whenever you run instruNet World on
this computer (i.e. START > Programs > instruNet > instruNet World.exe), you
will be running iW+. Since the license code is stored in a file within the
System directory, installing newer versions of instruNet software will not
require repeating this procedure. To learn more about PLUS, please select
"instruNet World+ Manual" in the "Help" menu within instruNet World, or see
Internet URL www.instrunet.com/plus.
1-12
Ch 2 instruNet Tutorial
Chapter 2, instruNet Tutorial
This chapter is a step-by-step tutorial that shows the user how to navigate within
the world of instruNet. Controlling instruNet hardware can be done manually
though the free instruNet World application program, or through the programming
languages Visual Basic and C. This chapter deals exclusively with the easy-to-use
application program instruNet World application program while Chapter 4 covers
programming languages. instruNet World software allows you to set up and probe
your network, record waveforms, save them to disk, load them from disk, and view
them post acquisition.
This manual focuses on the buttons at the top of the instruNet World pages, yet
these functions can also be accessed in the menubar. For documentation on the
menubar and on instruNet World PLUS "iW+" (a version of instruNet World with
more features), please select "instruNet World+ Manual" in the "Help" menu
within instruNet World, or see Internet URL www.instrunet.com/plus.
Record Waveforms in 7 Easy Steps
This section explains how to record waveforms in several easy steps.
1.
Install your hardware and software per instructions in Chapter 1
If your instruNet World hardware and software is not installed, please install
it now, as described in Chapter 1.
2.
Run the instruNet World application program.
Locate the instruNet world application program within the instruNet folder on
your hard disk and then:
Windows:
Macintosh:
3.
Double-click on "instruNet World Win32.exe",
or run "Start > Programs > instruNet > instruNet World".
Double-click on the "instruNet World Mac" icon.
Select the Network Page.
instruNet World offers several Pages: Record, Network, and Test. Click on
the Network tab at the bottom of the window to select the Network page. The
Network tab will inverse black to indicate the Network page is selected.
2-1
Ch 2 instruNet Tutorial
Click here to select the Network Page
4.
Enable a Channel for digitizing.
A channel is enabled for digitizing by clicking on the small cell between the
addr and Value Input columns within the Network page, as illustrated below.
Once enabled, the channel will be digitized when the user presses the Start
button on the Record page. To disable a channel, one must click the digitize
on/off cell again. This digitize on/off cell is black or red when On, and white
when Off. Any number of channels can be selected for digitizing.
Please enable two voltage input channels (e.g. "Ch1 Vin+" and "Ch4 Vin+"
on the Model 100) for digitizing, as illustrated below. Voltage input channels
are typically labeled ChX Vin+ or ChX Vin-. These work identically when
doing single-ended voltage measurement (i.e. read a voltage between an input
terminal and ground), and are used as a pair when doing differential voltage
measurement (i.e. reading a voltage between 2 input channels). If instruNet
voltage input hardware is not installed, you will not be able to digitize. Also,
note that the contents of the Network page may vary depending on what is
installed on your computer.
To Enable/Disable a Channel for digitizing
5.
Attach a signal source.
If possible, attach a signal source to at least one channel's hardware input
terminal. For example, one might attach a Function Generator output to
the instruNet "Ch1 Vin+" input terminal, and the Function Generator's
ground to the instruNet "AGND" terminal. It is not necessary to connect
a signal source to do the tutorial, however, the displayed waveforms are
more interesting if a signal is applied; otherwise, you get a flat line at
0Volts.
6.
Select the Record Page.
Select the Record page by clicking on the Record tab at the base of the
window, as illustrated below.
Click here to select Record Page
2-2
Ch 2 instruNet Tutorial
7.
Tell instruNet to start digitizing.
Click the Start button at the top of the window to tell instruNet to record and
display channels that have been enabled for digitizing (e.g. "Ch1 Vin+").
You should see your waveforms move across the screen as they are digitized
in real-time, as illustrated below.
Click Start to start recording, Stop to stop recording
8.
Tell instruNet to stop digitizing
Click the Stop button to stop the digitizing process.
9.
Save your waveforms to disk
Click the Save button to save your waveforms to disk. When the save
dialog appears, type a name and choose a convenient location to save the
data. Saving does not specify a file name, but rather a folder name in
which all acquired waveforms and a preferences file are saved. For
example, if you digitized 2 waves and then clicked Save, 3 files would be
stored in your: one named "instruNet.prf" that contains the Field settings,
and two files that have the same name as the two channels, that contain
the wave data.
10.
Record again
Click the Start button to start recording again, and then click the Stop
button after a few moments.
11.
Load your saved waves from disk
Click the Open button to load in the previously saved waves from disk. A
File open dialog will appear, and it is here that you must select one of your
previously saved files (e.g. "instruNet.prf", "Ch1 Vin+" or "Ch4 Vin+").
After your waves are loaded in, they should appear in their displays .
2-3
Ch 2 instruNet Tutorial
Digitizing Directly To Excel
If you want to learn how to digitize in instruNet World, and then save a text file to
be loaded by a spreadsheet program, post-acquisition, please refer to Appendix III.
If you want to digitize into a spreadsheet, while data is being acquired, please
consider the Direct To Excel program, described here. Note that Direct To Excel
requires that an iW+ license be installed on your computer.
• In order to run Direct To Excel, All of the following must be installed on your
computer. If this is not the case, please proceed to the next section.
Windows Excel version >= 8.0 (i.e. Microsoft Office >= 97)
Windows >= 98 (not Windows 95, not Macintosh)
iW+ license (see www.instrunet.com/plus for details)
Windows .Net Framework (which is included with the instruNet
software, and is included automatically on Windows >= XP computers)
o instruNet software >= 2.0 (7/1/2003), available at www.instrunet.com/d
o
o
o
o
If you are not sure these requirements have been satisfied, try running the Direct
To Excel program, as described below, and if it runs ok, then you are probably
ok.
• Exit instruNet World and select under the Windows START menu: Programs /
instruNet / Application Software / Direct To Excel / Direct To Excel.exe. This
will run a program (shown below) written in Visual Basic; the source code of
which is currently installed on your hard disk. You are welcome to modify it.
• Press the Channels button, select 2 channels for digitizing (i.e. click in small
rectangle after channel address, it will turn red), and close the instruNet Network
window.
• Press the Start button and watch a new spreadsheet window appear and fill with
instruNet data, as shown below. When finished, you can save or delete the
Excel spreadsheet file.
2-4
Ch 2 instruNet Tutorial
• To learn more, please press the Help button.
• Close the Direct To Excel program by clicking in the upper right corner.
Working with VB Instrument
• We will now run a Windows program called "VB Instrument" that implements a
strip chart/oscilloscope recorder for 1 to 16 channels. It is similar to instruNet
World, yet is written in Visual Basic and the source code is installed on your
computer. You are welcome to modify it. If you are on a Macintosh, please
proceed to the next section.
• Exit any currently running instruNet software and select under the Windows
START menu: Programs / instruNet / Application Software / VB Applications /
VB Instrument.exe.
• Press the Channels button, select 4 channels for digitizing (i.e. click in small
rectangle after channel address, it will turn red), and close the instruNet Network
window.
• Press the Start button and watch the data appear in the window, as shown below.
2-5
Ch 2 instruNet Tutorial
• To learn more, please press the Help button.
• Close the VB Instrument program by clicking in the upper right corner.
Working with VB Scope
• We will now run a similar Windows program (written in Visual Basic, source
code included) called "VB Scope". It implements a 2 channel strip chart
recorder / oscilloscope, XY Record, and Spectrum Analyzer. If you are on a
Macintosh, please proceed to the next section.
• Exit any currently running instruNet software and select under the Windows
START menu: Programs / instruNet / Application Software / VB Applications /
VB Scope.exe.
• Press the Start button and watch the data appear in the window, as shown below.
Ch1 and Ch2 timewaves are shown in the left-most display, the frequency
spectrum of Ch1 is shown in the upper-right display, and an XY plot of Ch1 and
Ch4 are shown in the lower-right display.,
2-6
Ch 2 instruNet Tutorial
• To learn more, please press the Help button.
• Close the VB Scope program by clicking in the upper right corner.
2-7
Ch 2 instruNet Tutorial
Digitizing Analog Signals into the Computer
The Setup button at the top of the Record page opens a dialog box that effects
the manner in which waves are recorded.
• Click the Setup button to open the Setup dialog, as illustrated in Figure 2.1.
Figure 2.1 The Record Setup Dialog
The Setup dialog is used to set the base sample rate, the number of points to be
acquired per Scan, the number of Scans to be acquired and the recording mode (i.e.
oscilloscope or strip chart recorder). All instruNet Networks are set up with one
base sample rate (i.e. number of points digitized per second) and individual
channels can have sample rates less than or equal to the base sample rate. This
allows, in effect, each channel to have its own sample rate.
The Sample Rate field sets the base sample rate. The Pts Per Scan field determines
the amount of data to be collected in each Scan. The No. of Scans sets the number
of Scans to be acquired. The Scan Mode popup has three choices: Strip Chart,
Oscilloscope, and Oscillo Queued. Strip Chart is selected for continuous strip chart
recorder mode and Oscilloscope or Oscillo Queued are selected for oscilloscope
mode. Refer to the Oscilloscope or Strip Chart section of Chapter 5 for a full
description of these modes.
instruNet Networks are self-configuring and on startup determine the maximum
rate at which data can be transferred. This rate is displayed after pressing the
Timing button, in the Network BPS field, in units of bits per second. 4 million bits
per seconds is the fastest, and 100Kbps is the slowest. This rate slows down with
networks that have many Devices and long network cables (i.e. >100ft).
2-8
Ch 2 instruNet Tutorial
• Select Oscilloscope in the Scan Mode popup and set the Pts Per Scan field to
100. 100 points at 1000s/sec will take .1 seconds to acquire. Leave the rest of
the Dialog in its default settings, and click OK to return to the Record Page.
• Click the Start button to begin digitizing.
Notice how 0.1 second long waveforms continuously appear on the screen, in a
manner similar to an Oscilloscope. Before, we were in Strip Chart mode where
these segments were continuous with respect to each other. We are now in
Oscilloscope mode. To learn much more about digitizing, please refer to the
Record page discussion in Chapter 5, instruNet World Reference.
• Click the Stop button to stop
digitizing, and then click on the
top display's channel name label
at the right edge of the display.
The Display dialog will open.
Choose General in the Settings
popup. Enter the value 20 in the
% samp rate field as shown to
the right and press OK.
This will cause the top channel to be digitized at 20% of the master sample rate, or
200s/sec. The channel in the lower displays will continue to run at the master
sample rate of 1000s/sec.
• Click the Start button to begin digitizing, and then click Stop after a few
moments.
Notice how the wave in the top display contains fewer points, due to its
reduced sample rate, as illustrated to the left.
Trigger Modes
• Click the Setup button at the top of the Record page, and then click the Trigger
button to open the Trigger dialog, as shown in Figure 2.2.
instruNet World allows triggering from any channel on either a low-to-high or
high-to-low transition through a threshold value. The threshold is specified in
the Thresh EU field, and the trigger direction is specified in the Slope field (i.e.
low-to-high, or high-to-low). The channel to trigger from is specified by its
network address in the Trig Net#, Trig Dev#, Trig Mod# and Trig Chan# fields.
Three trigger types are allowed, as specified in the Trigger field: Off, Auto and
Norm. If Off is selected, data acquisition begins as soon as the Start button is
pressed in the Record Page. If Auto is selected, data acquisition begins after
the trigger criteria is met, but if the trigger condition is not met within a second
or so, the recording begins anyway. If Norm is selected, instruNet waits until
the trigger condition is met, indefinitely of necessary.
2-9
Ch 2 instruNet Tutorial
Fig 2.2 The Trigger Dialog
• Enter the address of a channel to trigger from into
the Trig Net#, Trig Dev#, Trig Mod# and Trig
Chan# fields. If you are not sure of a channel's
address, go back to the Network Page and look at the Channel and Addr column
for the channel you want to trigger from. The address for the two channels
shown in the above figure would be {1,1,1,1} and {1,1,1,4}. For example, if
you wanted to trigger from channel Ch4 Vin+, you would enter the following
values: 1 into Trig Net #, 1 into Trig Dev#, 1 into Trig Mod#, and 4 into Trig
Chan#.
• Select Auto in the Trigger popup, type a reasonable threshold voltage into
the Threshold EU field (e.g. 1V) and then select Rising or Falling in the
Slope popup. Click OK to exit the Trigger Dialog, click OK to exit the
Setup Dialog and then click the Start button to begin recording.
The waveforms should appear on the screen, with the beginning of each Scan
synchronized to the trigger event. If the signal applied to the trigger channel
does not periodically cross the threshold voltage, Auto trigger will digitize
anyway every second or so.
• Press Stop when you are done acquiring.
To learn more about Triggering, please refer to the Record page discussion in
Chapter 5.
• Click the Setup button at the top of the Record page to open the Record
Setup dialog, as shown in Figure 2.1.
Display
Options
The Horiz Scale field sets the display horizontal scale in seconds-per-division. If
set to Auto, instruNet picks a horizontal scale that is appropriate based on the
sample rate and number of data points being acquired. This popup is also provided
at the lower right of the Record page when iW+ is installed.
The Plot popup is used to set the drawing mode to plot Dots or Lines (i.e. light one
pixel for each data point, or connect these data points with lines), and the Grid
2-10
Ch 2 instruNet Tutorial
popup (accessed by pressing the Record button in Setup dialog) selects whether or
not to overlay a grid on each display.
Viewing
Many Channels
The Disp Height field sets the minimum height of each display in the
Record page, in pixels. If the number of waveforms being digitized is
greater than the available space on the screen, only a subset are
displayed, and the vertical scrollbar selects that set. For example, if the
Record page is 1000 pixels high, the Disp Height field is 100, and one
is digitizing 512 channels (the maximum amount); only 20 would be shown at one
time, and the vertical scrollbar would select that set of 20. In another example, if
the window was 640 pixels high, one was digitizing 32 channels, and one wanted to
see all channels at once; one would need to set the Disp Height field to 20 (i.e. 20
pixels * 32 channels = 640pixels).
Another technique is to hide individual displays by setting the Display View field
to Hide for each channel that you do not want a Display in the Record page. One
does this by opening the channel options dialog for each channel you want to hide,
select the Display setting, and then set the Display View field to Hide. If you want
to view channels numerically, then please consider Panel Meters, which are only
available in iW+ (described at www.instrunet.com/plus).
Time Of Day or
Relative Time
The Horizontal Label field allows one to show either Relative time or
Time of Day in the Record page horizontal timescale, as illustrated below.
Relative time shows the number of seconds since starting the digitization at 0
seconds. Time of Day shows the time of day, as known by the computer's clock.
For example, if you start digitizing at 1:05 am on Feb 1, 2003, it will show "0117,
2/1/03" 12 minutes later. Post-Acquisition, one can change this field to view the
data with either timescale format. Displaying Time of Day requires instruNet
World PLUS (iW+).
Time Relative to start of digitization, left edge corresponds to 0 secs
Time of Day, e.g. first grid corresponds to May 27, 2003, 3:51pm + 15 seconds
Digitize Into
Ram or File
The Digitize Into popup has 2 primary settings: To Ram Buffer, which saves
digitized data into RAM; and To File, which digitizes data directly to disk. If
Digitize Into is set to To File, instruNet automatically prompts the user for a
folder name every time a recording session is initiated with the Start button.
The waveforms are then saved to this folder while they are recorded. One can
then scroll through these long disk-based waveforms (e.g. 20M points per
channel) via the horizontal scrollbar. Any waves saved to disk using the To
File option can be opened and scrolled through with the Record Page's Open
button.
2-11
Ch 2 instruNet Tutorial
The File Type field determines the file format for the saved data, and is set to
one of Binary, Binary Merge, Text, or Text Merge. For a detailed description
of each format, please see File Type Application Notes.
• Select Lines in the Plot popup, select Off in the Grid popup, select "Strip Chart"
in the Scan Mode popup and, set the Pts per Scan field to 10000 to set the buffer
size of an intermediate RAM buffer that holds data before it is sent to disk
(10000 points at 1Ks/sec is a comfortable size). Set the Digitize Into popup to
"To File", and select 0.5 secs/div in the Horiz Scale popup. Click OK to exit the
dialog. Click Start to begin recording. When the File save dialog appears, type
a folder name and select a location for the waveforms that are about to be
"spooled" to disk.
• After a minute or so, press the Stop button to stop digitizing. Scroll through
your waveforms via the horizontal scrollbar. Notice that the computer goes to
your hard disk periodically to automatically load in information from disk.
RAM-Based
Digitizing
It is recommended that one Digitize Into RAM if your RAM is large enough.
RAM based digitizing is easier, since data in RAM can easily be saved in different
file formats, is easily loaded back into RAM from disk to be saved to disk in
another file format, and supports faster digitizing rates. Due to these advantages,
we recommend digitizing directly To Ram unless your RAM is not large enough to
hold the data. To digitize into RAM, set the Digitize Into field to "To Ram
Buffer", set the No Of Scans field to 1, and then use the Pts Per Scan field to
determine how long you digitize. If you digitize multiple scans directly To Ram,
data is overwritten in the RAM buffer and lost; therefore, we set the No Of Scans
field to 1. After digitizing into RAM one can press the Save button in the Record
page to save the data in the RAM buffer to disk in the format specified by the File
Type field. To transfer data to another software package, one typically sets File
Type to "Text Merge". This causes a file named "Excel Waveform Data.txt" to be
saved to disk that is easily opened by a spreadsheet, with each channel in its own
column. To save RAM based data in a compact fast format, we recommend File
Type "Binary Merge". To calculate the amount of RAM used to hold your data,
multiply the number of points, by the number of channels, by 4bytes-per-point.
For example, 3 channels of 10K points each would consume 120KBytes of RAM
(120KB = 4 * 3 * 10000).
File-Based
Digitizing
It is recommended that one Digitize Into File for bigger-than-RAM data, yet
one must consider how they will process the huge disk-based file. To Digitize
Into File, set the Digitize Into field to "To File", set the File Type field to
"Binary Merge", set the Sample Rate field to the desired points-per-second-perchannel, set the Pts Per Scan field to a nominal value (e.g. 5000) to set the
intermediate RAM buffer size, and then set the No Of Scans field to the number
of RAM buffers of data that are collected. For example, digitizing 1000 scans
of 5000pts-per-scan data digitized at 1000pts-per-sec will spool to disk a total
of 5M points over a 5Ksec period. When the Start button is pressed in the
Record page, it will prompt you for a file name before digitizing, and send the
data directly to disk.
2-12
Ch 2 instruNet Tutorial
The main issue, when digitizing directly To File is, "How are you going to deal
with all that data on disk?". instruNet World will not allow you to load it into
ram (since file based data is typically too large to fit into ram) and then save it
back out in another file format. It will only allow you to scroll though and view
the data (it automatically pages in segments from disk, as needed, for display).
And to digitize To Disk quickly, you need to use the Binary Merge File Type,
which interlaces all channels into one file, in 32bit floating point form. There
is physically no other way to spool to disk at fast rates without saving in this
manner. Therefore, to process a large disk based stream, one typically needs a
software package that interprets 32bit floating point interlaced data. For details
on this file format, please the File Format Application Notes.
If you want to save data to a spreadsheet program, post-acquisition, please refer
to Appendix III. If you want to digitize directly to a spreadsheet, while
acquiring data, please see the Digitizing Directly to Excel discussion, later in
this chapter.
To learn more about Setup Options, please refer to the Record Page discussion in
Chapter 5.
• Try various options and settings to gain some familiarity with the wonder world
of instruNet World. Some things to try are listed below:
- Press the Start button to start recording again.
- Press the Save button to save the digitized waves to disk (if they are RAM
based).
- Press the Open button to load previously recorded waveforms from disk.
- Press the Setup button to adjust the sample rate and number of points that are
digitized when the Start button is pressed.
- Press the Trigger button within the Setup Dialog to adjust the trigger options.
- Press the Network tab to select the Network page, and then turn on other
channels for digitizing by clicking on their digitize on/off cells.
The instruNet Data Tree
instruNet stores field settings in a hierarchical data tree illustrated in figure 2.4.
2-13
Ch 2 instruNet Tutorial
Network #
{0...32}
Device #
{0...32}
Module #
{1...32}
Channel
# {1...}
Setting Group
# {-32K...32K}
Field
Figure 2.4 Network Hierarchy for instruNet
To access a piece of information, you must supply an address within this data tree.
This address consists of 6 parameters, as described below:
2-14
Network Number
If 0, this refers to the Driver itself (e.g. plot lines or dots in the
Record displays); otherwise, this number refers to an instruNet
Controller board, where the first board found in the computer
is designated Network Number 1, the 2nd board found is
Network #2, etc.
Device Number
This refers to hardware devices (e.g. Model 100) attached to
an instruNet Controller board, where the hardware Device
closest to the Controller is Device #1, the next device is
Device #2, etc.
Module Number
This refers to the module within a hardware device. At this
time, all Devices have only 1 module that is referred to as
Module #1.
Channel Number
This refers to a specific channel in a hardware device. Each
channel typically corresponds to a physical wire somewhere,
such as a voltage input, voltage output, digital input, or digital
output. For example, in the Model 100, the screw terminal
marked "Ch1 Vin+" is Channel #1 and is a voltage input.
Setting Number
Each channel includes different Settings areas such as:
lowpass filter settings, highpass filters settings, Hardware
settings, etc. It is here that one selects a settings group (e.g.
Lowpass Filter fields have a Settings Number of -9).
Field Number
This is the Field Number {1..8} within a settings group. For
example, in the Lowpass Filter settings group, the cut-off
frequency in Hertz is stored in Field #5.
Ch 2 instruNet Tutorial
The instruNet World user navigates within this data tree via the Probe dialog,
described in the next discussion. instruNet World does not require the user to
know about Setting numbers and Field numbers since all items are defined using
popups and edit fields. The programmer, on the other hand, must supply 6
numbers to a subroutine to read and write to any field on the instruNet data tree.
The Network page shows the current Field settings for each channel in a tabular
(i.e. spreadsheet) format, and is also a useful tool for navigating around the
instruNet data tree. The data tree maintains any changes you make until you Reset
the network via the Reset button, reset the computer, or load in new setting from
disk via the Restore or Open buttons at the top of the Network page. In many
cases, a user will set the fields as needed, stored them to disk, and then reload them
when instruNet world is first opened.
Explore Your World
• Exit all instruNet software and run instruNet World.
• Select the Network page by pressing the Network tab at the bottom of the
window.
• Press the Reset button at the top of the window to reset all Fields in the Data
Tree. Press OK when a dialog asks for confirmation.
Figure 2.5 illustrates how information is organized in the Network page. The
channels that are displayed on your computer will vary depending on what
hardware is installed; therefore, don't worry if your screen is a little different from
the Figures.
Channels
Channel #
Network #
Device #
Module #
Fields
Figure 2.5 Partial view of the Network Page
2-15
Ch 2 instruNet Tutorial
The Network
Page
Each row in the Network page corresponds to an input or output channel,
which is often associated with a physical sensor in the real world. Each
channel has a {Network, Module, Device, Channel} address both
within the software data tree and the physical outside world. This address is
shown in the first 4 columns of the Network page. The first column indicates
the Channel name and number. For example, "Ch1 Vin1+" is Channel #1 and
the channel name is "Ch1 Vin1+". Columns #2 through #4 indicate the
channel's Network #, Device # and Module #, which correspond to a physical
address.
The column labeled "Value Input" depicts the current real-time value (input or
output) of the channel, in engineering units. All columns to the right of the
Value Input column are Fields that specify the type of signal connected to the
channel and how it is being read. The horizontal and vertical scroll bars are
used to move around and make changes to the tables contents. To change a
Field's setting, one can click on its cell and then change its value. For example,
to change the name of channel Ch1 Vin1+, one would click on the "Ch1
Vin1+" cell.
• Click on any cell in the Units Label column to open the Probe dialog, as shown
in figure 2.6.
Settings popup
Network #
Device #
Module #
Channel #
Fields for General settings area
Figure 2.6 The Probe Dialog
2-16
Ch 2 instruNet Tutorial
The Probe
Dialog
Using the Probe dialog, any Field within the instruNet Data Tree can be viewed
or modified. The upper-most 4 popup menus specify a channel address (i.e.
Network, Device, Module, Channel), the Settings popup specifies a Setting
group (e.g. General, Lowpass Filter, Highpass Filter, etc), and the Settings area
shows between 1 to 8 Fields depending on the Settings group selected.
For example, in Figure 2.6, we are viewing the General settings for channel Ch1
Vin+, which is physically connected to the 1st Device (a Model 100) attached to
the 1st Controller (i.e. Network), which is plugged into computer slot #12. The
General settings group contains 4 Fields: Value Input, Units Label, User Name, and
% Sample Rate.
The Value Input field shows the real-time, current value, of the channel, Units
Label is the displayed label for the channel's value (e.g. "Volts", "Amps", "C"),
User Name is the user's name for the channel (e.g. "Temp 1", "Pressure 2", etc),
and % Sample Rate is the speed, as a fraction of the Master Sample Rate, that the
channel is digitized (e.g. 50% would mean the channel is digitized at one-half the
sample rate specified in the master Setup dialog). The small display at the bottom
of the Probe dialog shows a plot of the current real-time value of the Channel.
• Click on the Units Label field and change "Volts" to "Amps". Click OK to exit
the Probe dialog.
The clicked on cell should be update to "Amps", as shown in figure 2.7.
Amps
Figure 2.7 Edited cell within the Network page
• Scroll through the Fields of the Network page using the horizontal scroll bar at
the base of the window.
Notice that the first 5 columns remain fixed, while the cells to the right of Column
#5 shift left and right with the horizontal scrollbar. You can scroll through, and
view, all Fields for all Channels in this manner. Figure 2.8 shows the Network
Page for Ch1 Vin+ after scrolling a little to the right.
Figure 2.8 Network Page scrolled horizontally to view the Ro & Rshunt Fields
2-17
Ch 2 instruNet Tutorial
• Scroll horizontally to the left edge so that "Value Input" is in Column #6 and
then scroll vertically until an input channels is no longer in the top row. For
example, in Figure 2.9, a Voltage Output channel is in the top row.
Notice that the title to Column #6 changed from Value Input to Value Output. This
is because the titles are optimized for the one channel in the top row.
Figure 2.9 Network Page scrolled vertically to view the title for voltage outputs.
• Vertically scroll to the top of the table and then click on the net cell of the first
row. (it should contain a 1) This will cause the Probe dialog to open and to
display the clicked on cell.
Channel
Addresses
The upper region of the Probe Dialog, shown in Figure 2.10, is used to select a
Channel's address (i.e. Network Number, Device Number, Module Number, and
Channel Number).
Figure 2.10 Network Address Configuration section of Probe Dialog
When instruNet World resets (e.g. powers on), the expansion slots in the
computer are scanned for instruNet controllers. Each controller found is given a
Network Number. For example, in Figure 2.10, instruNet World found a
controller in Slot 14 of a computer and designated the network connected to it as
Network #1. Hence the popup reads #1 Slot 14. This popup enables the user to
select any instruNet controller installed on the computer. There is a special
"Controller" in the popup that is labeled "Driver" (Network #0). This refers to the
instruNet Driver itself, and appears only once in the Network popup no matter
how many Controllers appear. The Driver contains fields that determine things
like the way displays show data in the Record page.
The Device popup menu lists the network Devices that are attached to the
Controller specified in the Network popup menu. When you select a Controller in
the Network popup, all devices attached to it appear in the Device popup. In the
figure shown to the left, only one network device is attached to the Controller in
Slot 14 and it appears as the second item in the popup. It is a Model 100 and is
designated Device #1 (1 #100). The Controller itself is a Device (Device #0) and
appears as the first item in the Device popup. The Controller contains Fields that
are specific to the controller, such as the network sample rate, or the value of a
digital output on the Controller's Digital I/O Connector.
2-18
Ch 2 instruNet Tutorial
The Module popup lists all Modules in the currently selected {Network, Device}.
Most Devices only have 1 module, as shown to the left.
The Channel popup lists all analog and digital I/O channels in the currently
selected {Network, Device, Module}. The illustration to the left shows 3
channels, 2 of which are voltage inputs, and the 3rd which is a voltage output.
• Explore your instruNet world via the 4 Channel Address popup menus at the
top of the Probe dialog, and the Settings popup menu. Press OK when you are
done exploring.
All instruNet Fields (i.e. all the cells in the Network page) are saved to disk and
Saving &
Loading Network loaded from disk with the press of a button. When a configuration is saved, all
information including items such as trigger conditions, sample rates and channel
Settings
units are stored. Waveform data is not stored at this time, but can be saved by
pressing the Save button in the Record page. When a configuration is loaded, all
items are restored to their previously saved condition. This means that instruNet
configurations for specific experiments only need to be set up once. And once a
configuration is loaded, it can be changed and then saved again if needed, possibly
in a different file.
• Select the Network page by clicking the Network tab.
The first two buttons at the top of the Network Page, Restore and Store, work as a
pair. Clicking the Store button saves the current network settings to a preferences
file within your operating system folder. Clicking Restore loads in this file. File
open and save dialogs do not appear, since the Fields are always saved to the same
file (i.e. a file with the same name). Obviously, you loose your last saved network
when you press the Restore button (careful !).
• Press the Store button to save your current Field settings to disk.
• Press the Clear button to erase your Field settings to their default values.
Notice how the "Amps" units label has now returned to its default setting of
"Volts".
• Press the Restore button to restore the previously saved settings.
Notice how the "Amps" units label has returned. To save the settings to the file of
your choosing, click the Save and Open buttons.
• Press the Save button . Type a file name and select a file location when the File
Save dialog appears. Remember where you put this file.
• Now press the Clear button to clear all settings to their default values.
• Press the Open button and select your saved file in the File Open dialog.
2-19
Ch 2 instruNet Tutorial
Notice how the "Amps" units label now appears. At this time, you have 2 files on
your hard disk with your saved network settings.
The Reset button differs from the Clear button in that it resets the hardware in
addition to clearing your fields. It has the same affect on an instruNet network as
restarting the computer. For example, Reset will reset clock in the controller,
whereas Clear will not.
Working with Sensors
Any voltage input channel can attach to any of the following
sensors: Voltage source, Current source, Resistance source,
Strain Gage, Load Cell, Accelerometer, Potentiometer, RTD,
or types J, K, T, E, R, S, B, and N Thermocouples. Sensors
can be wired in a variety of configurations including:
Differential Voltage Measurement (requires 2 voltage input
channels, e.g. Ch1 Vin+ and Chi Vin-), Single-ended Voltage
Measurement, Shunt Resistor, Voltage Divider, Bridge,
Quarter Bridge and for strain gages: Half-Bridge Bend, HalfBridge Axial, Full-Bridge Bend, Full-Bridge Axial I and FullBridge Axial II.
• Select the Network page by clicking on the Network tab.
• Click on the name of the voltage input channel with the attached signal source
(e.g. "Ch1 Vin+").
The Probe dialog will open with the address of the channel you clicked on
displayed in the Network Address. Additionally, the real-time value of the
channel, in Engineering Units (EU) will appear at the bottom of the display, as
shown in Figure 2.11.
Real-time plot of channel’s value
Actual reading in Engineering Units
Figure 2.11 The Snapshot Display
• Select Hardware in the Settings popup, as shown in Figure 2.12.
2-20
Ch 2 instruNet Tutorial
Figure 2.12 Hardware Settings Area
• Click on the Sensor popup to view the various Sensors that can directly be
attached to this channel, as shown to the right.
This popup tells instruNet which sensor is connected to your physical hardware
terminals (instruNet has no way of seeing what is out there). For more detailed
information on connecting sensors to instruNet, please refer to Chapter 3
Connecting to Sensors.
• Click on the Wiring popup and view the choices, as illustrated to the left.
The Vin+ - Vin- option is used for differential Voltage measurements to measure
the voltage between the Vin+ and Vin- terminals. The "common" signal on both
terminals is ignored, and therefore this technique can be used to reduce noise.
The Vin+ - Gnd option specifies Singled-Ended voltage measurement, which
measures the voltage between the voltage input terminal and the Ground terminal.
The latter 6 options (Q Bridge, Half Bridge Bend, Half Bridge Axial, Full Bridge
Bend, Full Bridge Axial I and Full Bridge Axial II are used to specify a wiring
options when working with a Strain Gage sensor. These wiring options are
described in more detail in Chapter 3.
• Click on the Range popup and view the options, as illustrated to the left. Select
the largest range (e.g. +- 5V).
This Field specifies the voltage input range. Accuracy is increased as the range is
reduced. For example, a +-80mV range might be accurate to +-45uV, whereas a
+-5V range might only be accurate to +-1.5mV. If you input a voltage in excess
of a bound, the bound is read. For example. If you apply 3V a voltage input with
a +-1.25V range, then +-1.25 will be read by the computer.
• Click in the Low Pass popup and view the options, as illustrated to the left.
The options that you see will depend on the connected hardware device. This
Field is used to select an analog filter at the front end of the voltage input
amplifier. Please consult Chapter 6, Hardware Reference to learn more about the
analog filter options for each hardware Device.
2-21
Ch 2 instruNet Tutorial
The Integrate field specifies how long, in Seconds, instruNet averages an input
signal before 1 number is returned to the user. This is often used to reduce high
frequency noise that has been added to a signal. The integration feature is
implemented by sampling the signal many times with the A/D converter, as fast as
it can, and then averaging the A/D values with software. The maximum allowable
integration time depends on the number of digitized channels and the sample rate.
For example, 2 channels could be sampled at 1000s/sec per channel and integrated
each for .5ms.
• Select Constants in the Settings popup, as illustrated in Figure 2.13.
Figure 2.13 Constants Settings Area
These Fields are used to specify constants that are used to calculate engineering
units when working with Resistance, Current, RTD, Load Cell, Accelerometer,
Potentiometer, and Strain Gage sensors. For example, Rshunt specifies the value
of the shunt resistor, in ohms, when doing a Resistance measurement. Please refer
to Chapter 3 for details on how to use these.
• Click OK in the Probe Dialog to return to the Network page.
• Enable the first three voltage input channels for digitizing by clicking once on
Column #5 of each channel, as illustrated in Figure 2.14.
Click here to enable digitizing
Figure 2.14 First 3 channels of Model 100 are enabled for digitizing.
• Select the Record page by clicking on the Record tab at the bottom of the
window.
• Click the Start button to begin recording.
2-22
Ch 2 instruNet Tutorial
The Record Page automatically creates a separate display for each recorded
channel, as shown in Figure 2.15. The actual signal that appears will depend on the
connected signal sources.
• Click the Stop button to Stop recording.
Figure 2.15 Three Channels in Record Page
Each display has a Channel Name box which appears to the right of the display,
as shown to the left and in figure 2.15. This box displays the channel name and
the real-time channel value in Engineering Units.
• Click on the Channel Name box of the top-most display to open the Probe dialog
at the Display settings area, as show in Figure 2.16.
Figure 2.16 Display Settings
• Change the Display Max Field to 2, change the Display Min Field to -2, and
click the lower-right Enter button.
These 2 Fields are used to set the top and bottom plot values of the vertical axis in
both the Record page display and the Probe dialog snapshot display. These
2-23
Ch 2 instruNet Tutorial
changes take affect when the Enter button is pressed, and can be viewed at the
bottom of the Probe Dialog, as shown in Figure 2.17. In many cases, one must edit
these values, depending on the Engineering Unit range of the digitized signal. For
example, one might set 0 and 100 for a temperature that ranges from 0 to 100C.
New top and bottom vertical axis bounds
Figure 2.17 Probe display with E.U.'s set to +/- 2V
• Press OK to exit the Probe dialog, and then press Start to begin recording.
Notice how the vertical axis scale change effects the appearance of the recorded
signal, as shown in Figure 2.18.
Figure 2.18 Record Page with top display Min/Max E.U. set to +/- 2V
Working With Calibration, Different Scales, & Mapping
instruNet supports Calibration and Converting to different scales (e.g. show psi
at sensor instead of Volts at screw terminals) with a 2 point mapping scheme.
All channels have a Mapping settings area that defines the relationship between
"internal units" and "external units". Internal units are the native units used by
instruNet, such as Volts. External units are what the user sees in the Record
page, the Network page, and the numbers returned by iNet(). External units are
linearly mapped to Internal units, and are therefore defined with 4 numbers,
that define 1 line ({x1,y1}, {x2,y2}), on an Internal Units Vs. External Units 2dimensional coordinate axis plane.
2-24
Ch 2 instruNet Tutorial
Sounds a little complicate? Imagine a linear temperature sensor that puts out
.1Volts when dipped in ice water (0°C) and 1Volts when dipped in boiling
water (100°C); and you want instruNet to display °C numbers in the Record
page and the Network page. To do this, one would set the Mapping fields to:
internal1: .1 (Volts)
external1: 0 (°C)
internal2: 1.0 (Volts)
external2: 100 (°C)
And set the Units Label field in the General Settings area to "C". The Units
Label does not effect instruNet numerically, yet is interpreted as random text
that is simply placed next numbers (i.e. it is a "label"). The Mapping fields;
however, effect numbers, yet not labels.
The Mapping numbers can also be used to implement calibration. Suppose a
thermocouple (i.e. temperature sensor) is attached to instruNet and is already
returning °C numbers (since that is the native units for the thermocouple), yet
you find there is a 2°C offset error in your sensor, and want instruNet to
"correct" for this error. To do this, the user would set up a mapping from
internal units to external units that reflected the offset error. e.g.
internal1: 100 (°C)
external1: 102 (°C)
internal2: 0.0 (°C)
external2: 2.0 (°C)
Notice that Mapping can be used to correct for an offset error by adding a
constant and can correct for a gain error by multiplying by a constant.
The Mapping setting area describes a line using two different methods: two
points "{x1,y1}, {x2,y2}", and "y = x*scale + offset". One can use either
method. For example, instead of setting the above 4 values, one could have set
the Offset field to 2.0, to show a 2°C Offset. When the Scale or Offset fields
are changed, the x1, y1, x2, y2 fields update automatically to reflect the new line
when the OK or Enter button is pressed.
Working with Digital Filters
All voltage input channels support digital lowpass, highpass, bandpass and
bandstop filters. The cut-off frequencies, minimum dB stopband attenuation (i.e.
filter order), maximum dB passband attenuation, and filter type (e.g. elliptic,
Chebyshev B, Chebyshev S, and Butterworth) can all be programmed separately
for each channel via the Lowpass, Highpass, Bandpass and Bandstop Settings
areas. In fact, these 4 models can be run at the same time (i.e. in serial) to
simultaneously do lowpass, bandpass, bandstop and highpass filtering on the same
channel. For example, one might only want to see frequencies between 20 and
1000Hz, except for the 55 to 65 band. This would involve a highpass filter at
20Hz, a bandstop filter between 55 and 65Hz, and a lowpass filter at 1000Hz.
2-25
Ch 2 instruNet Tutorial
• Select the Network page by clicking on the Network tab and then press the Reset
button to reset the network and all Fields.
• Click the channel name cell of the channel that is attached to your signal source
(e.g. Ch1 Vin+), and then select Lowpass in the Settings popup, as shown in
Figure 2.19.
Figure 2.19 Lowpass Filter settings area
The lowpass filter is illustrated in Figure 2.20. Notice that 4 numbers are
needed to describe the lowpass filter: minimum stop band attenuation (dB),
maximum pass band ripple (dB), pass band cut-off frequency (Hz) and stop
band cut-off frequency (Hz). And notice how these 4 numbers corresponds to
the StopB Attn, PassB Ripple, PassB F1 Hz, and StopB F1 Hz Fields in the
Lowpass Filter settings area.
• Turn the filter On by selecting Elliptic in the Filter popup (or any of the
other options other than Off).
• Enter a passband cut-off frequency value into the PassB F1 Hz field, a
stopband cut-off frequency into the StopB F1 Hz field, a minimum stop band
attenuation into the StopB Attn field, and a maximum pass band ripple into
the PassB Ripple field. Acceptable values would be {100, 150, 80, 1}. Press
the Enter key when done setting the values. If the filter is impossible to
design due to constraints of the specified values, an alert will appear with a
message coaching the user into selecting different parameters. In fact,
instruNet will not allow you to exit this dialog until the parameters are
acceptable, or the filter has been turned off by selecting Off in the Filter
popup.
2-26
Maximum Pass
Band ripple (dB)
(PassB Ripple)
Passband
Minimum Stop Band
attenuation (dB)
(StopB Attn)
Transition
Amplitude
Ch 2 instruNet Tutorial
PassB F1 (Hz)
Stopband
StopB F1 (Hz)
Frequency
Figure 2.20 Lowpass Filter Model
The filter order ranges from 1 to 32 in bandpass and bandstop filters, and from
1 to 16 in highpass and lowpass filters, depending on the supplied parameters.
As the filter becomes more demanding, the filter order increases, and the time
to run the filter also increases. In a typical case, it takes .1 to 2us per order per
point to run the filter. For example, on a Macintosh 840av (1993 technology) it
takes 2us per order per pt or 20us per point to implement a 10th order filter.
This would limit the maximum sample rate to 50Ksamples/second (i.e. 1 / 20e6 = 50e3).
• View the results of your filter by observing the effect it has on the waveform in
the Snapshot display. If you have a function generator connected, watch what
happens when you slowly change its frequency from 10Hz to 500Hz, for
example.
Figure 2.21 shows a 35 Hz signal applied to Ch1 Vin+, before and after the
implementation of a 30 Hz lowpass filter.
Figure 2.21 35 Hz Sine Wave before and after 30 Hz Lowpass Filter
Figures 2.19 through 2.21 show the filter models for the Highpass, Bandpass
and Bandstop filters.
2-27
Maximum Pass
Band ripple (dB)
(PassB Ripple)
Minimum Stop Band
attenuation (dB)
(StopB Attn)
Transition
Amplitude
Ch 2 instruNet Tutorial
Stopband
StopB F1 (Hz)
Passband
PassB F1 (Hz)
Frequency
Passband
Transition
Amplitude (DB)
Stopband
Transition
Figure 2.22 Highpass Filter Model
Stopband
Maximum Pass
Band ripple
(PassB Ripple)
Minimum Stop
Band attenuation
(StopB Attn)
StopB F1
PassB F2
PassB F1
StopB F2
Frequency (Hz)
Amplitude (DB)
2-28
Stopband
Transition
Passband
Transition
Figure 2.23 Bandpass Filter Model
Passband
Maximum Pass
Band ripple
(PassB Ripple)
Minimum Stop
Band attenuation
(StopB Attn)
PassB F1
StopB F2
StopB F1
PassB F2
Frequency (Hz)
Ch 2 instruNet Tutorial
Figure 2.24 Bandstop Filter Model
Table 2.1 shows which fields in the Settings area must be set for each filter model.
Edit field or
popup
Filter popup
PassB Ripple
StopB Attn.
PassB F1 Hz:
StopB F1 Hz:
StopB F2 Hz:
PassB F2 Hz:
Lowpass
Highpass
Bandpass
Bandstop
used
used
used
used
used
not used
not used
used
used
used
used
used
not used
not used
used
used
used
used
used
used
used
used
used
used
used
used
used
used
Table 2.1 Fields required for each Filter model
• Play with the different filter models and settings while viewing their effects in
the snapshot display. For example, to turn on a highpass filter, select Highpass
Filter in the Settings popup, select Elliptic in the Filter popup, and then set the
PassB F1 Hz, StopB F1 Hz, StopB Attn, and PassB Ripple fields as desires using
Figure 2.19 as a guide. Remember to press the Enter button to create the filter.
Working With Voltage Output Channels
Some hardware devices, such as the Model 100, provide Voltage Output channels.
In summary, these channels output the Voltage specified in the Value Output field
within the General settings area. Accuracy's are discussed in Ch6, Hardware
Reference. Voltage Output channels are named ChX Vout in the Network Page.
• In the Network page,
click on the 1st cell of
the first voltage output
channel. For the Model
100, this would be the
"Ch3 Vout" channel.
When the Probe dialog
opens, set the Value
Output field to 1, and
press the Enter button,
as illustrated to the
right.
The analog output channel is immediately updated to the new value when Enter is
clicked.
2-29
Ch 2 instruNet Tutorial
• Click OK to return to the Network page and view the Value Input column for the
chosen Voltage output channel. It should display a value in the vicinity of 1V.
With Voltage outputs, instruNet reads back the output voltage and displays this
value in the Value Out column. This is useful information when loading of the
output signal will change its value. An example of this is a bridge excitation circuit
where it is important to know the value of the excitation voltage within a small
margin (e.g. to ±.01%) yet the actual voltage only needs to be within several
percent of the target voltage.
Working With Digital I/O Channels
Some hardware Devices provide Digital I/O channels. For example, the Model 100
Device offers 8 bi-directional digital I/O bits where 8 different terminals physically
marked "DIO1..DIO8" can be set up independently as either a digital input or
digital output. With the Model 100 digital outputs, 0 to .8V is a logic 0, and 2V to
5V is a logic 1; however, with the Model 100 digital inputs, 0 to 1V is a logic 0,
and 3.2V to 5V is a logic 1. Also with these signals, voltages above 12V or below
-12V will result in physical damage (careful !). These 8 hardware bits are all
handled by 1 instruNet channel named "Ch25 Dio", where the 8bits are read from
or written to with a 1 byte word (i.e. 8 bits in a number between 0 and 255).
To set digital output bits, such as those on the Model 100, it is necessary to do the
following kinds of things:
• Click on the cell that contains the name of a Digital I/O Channel (e.g. "Ch25
Dio") and select Hardware in the Settings popup menu.
The Direction field specifies the bit direction, where a value of 1 specifies output,
and 0 specifies input. This field packs the 8bits into one 0 to 255 number, where
d0 corresponds to DIO1, d1 corresponds to DIO2, etc. For example, 410 =
000001002 would specify DIO3 as an output, and the rest of the hardware bits are
inputs. A Direction value of 010 = 000000002 specifies all hardware bits as inputs,
and a value of 25510 = 111111112 specifies all bits as outputs.
The Digital Out field is used to set the state of the bits that have been marked as
outputs by the Direction field. It does this with one 0 to 255 number where each
bit in the byte sets its corresponding hardware bit. For example, if 8 bits were set
up as outputs, then a Digital Out value of 1710 = 000100012 would set DIO1 and
DIO5 to a logic 1, and the rest to a logic 0.
The Value EU field in the General settings area is used to read the states of the 8
bits via a 0 to 255 number where each bit in the received byte corresponds to a
hardware bit. For example, reading 310 = 000000112 would mean that hardware
bits DIO1 and DIO2 are high, and the rest are low.
2-30
Ch 2 instruNet Tutorial
• Set the Digital Out
field to 110 =
000000012, set the
Direction field to 310 =
000000112 and click
the Enter button to
update the bits.
• Select General in the Setting popup menu and note the value displayed in the
Value EU field.
Value EU should show 25310 = 111111012. This is because the high 6 bits have
been set up as digital inputs in the Direction field, and if nothing is connected to
them, they will float high to a logic 1. DIO1 is set up as an output in the Direction
field, and has been set to a 1 in the Digital Out field, and is therefore read as a 1.
DIO2 has also been set up as an output in the Direction field, yet has been set to a 0
in the Digital Out field, and is therefore read as a 0.
Working With i200 Controller Digital Timer I/O Channels
The Model 200 (not 230) instruNet Controller boards have 10 digital input/output
channels, each of which can be operated in the following modes:
•
Digital Input: Read logic 1 (>2V) or logic 0 (<.8V) at input pin.
•
Digital Output: Set connector pin to logic 1 (>2V) or logic 0 (<.8V).
•
Clock Output: Output a continuous clock, or a fixed number of pulses
{1...2e9}. Set high time and period of clock. If period > 10ms, then we
generate clock with a 1ms timebase that drives two 0 to 32K timers; otherwise,
we use a .25us timebase. Periods must be >100us when fixing the # of pulses.
•
Pulse Counter: Read a 64bit counter that counts incoming >100us pulses since
reset.
•
Period Measurement: Measure the duration of 1 to 2e9 periods by counting a
.25us or 1ms timebase with a 64bit counter via the following options:
a) "Cycles" - aggregate number of periods to measure (between 1 and 255, or
multiple of 10 if between 256 and 2e9). e.g. 100 cycles of 10Hz yields
10sec. Minimum pulse duration is 100us when measuring < 10 periods;
and >10us otherwise.
b) "Measure" sum of entire cycle or just sum of high durations.
c) Count high "Resolution" 0.25us or lower resolution 1ms timebase.
d) "Modes":
2-31
Ch 2 instruNet Tutorial
o Wait & Continue: Wait till measurement completes, start another
measurement after read result.
o Wait & Reset: Wait till measurement completes, start another
measurement when next read.
o No Wait & Continue: Read 0 if not done, , start another measurement
after read result.
o No Wait & Reset: Read 0 if not done, start another measurement when
next read.
•
Frequency Measurement: Same as Period Measurement, except it returns the
frequency of the input signal after measuring the period for "Clk Period"
seconds. It checks to see if it passed the "Clk Period" second duration every
"Cycles" (1...255) input pulses. For example, if you set "Cycles" to 100, and
are measuring a ~10KHz signal, and set the "Clk Period" to 0.1sec, w/ a 0.25us
resolution, then it will count the 4MHz timebase w/ a 64bit counter (overflows
after 146,000 years). It will check to see if it passed the .1sec mark every 100
pulses (e.g. 10ms for 10KHz input). So it might stop after .11secs and see a
timebase count of ~440,000 for ~1100 cycles. It will then divide these 2
numbers and return to you a VERY accurate frequency measurement (e.g.
10,000.00). Notice that traditional frequency measurement devices count a
timebase for an specific duration, and error by the fraction of the input cycle
that has transpired since its last trigger edge. The minimum pulse duration is
100us when measuring < 10 periods; and >10us otherwise.
•
Quadrature Measurement: Returns the 4x position of a quadrature sensor with a
+/-32K counter. Connect wire A to Channel N, connect wire B to Channel
N+1, and program Channel N for Quadrature, and away you go. For details,
see Application Note #110.
Each counter/timer channel runs independently of the others, and of the other
channels on the network. For example, "Ch1 Timer" is the first channel in a
controller board. Its network address is Device 0, Module 1, Channel 1; and its
physical location is two pins on a 34 pin header connector located on the controller
board. The two connector pins are labeled "Ch1 Din" and "Ch1 Dout", one for
digital input and one for digital output. With the controller digital outputs, 0 to .8V
is a logic 0, and 2V to 5V is a logic 1; however, with the controller digital inputs, 0
to .8V is a logic 0, and 3.5V to 5V is a logic 1. Also with these signals, voltages
above 6V or below -6V will result in physical damage (careful !). An instruNet
Field is used to specify the function of Channel 1 as digital input, digital output,
clock output or period measurement. If digital input or period measurement are
chosen, the "Ch1 Din" pin is used; otherwise, the "Ch1 Dout" pin is used.
2-32
Ch 2 instruNet Tutorial
Figure 2.25 The Timer Settings Area
Physically, all controller channels are accessed at a 34 pin header connector (.025"
square pins with .1" spacing) located on the Controller board. This connector is
independent of the DB25 Connector that is used to cable to the network Devices.
One typically cables to this connector via a 34-wire ribbon cable that terminates
outside the computer at a screw terminal panel. Please refer to Chapter 1
Hardware Installation for details on cabling, and Chapter 6 Hardware Reference
for details on each pin within this connector.
• Select the Network page by clicking the Network tab, and then click in Column
#1 of the first controller's Ch 1 Timer channel (you might need to scroll down a
little). When the Probe dialog appears, select Timer in the Settings popup, as
illustrated in Figure 2.25.
The Function popup selects the channel's Function, as described below:
Digital Output The "ChX Dout" connector pin is set to a logic 0 (0-.8V) if the
Value I/O field in the General settings area is set to a 0; otherwise,
this pin is set to a logic 1 (2V-5V).
Digital Input
The Value I/O field in the General settings area is read as 0 if the
"ChX Din" connector pin is held by an external source below .8V
(otherwise, it floats to 5V). However, if this pin is above 3.5V, it
is read as a 1.
Clock Output
A square wave clock signal is driven out of the "ChX Dout"
connector pin where the cycle time is specified by the Clk Period
2-33
Ch 2 instruNet Tutorial
field, in units of seconds, and the high time is specified by the Clk
Out Hi field, in units of seconds.
Period
Measurement
The duration of the signal applied to the "ChX Din" connector pin
is measured and returned in the Value I/O field of the General
settings area, in Seconds units. If the Measure field is set to Cycle
time, the time is measured between consecutive falling edges;
otherwise the time is measured between a rising edge and the next
falling edge. The Meas Cycles field varies from 1 to 255 and sets
the number of cycles (or high times) that must occur over the
measured duration. For example, measuring 10 cycles of a 1KHz
square wave would return 10ms; whereas measuring 5 high times
of a 20KHz square wave would return 125us. If the Meas Resol
popup is set to .25us, the measurement is accurate to +/- .25us and
the falling-edge-to-falling-edge time (or rising-edge-to-fallingedge) must range from 3us to 16ms if Meas Cycles is 1, and 3us to
4.1sec if Meas Cycles > 1. Otherwise, if the Meas Resol popup is
set to 1ms, the measurement is accurate to +/- 1ms and the
falling-edge-to-falling-edge time (or rising-edge-to-falling-edge)
must range from 3ms to 32 secs if Meas Cycles is 1, and 3ms to
16Ksec if Meas Cycles > 1.
Table 2.2 shows which Fields are used for each of the different functions.
instruNet ignores settings not needed for a particular function. For example if
Digital Input or Digital Output is selected in the Function popup, instruNet ignores
all other Fields in the Timer area.
Field
Clk Period
Clk Out High
Measure
Meas. Resol.
Meas. Cycles
Digital In
not used
not used
not used
not used
not used
Digital Out
not used
not used
not used
not used
not used
Clock Out
used
used
not used
not used
not used
Period Meas.
not used
not used
used
used
used
Table 2.2 Fields used with different Controller Digital I/O Functions.
We will now set up one channel as a clock output and measure its duration with
another channel. This will require a 34 wire screw-terminal block cabled to the
digital connector on a Model 200 instruNet Controller board. If you do not have a
screw terminal block wired to your Controller, you can still do this experiment, yet
the measured period will not be correct.
• Connect a physical wire between Pin #6 (Ch1 Dout) and Pin #7 (Ch2 Din) of the
Controller Digital I/O connector.
2-34
Ch 2 instruNet Tutorial
• Set the Function popup to
Clock Out, the Clk Period
field to .005, and the Clk
Out Hi field to .001.
• Select General in the
Settings popup and set the
User Name field to
"Clock Out".
• Click the Enter button in
the bottom right of the
Probe Dialog to start the clock output.
• Select Ch2 Timer in the upper-right Channel popup to select the 2nd channel in
you instruNet Controller.
• Set the User Name field to "Clock Meas".
• Select Timer in the Settings popup.
• Set the Function popup to Period Meas, set the Resolution popup to .25µs, set
the Measure popup to Cycle Time, and set the Meas Cycles field to 1; as shown
in figure 2.25.
• Press OK to return to the Network page.
Notice how the names of your
first two Controller channels
have changed to "Clock Out"
and "Clock Meas", and how Clock Meas's Value field is displaying .005 seconds of
measured period. This is the period of the clock signal being output by Ch1 Timer
and being measured by Ch2 Timer. If you remove the wire connecting the Output
of Ch1 Timer and the input of Ch2 Timer, the Value field will change.
Figure 2.25 Timer Settings for Period Measurement
2-35
Ch 2 instruNet Tutorial
High speed >1Ks/sec/ch digitizing of analog signals by the instruNet Controller
ties up the i2x0 DSP processor, and therefore inhibits it from doing the
following during that time: pulse counter, output a specific number of clock
pulses, period measurement, and frequency measurement.
For more details on the counter timer features, please see Application Notes 96,
110, 181, 182,
Working With The Controller Time Since Reset Channel
The instruNet Controllers offer a channel that provides the time, accurate to .25us,
since the Controller was last reset. A reset occurs when instruNet is first used after
power up, the computer resets, and when the Reset button is pressed in the Network
page. This clock channel is called "Ch12 Time" and returns a number in units of
seconds that is derived from a 62bit counter that counts 4MHz.
• Select the Network page by clicking the Network tab, and scroll down until
you see the Controller's Ch12 Time channel. Notice how the Value cell
slowly increments at a 1 second rate.
2-36
Ch 2 instruNet Tutorial
Working With Multiple Controllers
instruNet supports multiple controllers (i.e. networks) in one computer. In this
case, the meaning of the "network number" becomes more important, since it
selects a particular network in the data tree from which to operate. To digitize
simultaneously from multiple controllers, one must select channels for digitizing in
the Network page (any channel combination across all controllers), and then press
the Start button in the Record page. There is one complexity however, which is
that each controller has its own Trigger settings. This is because each controller
operates independently (i.e. each has its own processor that manages its own data
acquisition task). To access a Trigger dialog for a specific network, press the
Trigger button in the Setup Dialog, and then select a specific network in the
Network popup menu.
Setting the Trigger with multiple controllers is a little tricky since one controller
cannot physically see the trigger signal attached to other controllers, and each
controller has no way of sending messages to its colleagues in a short period of
time. To make the digitizing from all networks trigger off the same signal, one
must attach the trigger signal to one channel from each network, and set up the
Trigger dialogs for each network to trigger off that one channel in each of their
respective networks.
Triggering Off
A Digital Input
To trigger off the instruNet 100 Ch25 Digital Input, specify this channel as the
trigger source, attach your trigger signal to Ch25 DIO8, and set the trigger
threshold to 200. When DIO8 is high (i.e. 2-5V), Ch25 is read as {128..255}; and
when DIO8 is held low (i.e. 0-.8V) Ch25 is read as {0-127}.
Next Step
This concludes the tutorial. From here you might consider exploring the following
areas: Chapter 3, Sensor Reference, which summarizes how to connect sensors;
Chapter 4, Programmers Tutorial, which is a tutorial designed to get programmers
up and running quickly.
2-37
Ch 2 instruNet Tutorial
2-38
Ch 3 Connecting to Sensors
Chapter 3, Connecting to
Sensors
This chapter describes how to connect sensors to instruNet hardware and how to
configure instruNet software for each type of sensor. instruNet allows different
sensors to be connected directly to each input channel including RTD's,
thermocouples, load cells, accelerometers, potentiometers, strain gages, resistance
sources, current sources; and single-ended and differential voltage sources. In
some cases, the user must add an external resistor to facilitate the reading of a
sensor. instruNet supports a direct connection, returning native engineering units,
to the following sensors:
Sensor
Voltage
Voltage
Voltage
Current
Resistance
Resistance
Strain Gage
Strain Gage
Strain Gage
Strain Gage
Strain Gage
Strain Gage
Strain Gage
RTD
RTD
Units
Volts
Volts
V/V
Amps
Ohms
Ohms
Strain
Strain
Strain
Strain
Strain
Strain
Strain
Celsius
Celsius
J, K, T, E, R, S, B, & Celsius
Wiring
single-ended
differential
bridge
shunt resistor
voltage divider
bridge
voltage divider
Q bridge
H bridge bend
H bridge axial
F bridge bend
F bridge axial I
F bridge axial II
voltage divider
bridge
differential
Thermistor
Load Cell
Accelerometer
Potentiometer
Quadrature Sensor
voltage divider
bridge
N Thermocouple
Celsius
Kg, LBs
G
0 to 1
Counts
Constants
None (measure voltage between Vin & Gnd)
none (measure voltage between Vin+ & Vin-)
Vinit, Vout (measure ratio of Vout/Vin)
Rshunt
Rshunt, Vout
Ro, Rshunt, Vout
Ro,Shunt, Vout, Vinit, GF
Ro, Vout, Vinit, GF, Rlead
Ro, Vout, Vinit, GF, Rlead
Ro, Vout, Vinit, GF, Rlead, v_Poisson
Vout, Vinit, GF
Vout, Vinit, GF, v_Poisson
Vout, Vinit, GF, v_Poisson
alpha, delta, Ro, Shunt, Vout
alpha, delta, Vout, Vinit, Ro
none
Ro, Rshunt, Vexe, Vinit, alpha, delta, GF, v_Poisson
Ro, Vexe, Vinit, GF
single-endeded or diff.
Vinit, GF
bridge
Ro, Vexe, Vinit
Please see Application Note #110
Figure #
3-1
3-2
3-2b
3-3
3-4
3-5
3-6
3-7
3-8
3-9
3-10
3-11
3-12
3-13
3-14
3-15
3-16
3-17
3-18
3-19
Table 3.1, Sensors that can directly be connected to instruNet
3-1
Ch 3 Connecting to Sensors
Connecting a Sensor Directly to instruNet
The instruNet voltage input terminals (often labeled "Vin(+)" or "Vin(-)") can
directly connect to a variety of sensors, with instruNet software returning values in
native engineering units (e.g. degrees Celsius, strain, Volts, Amps, ohms). This
requires wiring the sensor to the instruNet hardware in the appropriate manner, and
then configuring the instruNet software for your particular sensor, as described in
the following steps:
1) Physically Wire your Sensor to instruNet hardware
The first step is to physically wire your sensor to the instruNet hardware, per the
Hardware Reference guidelines at the end of this chapter. Each sensor listed in the
previous table is discussed in detail in this reference. For example, to connect a J
Thermocouple, one would attach the positive lead of the thermocouple to the
instruNet Vin+ terminal, and the negative lead to the Vin- terminal. The input
terminals are protected against over voltage and electrostatic discharge, therefore it
is not always necessary to power off network devices (e.g. Model 100) while
wiring sensors, although turning power off is recommended as a good safety
practice. If your sensor does not fit into one of the standard categories in the
previous table, then you need to choose the closest category, and then do the
calculations necessary to resolve your desired engineering units. If you do power
OFF your network, please use the following sequence:
1.
2.
3.
4.
5.
Power OFF powered devices connected to the Network
Power OFF Computer
Configure network cables, sensors, and devices
Power ON Computer
Power ON powered devices connected to the Network
2) Tell the instruNet software which Sensor is connected
Set the Sensor popup in the Hardware settings area of the Probe dialog to the
correct Sensor (e.g. Volts, J Thermocouple, etc). The sensors to choose from are
listed in the first column of the Sensor Hook-up Table, at the beginning of this
chapter.
3-2
Ch 3 Connecting to Sensors
To set the Sensor popup, one would:
1. Open the instruNet World window by launching the Windows "instruNet
World Win32.exe" or Macintosh "instruNet World Mac" application
program (e.g. double-click on its icon).
2. Click on the Network tab at the bottom of the window to select the network
page.
3. Click on the name of your channel in the left-most column to open the
Probe dialog.
4. Select Hardware in the Settings popup menu.
5. Select the desired sensor in the Sensor popup menu, as illustrated in the
previous figure.
3) Tell the instruNet software how the Sensor is wired
Set the Wiring popup in the Hardware settings area of the Probe dialog to the
correct Wiring (e.g. Single-Ended, Differential, Bridge, Voltage Divider, etc).
Please consult the Sensor Hook-up Table, at the beginning of this chapter, for
guidance. Recall that the chosen wiring popup must match your actual physical
hardware wiring.
4) Set the appropriate constants as required
3-3
Ch 3 Connecting to Sensors
R unknown
R shunt
Set the fields in the Constants settings area as
needed. This involves selecting Constants in the
V
Setting popup, and then setting specific Constants
out
fields as noted in the previous table. For details on
V in
specific sensors, please consult the Sensor
V +
Reference at the end of this chapter. For example,
in
to measure a resistance instruNet needs to know the
Gnd
value of an external shunt resistor "Rshunt", in
ohms, and the value of the excitation voltage
"Vout", in volts, as illustrated to the right. This
would involve setting the Rshunt and Vout Constants fields to correspond to your
actual wiring. instruNet software would then automatically return an amplitude in
"ohms" units after measuring the voltage at the Vout terminal, measuring the
voltage between the Vin+ and Vin- terminals, and calculating the realtime
Runknown.
5) Select the appropriate input voltage range
Set the Range popup in the Hardware Settings area as needed. This selects a
voltage range that is used by instruNet. If the voltage exceeds a bound, then the
bound is returned by the software. For example, if you input 2V and the range is
+/- 1V then instruNet will return 1Volt. The resolution and accuracy of the
measured signal increases when the range is reduced. For example, with the Model
100, the voltage accuracy is 15uV in the +/-10mV range, and 1.5mV in the +/- 5V
range with 1ms of integration. Some sensors require a specific voltage range, or
only allow one range. For example, the range with thermocouples is always in the
neighborhood of +/- 100mV.
6) Set the Integrate popup
Set the Integrate popup in the Hardware Settings area as needed. This selects the
duration that the signal is averaged before instruNet returns one number. For
example, if you choose 16.666ms (one 60Hz line cycle), it will return the average
signal value over a period of 16.666ms. This is helpful at reducing noise for
signals acquired at slow sample rates (e.g. to integrate 16ms worth of data the
sample rate must be greater than 16ms per point, or slower that 60samples/second).
Each hardware device offer different Integrate options.
7) Select the appropriate Analog Filter
Set the analog Low Pass filter popup in the Hardware Settings area as needed (e.g.
off, 40Hz, 4KHz). Each hardware device offers different analog low pass filter
options as described in Ch 8, Hardware Reference (not all devices support
hardware analog filtering). Low pass filters cause high frequencies to be rejected,
while low frequencies are passed. Visually, the signal becomes "smoother". To
see the effects of various filters, view the digitized signal at the bottom of the probe
dialog, after making different selections (you might not be able to do this until you
are further along in the set up process).
8) Set your Digital filters as needed
If you need to do a digital low pass, high pass, band pass, or band stop filter on
your digitized waveform, please set the fields in the filter Settings areas (e.g. Low
3-4
Ch 3 Connecting to Sensors
Pass, High Pass) as desired. Digital filters are run on the waveform post
acquisition, and only effect digitized waveforms (not single values read by
instruNet). Please refer to Ch2 Tutorial, Setting Digital Filters for an expanded
discussion of this powerful feature.
9) Consult the Sensor Reference for specifics
Carefully implement the Sensor Reference instructions for your particular sensor,
later in this chapter, and read the corresponding footnotes at the end of this chapter.
Different sensors require different range, filter, and constants settings; and care
should be taken to insure accurate results.
10) Check your Work
To check your work, view the incoming signal, in realtime, at the bottom of the
Probe dialog.
This display shows the sensor's value, in realtime, in native engineering units (e.g.
Volts, Amps, degrees Celsius, strain) based on your software settings and external
hardware wiring. The numerical value displayed at the bottom right is the actual
real time value being read by instruNet. The plot shows the digitized version of
your sensor value vs. time. The horizontal scale of this display is determined by
the Pts Per Scan, No. of Scans, Scan Mode, Horiz Scale, and Sample Rate fields
within the global Setup dialog (i.e. press the Record tab at the bottom of the
instruNet World window, and then press the Setup button at the top). For details
on how these work, please consult "Ch2, Working with the Voltage Inputs". To
adjust the vertical scale of the probe display, select Display in the Setting popup,
and then set the Display Max and Display Min fields to the desired engineering
units values that correspond to the top and bottom of the display (e.g. set 1 and -1
to view a signal that varies from -1V to 1V). Press the Enter button to cause the
new settings to take effect, and then view the updated display.
11) If your Sensor is not working, Fix it !
Listed below are several debugging hints for channels that are returning "bad"
results:
a. Check that you have the correct channel
To check that you have the correct channel, and that it is being digitized by the
software, view the probe dialog display as you disconnect one wire from your
sensor. The value printed in the dialog lower right corner should change, to
indicate that your displayed value is in some way connected to that wire. Also,
if you touch the input terminal with your finger, you should notice some slight
variation since your body acts as an antenna and causes radio stations, and
such, to drive the input terminal (due to its high input impedance).
3-5
Ch 3 Connecting to Sensors
b. Check that instruNet is correctly measuring the voltage
At any time, you can set the Sensor popup to Volts, and set the Wiring popup to
Vin+ - Vin- to cause instruNet to measure the voltage between the Vin+ and
Vin- terminals. The measured voltage appears in the Probe dialog lower right.
You can then check this against a volt meter that is placed in parallel between
the Vin+ and Vin- terminals. Remember to set the Range popup if your signal
is "clipping" on a bound. To measure the voltage between your Vin screw
terminal (Vin+ or Vin-) and ground, you would do the same thing, yet select
Vin - Gnd in the Wiring popup.
c. Check the engineering units calculations
If your voltage looks good, yet the returned engineering units value looks bad,
then pull out a calculator (or better yet, a spreadsheet) and run your constants
and known values into the equations listed in the Sensor Reference to check the
processing of these numbers. Perhaps one of the fields in the Constants settings
area is not set correctly.
d. Make sure you do not exceed the maximum input voltage
Make sure you are not exceeding the maximum input voltage, with respect to
the Gnd terminal, as specified in "Ch8 Hardware Reference". To check this,
measure the voltage between the Vin+ (or Vin-) terminal and the Gnd terminal
with a Volt Meter. For example, in the Model 100, this voltage must not be
less than -5V or greater than +5V. Exceeding a maximum typically does not
cause damage unless it is very large (e.g. greater than +/- 20V).
e. Check your ground connections
If the ground between the instruNet device and your signal source is unstable,
then connecting a wire between the instruNet Gnd terminal, and your signal
source ground might help (e.g. attach a wire, or 1Kohm resistor, between the
GND and Vin(-) terminals). Alternatively, if the instruNet Gnd is tied to the
ground of your signal source, and these are at different voltages with respect to
Earth ground, then current will flow between them. This current will cause
voltage drops and subsequently may induce weird effects -- breaking this
ground connection might help. The best way to determine what helps is to try
different things (e.g. hold a wire between two grounds) and observe what
happens in the display at the bottom of the Probe dialog.
g. Recheck your work
Recheck your hardware wiring and software settings.
12) Save your work.
To save the current configuration of instruNet (i.e. the settings displayed in the
Network page and accessed via the Probe dialog), press the Network tab at the
bottom of the window to select the Network page, and then press the Save button at
the top of the window to save the settings to disk. A file save dialog appears, and it
is here that you must specify a file name and file location (remember where you
put it).
3-6
Ch 3 Connecting to Sensors
To check your saved settings: exit instruNet world, re-enter instruNet (e.g. launch
Windows "instruNet World Win32.exe" or Macintosh "instruNet World
Mac"), press the Network tab at the bottom of the window to select the Network
page, press the Open button at the top of the window, select your saved settings file
(this will load your save settings), click on the channel that you just set up, and
then view the realtime display at the bottom of the Probe dialog.
Alternatively, one could press the Store button to save the settings directly to a
preferences file in the operating system folder, and then press the Restore button, at
a later date, to restore them. The advantage of Save/Restore is the user does not
need to specify a file name or file location; whereas the disadvantage is the saved
file is overwritten the next time someone presses Store.
Sensor Reference
instruNet connects directly to a variety of sensors and returns engineering units, as
summarized in the following pages. Each sensor must be wired exactly as shown
in the following figures, and the software must be configured exactly as described
in the adjacent instructions.
Single-ended
Voltage
Measurement
Single-Ended Voltage measurement involves
Vout
reading a voltage between the Vin+ (or Vin-)
_
+
+
Vin
instruNet input terminal and the Gnd input
Voltage Voltage
+
terminal, as illustrated in the figure to the
Source
Source
Vin
right. The Gnd terminal is typically tied to
_
_
Gnd
earth ground through the user's cable, the
instruNet network cable, or an external power
Fig 3.1 - Singled-Ended
supply cable. Most amplifiers that supply a
Voltage
Measurement Mode
single-ended output signal have their grounds
with Two Signal Sources.
tied to earth ground via the power supply
cable. instruNet channels, configured for
"Voltage" measurement, return a value in
units of Volts.
The Vin+ and the Vin- screw terminals function identically when used to read
single-ended voltages (e.g. Ch1 corresponds to Vin+, and Ch2 corresponds to Vinon the Model 100).
To do a Single-Ended Voltage measurement you must:
1. Set the Sensor field in the Hardware settings area to Voltage.
2. Set the Wiring field in the Hardware settings area to Vin - GND.
3. Wire your voltage source per figure 3.1, and refer to the steps at the beginning
of this chapter for more information on how to set up your sensor.
4. For information on measuring voltages in excess of +-5V, please see
Application Note #82 Measuring Large Voltages.
3-7
Ch 3 Connecting to Sensors
Differential
Voltage
Measurement
Differential Voltage measurement involves reading a
Vout
_
voltage between a pair of instruNet Vin+ and Vin_
Vin
input terminals, as illustrated in the figure to the
Voltage
Source
right. The Gnd terminal is not used when connecting Vin+
a differential voltage source to instruNet; however,
+
Gnd
you must be careful to insure that the voltage applied
to the Vin+ or Vin- terminal does not exceed the
Fig 3.2 - Differential
maximums specified in "Ch8 Hardware Reference"
Voltage Measurement
(e.g. all Vin terminals on the Model 100 must be
with One Signal Source.
kept between -5V and +5V, with respect to the Gnd
terminal, in order to assure accurate readings).
Differential mode is preferable for applications
involving significant
amounts of low frequency (< 5kHz) common mode noise that might result from
long signal cables. instruNet channels, configured for "Voltage" measurement,
return a value in units of Volts.
To do a Differential Voltage measurement you must:
1. Set the Sensor field in the Hardware settings area to Voltage.
2. Set the Wiring field in the Hardware settings area to Vin+ - Vin-.
3. Wire your voltage source per figure 3.2, and refer to the steps at the beginning
of this chapter for more information on how to set up your sensor.
4. If your measured signal is noisy, try connecting a wire (or 1Kohm resistor)
between the Vin- and GND terminals (to reduce common mode noise), and
refer to footnote #5 at the end of this chapter for details on how to low pass
filter the measured signal.
5. For information on measuring voltages in excess of +-5V, please see
Application Note #82 Measuring Large Voltages.
Bridge Ratio
Voltage
Measurement
3-8
Bridge Ratio Voltage measurement
Vout
+ε
involves measuring the ratio of the
-ε
Vinvoltage measured across a device (e.g.
a bridge) to the excitation voltage
Vin+
applied to the device, as illustrated in
the figure to the right. This involves
+ε
-ε
Gnd
applying a voltage across the device
and measuring the voltage across the
two intermediate nodes via a pair of
Fig 3.2b- Bridge Ratio
instruNet Vin+ and Vin- input
Voltage Measurement
terminals. The excitation voltage for
the bridge is supplied by either the
instruNet Vout terminal or by
an external voltage source. instruNet
calculates the ratio, returning "V/V" engineering units, using the equations:
Ch 3 Connecting to Sensors
Vratio (V/V) = ((Vin+ - Vin-) - Vinit) / Vout
Vinit and Vout are fixed values that are specified by the user in the Constants
Settings area, whereas (Vin+ - Vin-) are measured in realtime by instruNet. For
more details, please see Application Notes #14 Strain Gages, #75 Load Cells, and
#139 Ratio Measurements.
To do Voltage ratio measurement you must:
1. Set the Sensor field in the Hardware settings area to Voltage.
2. Set the Wiring field in the Hardware settings area to Bridge .
3. Set the Ro field in the Constants settings area to the value of one Ro bridge
resistor (i.e. or approx resistance across the device), in ohms units.1,3
4. Set the Vout field in the Constants settings area to specify an excitation voltage
to be applied to the bridge. If you are applying an external excitation voltage,
enter -Ro value in the Ro edit field (e.g. -100 instead of 100ohms) to tell the
software that the excitation is external, and then enter the external excitation
voltage in the Vout.2 In high current cases (e.g. >2mA), it is often helpful to
alternate the polarity of the excitation voltages to evenly burden the +/-12V
supplies.11
5. Set the Vinit field in the Constants settings area to the voltage measured when
the bridge is not stimulated, in Volts units (to null the bridge).8
6. Wire your voltage source per figure 3.2b, and refer to the steps at the beginning
of this chapter for more information on how to set up your sensor.5,10
7. To eliminate susceptibility to RFI noise, it may be necessary to place a
capacitor between the Vin+ and Vin- screw terminals, and between the Vinand Gnd screw terminals, as noted in Application #14 Strain Gages. Typical
values are .01uF.
Current measurement involves reading the
voltage across an external user supplied shunt
resistor, to which a current source is
connected, as illustrated to the right. The
voltage is measured between a pair of
instruNet Vin+ and Vin- input terminals.
instruNet then calculates the current through
the shunt resistor using the following
equation, and returns a value in "Amps"
units:
V
out
V in
V +
in
_
R shunt
Current
Measurement
Current
Source
i
+
Gnd
i
Fig 3.3 - Current Measurement.
current (Amps) = (Vin+ - Vin-) / Rshunt
Shunt resistor values are typically chosen to cause a large voltage (several volts
maximum) to be measured by instruNet, without saturating the current source (i.e.
exceeding its maximum output voltage), and without heating up the resistor
significantly to cause its resistance to change. If the Rshunt value is low, then the
3-9
Ch 3 Connecting to Sensors
voltage across it is low, and this decreases the signal to noise ratio of the measured
signal. Also, Rshunt must be selected such that the voltage across it does not
exceed the instruNet maximum input voltage (e.g. +/-5V with the Model 100).
Due to these limitations, instruNet might not let you set some of the fields too high
or too low.
To do a Current measurement you must:
Resistance measurement using a voltage
divider involves connecting a resistor of
unknown value in series with an external user
supplied shunt resistor of known value,
applying a voltage across the divider circuit,
and measuring the voltage across Runknown,
as illustrated to the right. The voltage across
Runknown is measured between a pair of
instruNet Vin+ and Vin- input terminals
while the excitation voltage is supplied by the
instruNet Vout terminal. instruNet then
calculates the value of Runknown using the
following equation, and returns a value in
"ohms" units:
V
out
V in
V +
in
Gnd
R unknown
Resistance
Measurement:
Voltage Divider
Circuit
R shunt
1. Set the Sensor field in the Hardware settings area to Current.
2. Set the Wiring field in the Hardware settings area to Shunt Resistor .
3. Set the Rshunt field in the Constants settings area to the value of your external
user supplied Rshunt resistor, in ohms units.1,3
4. Set the Voltage Range field in the Hardware settings area to something similar
to the maximum expected current * Rshunt.
5. Wire your current source per figure 3.3, and refer to the steps at the beginning
of this chapter for more information on how to set up your sensor.
6. If your measured signal is noisy refer to footnote #5 at the end of this chapter
for details on how to low pass filter the measured signal; also, if your current
source is fully isolated from GND, connecting a 1K ohm (or wire) between the
Vin- and GND terminals might reduce common mode noise.
8. For more details, please see Application Note #82 Measuring Large Currents.
Fig 3.4 - Resistance Measurement
- Voltage Divider Method
Runknown (Ohms) = Rshunt * (Vin+ - Vin-) / ((Vin+ - Vin-) - Vout)
To do a Resistance measurement using a Voltage Divider, you must:
1. Set the Sensor field in the Hardware settings area to Resistance.
2. Set the Wiring field in the Hardware settings area to Voltage Divider .
3. Set the Rshunt field in the Constants settings area to the value of your external
user supplied Rshunt resistor, in ohms units.1,3,6
3-10
Ch 3 Connecting to Sensors
4. Set the Vout field in the Constants settings area to specify the excitation
voltage that is to be applied to the divider. In high current cases (e.g. >2mA), it
is often helpful to alternate the polarity of the excitation voltages to evenly
burden the +/-12V supplies.11
5. Set the Voltage Range field in the Hardware settings area to something similar
to Vout * (Runknown_Maximum / (Runknown_Maximum + Rshunt)).
6. Wire your voltage source per figure 3.4, and refer to the steps at the beginning
of this chapter for more information on how to set up your sensor.10
Resistance
Measurement:
Bridge Circuit
R
Resistance measurement using a bridge
V
un
out
circuit involves connecting a resistor of
Ro
kn
ow
V unknown value as one leg of a full-bridge
n
in
circuit, applying a voltage across the bridge,
V +
and measuring the voltage across the two
in
Ro
intermediate nodes. The intermediate node
Ro
Gnd
voltage is measured between a pair of
instruNet Vin+ and Vin- input terminals
Fig 3.5 - Resistance
while the bridge excitation voltage is supplied
Measurement
- Bridge Circuit
by either the instruNet Vout terminal or an
external voltage source. In figure 3.5,
Runknown is a resistor whose value is being
measured and Ro is a
similar valued resistor of known value4. This technique is only accurate if
Runknown stays in the range of Ro, +/- 50%. If you need to measure a resistance
with more range, please use the Resistance Measurement using a Voltage Divider,
described earlier. instruNet calculates the value of Runknown using the following
equation, and returns a value in "ohms" units:
Runknown (ohms) = Ro * (Vout - 2.0 * (Vin+ - Vin-)) / (Vout + 2.0*(Vin+ - Vin-))
To do a Resistance measurement using a Bridge circuit you must:
1. Set the Sensor field in the Hardware settings area to Resistance.
2. Set the Wiring field in the Hardware settings area to Bridge .
3. Set the Ro field in the Constants settings area to the value of one Ro bridge
completion resistor, in ohms units.1,3,4
4. Set the Vout field in the Constants settings area to specify an excitation voltage
to be applied to the bridge. If you are applying an external excitation voltage,
enter -Ro value in the Ro edit field (e.g. -100 instead of 100ohms) to tell the
software that the excitation is external, and then enter the external excitation
voltage in the Vout. In high current cases (e.g. >2mA), it is often helpful to
alternate the polarity of the excitation voltages to evenly burden the +/-12V
supplies.11
5. Wire your voltage source per figure 3.5, and refer to the steps at the beginning
of this chapter for more information on how to set up your sensor.5,10
3-11
Strain measurement using a voltage divider
circuit involves connecting a strain gage in
series with a shunt resistor of known value,
applying a voltage across the pair and
measuring the voltage across the strain gage,
as illustrated to the right. The voltage across
the strain gage is measured between a pair of
instruNet Vin+ and Vin- input terminals
while the excitation voltage for the divider is
supplied by the instruNet Vout terminal.
instruNet calculates the value of the strain
using the following equations, and returns
"strain" engineering units.
V
out
V in
V +
in
Gnd
R gage
Strain Gage
Measurement:
Voltage Divider
Circuit
R shunt
Ch 3 Connecting to Sensors
Fig 3.6- Strain Gage Measurement
- Voltage Divider Circuit
Rgage (Ohms) = Rshunt * (Vin+ - Vin-) / (Vout - (Vin+ - Vin-))
Strain = ((1 / (GF * Ro)) * (Rgage - Ro))
Ro is the resistance of the unstrained strain gage and Rgage is the resistance of the
gage when strained. Voltage divider circuits are less accurate than bridge circuits
when measuring small resistance changes (which are typical in strain gage
measurements), but are easier and less expensive to build. For strain gage
measurements, a bridge circuit is highly recommended over a voltage divider.
To do a strain gage measurement using a Voltage Divider, you must:
1. Set the Sensor field in the Hardware settings area to Strain Gage.
2. Set the Wiring field in the Hardware settings area to Voltage Divider .
3. Set the Voltage Range field in the Hardware settings area to something similar
to Vout * (Ro / (Rshunt + Ro)).
4. Set the Rshunt field in the Constants settings area to the value of your external
user supplied Rshunt resistor, in ohms units.1,3,6
5. Set the Ro field in the Constants settings area to the value of your gage when
unstrained, in ohms units.
6. Set the GF field in the Constants settings area to the gage's gage factor.9
7. Set the Vout field in the Constants settings area to specify the excitation
voltage that is to be applied to the divider.6 In high current cases (e.g. >2mA),
it is often helpful to alternate the polarity of the excitation voltages to evenly
burden the +/-12V supplies.11
8. Wire your strain gage per figure 3.6, and refer to the steps at the beginning of
this chapter for more information on how to set up your sensor.5,10
3-12
Ch 3 Connecting to Sensors
R shunt
Strain measurement using
R L Gage Cable
V
a 1/4 bridge circuit
out
Ro
involves wiring a strain
current
V gage as one leg of a fullin
C
bridge circuit, applying a
Ro
V +
RL
in
C
voltage across the bridge,
Ro
and measuring the voltage Gnd
sense R L
across the two
Shield
intermediate bridge nodes
Fig
3.7
Strain
Measurement
via a pair of instruNet
Quarter Bridge Circuit
Vin+ and Vin- input
terminals. The excitation
voltage for the bridge is supplied by either the instruNet Vout terminal or by an
external voltage source. In figure 3.7, Rgage is a strain gage, Ro is either a fixed
resistor of known value or a fixed unstrained strain gage of value Ro, and RL is the
lead wire resistance. instruNet calculates the value of the strain, returning "strain"
engineering units, using the equations:
R gage
Strain Gage
Measurement Quarter Bridge
Vratio (V/V) = ((Vin+ - Vin-) - Vinit) / Vout
Strain = (-4Vratio / [GF * (1 + 2Vratio)]) * (1 + RL /Ro )
Ro, RL, GF, Vinit and Vout are fixed values that are specified by the user in the
Constants Settings area, whereas (Vin+ - Vin-) are measured in realtime by
instruNet. Ro and Unstrained-Rgage must be the same value (e.g. 350ohms) in
order for the bridge to operate properly.4 For more details, please see Application
Notes #14 Strain Gages, #75 Load Cells, and #139 Ratio Measurements.
To do Strain Gage measurement using a 1/4 Bridge circuit you must:
1. Set the Sensor field in the Hardware settings area to Strain Gage.
2. Set the Range field in the Hardware settings area to +/- 10mV.7
3. Set the Ro field in the Constants settings area to the value of one Ro bridge
completion resistor, in ohms units .3,4
4. Set the GF field in the Constants settings area to the gage's gage factor.9
5. Set the Vout field in the Constants settings area to specify the voltage that is to
be applied to the bridge (1V is typical). If you are applying an external
excitation voltage, enter -Ro value in the Ro edit field (e.g. -100 instead of 100
ohms) to tell the software that the excitation is external, and then enter the
value of the external excitation voltage into the Vout field (e.g. 4V).2 In high
current cases (e.g. >2mA), it is often helpful to alternate the polarity of the
excitation voltages to evenly burden the +/-12V supplies.11
6. Set the delta, Rlead field in the Constants settings area to the resistance, in
ohms, of the wires leading to the bridge (0 ohms is typically ok).
7. Set the Vinit field in the Constants settings area to the voltage measured when
the bridge is unstrained, in Volts units.8
8. Set the Wiring field in the Hardware settings area to Q Bridge.
3-13
Ch 3 Connecting to Sensors
9. Capacitors across the voltage input terminals are highly recommended for
reducing errors caused by RFI. With 350ohm gages, 0.1uF caps create a low
pass filter at 4KHz [4K = 1 / (6.28 * 350 * 0.1e-6)], and are ideal at minimizing
RFI effects.
10. Wire your voltage source per figure 3.7, and refer to the steps at the beginning
of this chapter for more information on how to set up your sensor.5,10
RL
Measuring bending strain using a 1/2
bridge configuration involves wiring
Ro
V
two strain gages as shown in figure
out
3.8, applying a voltage across the
V bridge, and measuring the voltage
in
across the two intermediate bridge
Ro
V +
nodes via a pair of instruNet Vin+
RL
in
and Vin- input terminals. The
Gnd
excitation voltage for the bridge is
supplied by either the instruNet Vout
Fig 3.8 - Strain Measurement - Half
terminal or by an external voltage
Bridge Circuit
source. In figure 3.8, Rgage is a
strain gage, Ro is either a fixed
resistor of known value or a fixed
unstrained strain gage of
value Ro, and RL is the lead wire resistance. instruNet calculates the value of the
strain, returning "strain" engineering units, using the equations:
R gage (-ε) R gage (+ε)
Strain Gage
Measurement Half Bridge
(Bending)
Vratio (V/V) = ((Vin+ - Vin-) - Vinit) / Vout
Strain = (-2Vratio / GF) * (1 + RL /Ro )
Ro, RL, GF, Vinit and Vout are fixed values that are specified by the user in the
Constants Settings area, whereas (Vin+ - Vin-) are measured in realtime by
instruNet. Ro and Unstrained-Rgage must be the same value (e.g. 350ohms) in
order for the bridge to operate properly4.
To do a bending Strain Gage measurement using a 1/2 Bridge circuit you must:
1. Do steps #1 through #7 listed in the previous "Strain Gage Measurement Quarter Bridge" discussion.
2. Set the Wiring field in the Hardware settings area to H Bridge Bend .
3. Wire your voltage source per figure 3.8, and refer to the steps at the beginning
of this chapter for more information on how to set up your sensor.5,10
3-14
Ch 3 Connecting to Sensors
RL
Measuring axial strain using a 1/2
bridge configuration involves wiring
Ro
V
two strain gages as shown in figure
out
3.9, applying a voltage across the
V bridge, and measuring the voltage
in
across the two intermediate bridge
Ro
V +
nodes via a pair of instruNet Vin+
RL
in
and Vin- input terminals. The
Gnd
excitation voltage for the bridge is
supplied by either the instruNet Vout
Fig 3.9 - Strain Measurement terminal or by an external voltage
Half Bridge Circuit (Axial)
source. In figure 3.9, Rgage is a
strain gage, Ro is either a fixed
resistor of known value
or a fixed unstrained strain gage of value Ro, and RL is the lead wire resistance.
instruNet calculates the value of the strain, returning "strain" engineering units,
using the equations:
R gage (-ε) R gage (+ε)
Strain Gage
Measurement Half Bridge
(Axial)
Vratio (V/V) = ((Vin+ - Vin-) - Vinit) / Vout
Strain = (-4Vratio / [GF * [(1 + υ) - 2Vratio (υ - 1)]]) * (1 + RL / Ro)
υ, Ro, RL, GF, Vinit and Vout are fixed values that are specified by the user in the
Constants Settings area, whereas (Vin+ - Vin-) are measured in realtime by
instruNet. Ro and Unstrained-Rgage must be the same value (e.g. 350ohms) in
order for the bridge to operate properly4.
To do axial Strain Gage measurement using a 1/2 Bridge circuit you must:
1. Do steps #1 through #7 listed in the previous "Strain Gage Measurement Quarter Bridge" discussion.
2. Set the Wiring field in the Hardware settings area to H Bridge Axial .
3. Set the v_Poisson field in the Constants settings area to the υ poissson value of
the material that you are twisting (e.g. aluminum is .32).
4. Wire your voltage source per figure 3.9, and refer to the steps at the beginning
of this chapter for more information on how to set up your sensor.5,10
3-15
Ch 3 Connecting to Sensors
Strain Gage
Measurement Full Bridge
(Bending)
Measuring bending strain using a full
bridge configuration involves wiring
four strain gages as shown in figure
3.10, applying a voltage across the
bridge, and measuring the voltage
across the two intermediate bridge
nodes via a pair of instruNet Vin+
and Vin- input terminals. The
excitation voltage for the bridge is
supplied by either the instruNet Vout
terminal or by an external voltage
source. instruNet calculates the
value of the strain, returning "strain"
engineering units,
using the equations:
Vout
Vin-
-ε
+ε
+ε
-ε
Vin+
Gnd
Fig 3.10 - Strain Measurement Full Bridge Circuit (Bending)
Vratio (V/V) = ((Vin+ - Vin-) - Vinit) / Vout
Strain = -Vratio / GF
GF, Vinit and Vout are fixed values that are specified by the user in the Constants
Settings area, whereas (Vin+ - Vin-) are measured in realtime by instruNet.
To do bending Strain Gage measurement using a Full Bridge circuit you must:
1. Do steps #1 through #7 listed in the previous "Strain Gage Measurement Quarter Bridge" discussion.
2. Set the Wiring field in the Hardware settings area to F Bridge Bend.
3. Wire your voltage source per figure 3.10, and refer to the steps at the beginning
of this chapter for more information on how to set up your sensor.5,10
Strain Gage
Measurement Full Bridge
(Axial I)
3-16
Measuring axial strain using a full
bridge configuration involves wiring
four strain gages as shown in either
figure 3.11 or figure 3.12, applying a
voltage across the bridge, and
measuring the voltage across the two
intermediate bridge nodes via a pair
of instruNet Vin+ and Vin- input
terminals. The excitation voltage for
the bridge is supplied by either the
instruNet Vout terminal or by an
external voltage source. instruNet
calculates the value of the strain,
returning "strain"
engineering units, using the equations:
V
out
V in
V +
in
Gnd
-υε
+ε
+υε
-ε
Fig 3.11 - Strain Measurement - Full
Bridge Circuit (Axial I)
Ch 3 Connecting to Sensors
Vratio (V/V) = ((Vin+ - Vin-) - Vinit) / Vout
Strain = -2Vratio / GF ( υ + 1)
υ, GF, Vinit and Vout are fixed values that are specified by the user in the
Constants Settings area, whereas (Vin+ - Vin-) are measured in realtime by
instruNet.
To do Axial Strain Gage measurement using a Full Bridge circuit you must:
1. Do steps #1 through #7 listed in the previous "Strain Gage Measurement Quarter Bridge" discussion.
2. Set the Wiring field in the Hardware settings area to F Bridge Axl I.
3. Set the v_Poisson field in the Constants settings area to the υ poison value of
the material that your are twisting (e.g. aluminum is .32).
4. Wire your voltage source per figure 3.11, and refer to the steps at the beginning
of this chapter for more information on how to set up your
Strain Gage
Measurement Full Bridge
(Axial II)
Measuring axial strain using a full
V
-υε
+ε
out
bridge configuration involves wiring
V four strain gages as shown in figure
in
3.12, applying a voltage across the
V +
bridge, and measuring the voltage
in
across the two intermediate bridge
-ε
-υε
Gnd
nodes via a pair of instruNet Vin+
and Vin- input terminals. The
excitation voltage for the bridge is
Fig 3.12 - Strain Measurement supplied by either the instruNet Vout
Full Bridge Circuit (Axial II)
terminal or by an external voltage
source. instruNet calculates the
value of the strain,
returning "strain" engineering units, using the equations:
Vratio (V/V) = ((Vin+ - Vin-) - Vinit) / Vout
Strain = -2Vratio / [GF [( υ + 1) − Vratio (υ − 1)]]
υ, GF, Vinit and Vout are fixed values that are specified by the user in the
Constants Settings area, whereas (Vin+ - Vin-) are measured in realtime by
instruNet.
To do Axial Strain Gage measurement using a Bridge circuit you must:
1. Do steps #1 through #6 listed in the previous "Strain Gage Measurement Quarter Bridge" discussion.
2. Set the Wiring field in the Hardware settings area to F Bridge II .
3-17
Ch 3 Connecting to Sensors
Temperature measurement using a voltage
divider circuit involves connecting an RTD in
series with a shunt resistor of known value,
applying a voltage across the pair and
measuring the voltage across the RTD, as
illustrated to the right. The voltage across the
RTD is measured between a pair of instruNet
Vin+ and Vin- input terminals while the
excitation voltage for the divider is supplied
by the instruNet Vout terminal. instruNet
calculates the value of the strain using the
following equations, and returns "degrees C"
engineering units.
V
out
V in
V +
in
Gnd
RTD
Temperature
Measurement
(RTD) Voltage
Divider1
R shunt
3. Set the v_Poisson field in the Constants settings area to the υ poisson value of
the material that your are twisting (e.g. aluminum is .32).
4. Wire your voltage source per figure 3.12, and refer to the steps at the beginning
of this chapter for more information on how to set up your sensor.5,10
Fig 3.13 - Temperature
Measurement (RTD) Voltage
Divider Circuit
RRTD (Ohms) = Rshunt * (Vin+ - Vin-) / (Vout - (Vin+ - Vin-))
a = Ro * alpha (1.0 + (delta / 100.0))
b = Ro * -1.0 * alpha * delta / (100.0 * 100.0)
c = Ro - RRTD
Temperature (Celsius) = c / (-0.5 * (b + sqrt((b*b) - (4.0 * a * c))))
Alpha is the temperature coefficient of the RTD at 0C (typically .00385 for
American RTD's, and .00392 for European RTD's) and delta is the Callendar-Van
Dusen delta constant (typically 1.492). These constants are often supplied by the
manufacturer of the RTD. The instruNet temperature linearizer only supports
temperatures above 0°C.
Many RTD manufacturers recommend a 1mA RTD current source with RTD
voltage dividers since this often dissipates several milliwatts, and therefore does
not cause noticeable "self" heating. An example would be a 100 ohm RTD (which
will vary from 25 to 400 ohms as the temperature varies; i.e. 25% to 400%), a 4.5V
excitation voltage (i.e. Vout) and a 5000 ohm shunt resistor. The average current
and power dissipation of the RTD at 0°C would be:
Current (Amps) = Volts / Resistance = 4.5V / [5000 + 100] = .88mA
Power (watts) = Current * Current * Resistance = .0088 * .0088 * 5100 = 3.8mW
The voltage across the RTD would vary from 22mV to 352mV as the resistance
across the RTD changed from 25 to 400 ohms (corresponding to a temperature
change of -260 to +850 Celsius); therefore, an input Voltage Range of ±600mV
would be ideal with a 100 ohm RTD, 4.5V Vout voltage, and 5000 ohm resistor.
3-18
Ch 3 Connecting to Sensors
To do temperature measurement using an RTD in a voltage divider circuit you
must:
1. Set the Sensor field in the Hardware settings area to RTD.
2. Set the Wiring field in the Hardware settings area to Voltage Divider .
3. Set the Voltage Range field in the Hardware settings area to something similar
to Vout * (RTD_Max / (Rshunt + RTD_Max )), where RTD_Max is the RTD
resistance at 0°C times 4.
4. Set the Rshunt field in the Constants settings area to Rshunt.1,3,6
5. Set the Ro field in the Constants settings area to the resistance of the RTD at
0°C, in ohms units.
6. Set the Vout field in the Constants settings area to specify the excitation
voltage that is to be applied to the divider. In high current cases (e.g. >2mA),
it is often helpful to alternate the polarity of the excitation voltages to evenly
burden the +/-12V supplies.11
7. Set the alpha field in the Constants settings area to the alpha value of your
RTD.
8. Set the delta,Rlead field in the Constants settings area to the delta value of your
RTD.
9. Wire your voltage source per figure 3.13, and refer to the steps at the beginning
of this chapter for more information on how to set up your sensor. To reduce
noise, 0.001 seconds of integration is often helpful (i.e. set the Integrate field in
the Hardware setting area to 0.001). 5, 10
Temperature
Measurement
(RTD) Bridge
Circuit
Temperature measurement using an RTD in
a bridge circuit involves wiring an RTD as
one leg of a full-bridge circuit, applying a
voltage across the bridge, and measuring
the voltage across the two intermediate
bridge nodes via a pair of instruNet Vin+
and Vin- input terminals. The excitation
voltage for the bridge is supplied by either
the instruNet Vout terminal or by an
external voltage source. In figure 3.14
RRTD is an RTD and Ro is a resistor of
known, similar, value. instruNet calculates
the value of the temperature, returning
degrees Celsius
engineering units, using the equations:
Vout
VinVin+
Gnd
Ro
Ro
Ro
R RTD
Fig 3.14 - Temperature
Measurement (RTD) Bridge Circuit
RRTD (Ohms) = (Ro * (Vout - 2.0 * (Vin+ - Vin-)) / (Vout + 2.0 * (Vin+ - Vin-))
a = Ro * alpha (1.0 + (delta / 100.0))
b = Ro * -1.0 * alpha * delta / (100.0 * 100.0)
c = Ro - RRTD
Temperature (Celsius) = c / (-0.5 * (b + sqrt((b*b) - (4.0 * a * c))))
3-19
Ch 3 Connecting to Sensors
Alpha is the temperature coefficient of the RTD at 0C (typically .00385 for
American RTD's, and .00392 for European RTD's) and delta is the Callendar-Van
Dusen delta constant (typically 1.492). These constants are supplied by the
manufacturer of the RTD. The instruNet temperature linearizer only supports
temperatures above 0°C.
The RTD bridge circuit is very accurate when the RTD resistance is close to the Ro
bridge resistance. (i.e. the RTD resistance varies between .5 * Ro and 2 * Ro). If
you need more RTD temperature range, please use the RTD Voltage Divider
circuit.
To do temperature measurement using an RTD in a bridge circuit you must:
1. Set the Sensor field in the Hardware settings area to RTD.
2. Set the Wiring field in the Hardware settings area to Bridge.
3. Set the Range field in the Hardware settings area to something small such as +/100mV.
4. Set the Ro field in the Constants settings area to the resistance of the RTD at
0°C, in ohms (typically, this is also be the bridge completion resistor
resistance).3,4
5. Set the alpha field in the Constants settings area to the alpha value of your
RTD.
6. Set the delta,Rlead field in the Constants settings area to the delta value of your
RTD.
7. Set the Vout field in the Constants settings area to specify the voltage that is to
be applied to the bridge (1V is typical). If you are applying an external
excitation voltage, enter -Ro value in the Ro edit field (e.g. -100 instead of 100
ohms) to tell the software that the excitation is external, and then enter the
value of the external excitation voltage into the Vout field (e.g. 4V).2 In high
current cases (e.g. >2mA), it is often helpful to alternate the polarity of the
excitation voltages to evenly burden the +/-12V supplies.11
8. Wire your voltage source per figure 3.14, and refer to the steps at the beginning
of this chapter for more information on how to set up your sensor. To reduce
noise, 0.001 seconds of integration is often helpful (i.e. set the Integrate field in
the Hardware setting area to 0.001).5,10
3-20
Ch 3 Connecting to Sensors
Temperature
Measurement
Thermocouple
Temperature measurement using a
thermocouple involves connecting the two
thermocouple leads to a pair of instruNet
Vin+ and Vin- input terminals. If this
voltage floats with respect to the instruNet
Gnd terminal, it might be necessary to also
attach the instruNet Vin- terminal to the
instruNet Gnd terminal with a short wire.
Sometimes this wire makes things better,
and sometimes this wire makes things
worse. instruNet calculates the value of the
temperature in degrees Celsius using a
polynomial linearizing equation.
V
out
V in
Tc
V +
in
Gnd
optional ground
Fig 3.15 - Temperature
Measurement (Thermocouple)
To do temperature measurement using a thermocouple you must:
1. Set the Sensor field in the Hardware settings area to the appropriate
Thermocouple type (J, K, T, E, R, S).
2. Set the Wiring field in the Hardware settings area to Vin+ - Vin-.
3. Set the Range field in the Hardware settings to either +/- 80mV or +/- 10mV
(approximately) depending on the temperature range being measured. If your
temperature range is <170C for a type J thermocouple, <230C for a type K
thermocouple, <180C for at type T thermocouple, <900C for a type R
thermocouple, <900C for a type S thermocouple or between -250C to 140C for
type E thermocouple, then set the range to approximately +/- 10mV. Otherwise
set the Range for approximately +/- 80mV. Measurement resolution is
approximately 1.2µV in the +/- 10mV range and approximately 10µV in the +/80mV range.
4. Wire your voltage source per figure 3.15, and refer to the steps at the beginning
of this chapter for more information on how to set up your sensor.5,10 If your
thermocouple leads are backwards, then the measured temperature will be
shown as varying in the opposite direction from ambient (e.g. if the instruNet
terminals are at 25°C, the thermocouple is at 35°C, and the leads are
backwards, then instruNet will report 15°C.).
5. For debugging help, please see Application Note #71 Thermocouple
Troubleshooting. Attaching Vin- to Gnd with a small wire solves many RFI
problems. Integrating for .001 to .001666 seconds solves many noise problems.
3-21
Ch 3 Connecting to Sensors
R shunt
Thermistors are two wire devices whose
resistance varies with temperature in a known
V
fashion, often accurate to +/- 0.2°C. The
out
instruNet thermistor measurement feature
V in
supports ysi-Omega 100ohm to 1Mohm
V +
thermistors between the temperatures of in
80°C to 250°C. When Thermistor is selected
Gnd
in the Sensor popup, instruNet assumes a
thermistor is connected in the prescribed
fashion, and subsequently returns the
thermistor temperature in degrees C units
Fig 3.16 - Temperature
after applying a Steinhart & Hart resistanceMeasurement (Thermistor)
Voltage Divider Circuit
to-temperature conversion. Measuring a
thermistor temperature involves a voltage
divider circuit with a shunt resistor of known value, applying a voltage across the
pair and measuring the voltage across the thermistor, as illustrated to the right. The
voltage across the thermistor is measured between a pair of instruNet Vin+ and
Vin- input terminals while the excitation voltage for the divider is supplied by the
instruNet Vout terminal. instruNet calculates the thermistor resistance using the
following equation.
R unknown
Thermistor
Temperature
Measurement
RTherm (Ohms) = Rshunt * (Vin+ - Vin-) / (Vout - (Vin+ - Vin-))
TemperatureTherm (°C) = -273.15 + 1.0 / (a + b (Ln( RTherm )+c (Ln( RTherm ))3)
a, b, and c are a function of 3 points in the resistance-to-temperature table, and are
calculated by instruNet after the user completes a short dialog box interview. To
minimize "self heating", it is recommended that thermistors operate at less than
100uW (50uW is better). An example would be a 2252 ohm thermistor (which will
vary from 394.5 to 7355 ohms in the 0-70°C temperature range). With 0.37V
excitation voltage (i.e. Vout) and a 1000 ohm shunt resistor, the current and power
dissipation at 70°C would be 100uW:
Current (Amps) = Volts / Resistance = 0.37V / [1000 + 394.5] = .265mA
Power (watts) = Current 2 * Resistance = .0002652 * 1394.5 = 100uW
The voltage across the thermistor would vary from 104mV to 320mV as the
resistance across the thermistor varied from 394 to 7355 ohms; therefore, an input
Voltage Range of ±.6V would work nicely in this case. Shunt resistors with an
initial accuracy of .025%, and a temperature drift of 20ppm/°C, such as the
Caddock part #TN130-resistance-0.025%-20, are recommended1,3,6.
To do temperature measurement using a Thermistor, the user must:
1. Set the Sensor field in the Hardware settings area to Thermistor. This will
cause a series of dialog boxes to appear, asking the user several questions about
the thermistor type (i.e. resistance at 25°C), shunt resistor value, and excitation
voltage. It also recommends an excitation voltage and shunt resistor value
based on the thermistor in use, and the temperature range of interest -- in many
3-22
Ch 3 Connecting to Sensors
cases, using the recommended values are the best options. Based on the
responses to these questions, instruNet loads the following fields in the
Constants setting group, with the following information:
Ro
thermistor resistance at 25°C, in units of ohms
Rshunt actual shunt resistance, in units of ohms
Vout
excitation voltage output the Vout screw terminal
alpha
the 'a' Steinhart & Hart coefficient
delta,Rlead the 'b' Steinhart & Hart coefficient
GF
the 'c' Steinhart & Hart coefficient
V_poisson
the maximum expected temperature, in degrees C units
Vinit
the minimum expected temperature, in degrees C units
instruNet also sets the Voltage Range field in the Hardware settings area to a
value appropriate to the specified temperature range. The smaller the
temperature range, the better the accuracy; therefore one should not make the
specified range unnecessarily large.
If you want to run through the dialog box interview again, select Voltage in the
Sensor field, and then select Thermistor, to invoke the interview again.
If you want to manually set any of the fields in the Constants settings group, do
the interview, and then set them to your liking, after selecting Constants in the
Settings popup.
2. Wire your thermistor per figure 3.16, and refer to the steps at the beginning of
this chapter for more information on how to set up your sensor. To reduce
noise, 0.001 seconds of integration is often helpful (i.e. set the Integrate field in
the Hardware setting area to 0.001) 5, 10.
Load Cell
Measurement
A load cell is an external
V
-υε
+ε
out
device similar to a strain
V gage that measures force
in
in Kg or LBs units. The
V +
i100xx connects directly
in
to load cells by providing
-ε
-υε
Gnd
an excitation voltage and
returns Kg or LBs units to
the end user. When one
Fig 3.17 - Load Cell Measurement
selects "Load Cell" in the
"Sensor" field, an
interview leads the user through the setting up of the device. One enters
parameters such as device resistance (ohms), excitation voltage specified on
package label (V), maximum force (Kg or LB) at specified excitation voltage, and
mV/V sensitivity (e.g. one enters "2" if the package label specifies 2mV/V).
Load cells are set up in a bridge circuit where a voltage is applied across the bridge,
and the voltage across the two intermediate bridge nodes is measured via a pair of
3-23
Ch 3 Connecting to Sensors
instruNet Vin+ and Vin- input terminals. The excitation voltage for the bridge is
supplied by either the instruNet Vout terminal or by an external voltage source.
instruNet calculates the force using the equations:
Vratio (V/V) = ((Vin+ - Vin-) - Vinit) / Vout
Force (Kg) = Vratio / Sensitivity
Sensitivity = Vmeas per Vexc per Kg, as specified on package label
Ro (bridge resistance in ohms), GF (Vmeasure per Vexcitation per Kg, as
specified on the physical sensor label), Vinit (Voltage measured with 0 force, used
to calibrate 0) and Vout are fixed values that are specified by the user in the
Constants Settings area (indirectly if set via the interview), whereas (Vin+ - Vin-)
are measured in realtime by instruNet. For more details, please see Application
Notes #14 Strain Gages, #75 Load Cells, and #139 Ratio Measurements.
To do a Load Cell measurement, you must:
1. Set the Sensor field in the Hardware settings area to Load Cell.
2. Set the Range field in the Hardware settings area to +/- 10mV.7
3. Set the Ro field in the Constants settings area to the value of one Ro bridge
completion resistor, in ohms units.3,4
4. Set the GF field in the Constants settings area to the sensors sensitivity in
Vmeasure per Vexcitation per Kg units.
5. Set the Vout field in the Constants settings area to specify the voltage that is to
be applied to the bridge (1V is typical). If you are applying an external
excitation voltage, enter -Ro value in the Ro edit field (e.g. -100 instead of 100
ohms) to tell the software that the excitation is external, and then enter the
value of the external excitation voltage into the Vout field (e.g. 4V).2 In high
current cases (e.g. >2mA), it is often helpful to alternate the polarity of the
excitation voltages to evenly burden the +/-12V supplies.11
6. Set the Vinit field in the Constants settings area to the voltage measured when 0
force is applied, in Volts units.8
7. Set the Wiring field in the Hardware settings area to Bridge.
8. Capacitors across the voltage input terminals are highly recommended for
reducing errors caused by RFI. With 350ohm sensors, 0.1uF caps create a low
pass filter at 4KHz [4K = 1 / (6.28 * 350 * .1e-6)], and are ideal at minimizing
RFI effects.
9. Wire your voltage source per figure 3.17, and refer to the steps at the beginning
of this chapter for more information on how to set up your sensor.5,10
3-24
Ch 3 Connecting to Sensors
Accelerometer
Measurement
An Accelerometer is an
external device that
measures acceleration in
G units. They contain an
internal constant mA
excitation current and
provide a voltage output
to the instruNet, which
does not provide
excitation.
Vout
_
Vin
+
Vin
+
Voltage
Source
Gnd
+
Voltage
Source
_
_
Fig 3.18 - Accelerometer Measurement,
Single-Ended Wiring
The i100xx connects directly to accelerometers and returns G units to the end user.
When one selects "Accelerometer" in the "Sensor" field, an interview leads the user
through the setting up of the device. One enters parameters such as maximum and
minimum acceleration (G units) and mV per G sensitivity as specified on the
physical package label (e.g. one enters "2" if the package label specifies 2 mV/G).
Accelerometers are set up in either single-ended or differential wiring mode.
Figure 3.18 shows a single-ended configuration, yet one can implement differential
by wiring as shown in Figure 3.2 and setting the "Wiring" field to differential
"Vin+ - Vin-". instruNet calculates acceleration using the equations:
Vmeasure (V) = (Vin+ - Vin-) or Vin+ or VinAcceleration (G) = Vmeasure / Sensitivity
Sensitivity = Vmeasure per G, as specified on package label
GF (Vmeasure per G) is a fixed value that is specified by the user in the Constants
Settings area (indirectly if set via the interview), whereas Vmeasure is measured in
realtime by instruNet. To do an Accelerometer measurement, you must:
1. Set the Sensor field in the Hardware settings area to Accelerometer.
2. Set the Range field in the Hardware settings area to accommodate the
maximum accelerometer voltage (e.g. +/- 5V).
3. Set the GF field in the Constants settings area to the sensors sensitivity in
Vmeasure per G units.
4. Set the Wiring field in the Hardware settings area to either differential "Vin+ Vin-" (figure 3.2) or single-ended "Vin - Gnd" (figure 3.18), and refer to the
steps at the beginning of this chapter for more information on how to set up
your sensor.5,10
3-25
Ch 3 Connecting to Sensors
Potentiometer
Measurement
A potentiometer (pot) is
an external device that
measures linear distance
or rotation angle. The
i100xx connects directly
to pots by providing
excitation at 4V and
returns data in variable
0.0 to 1.0 units (e.g. 0.1
would represent 27
Fig 3.19 - Potentiometer Measurement
degrees on a 270 degree
rotation pot). One can scale this 0 to 1 data to other units using the Channel
Mapping dialog. We recommend 5K to 25K ohm pots since lower values may
overload the Vout driver and higher values may incur excess noise. Figure 3.19
shows the Vin- terminal being wired to the sensor, yet a jumper wire between Vinand Gnd will work as well.
When one selects "Potentiometer" in the "Sensor" field, an interview leads the user
through the setting up of the device. One enters parameters such as pot maximum
resistance (ohms). The excitation voltage for the pot is supplied by either the
instruNet Vout terminal or by an external voltage source. instruNet calculates the
pot position using the equation:
Potposition (0 to 1) = ((Vin+ - Vin-) - Vinit) / Vout
Vinit (Voltage measured in CCW position, used for calibration) and Vout are fixed
values that are specified by the user in the Constants Settings area (indirectly if set
via the interview), whereas (Vin+ - Vin-) are measured in realtime by instruNet.
To do a Potentiometer measurement, you must:
1. Set the Sensor field in the Hardware settings area to Potentiometer.
2. Set the Range field in the Hardware settings area to +/- 5V.
3. Set the Ro field in the Constants settings area to the value of the potentiometer
maximum resistance, in ohms units. 5K to 25K are recommended.
4. Set the Vout field in the Constants settings area to specify the voltage that is to
be applied to the potentiometer (4V is typical). If you are applying an external
excitation voltage, enter -Ro value in the Ro edit field (e.g. -10000 instead of
10000 ohms) to tell the software that the excitation is external, and then enter
the value of the external excitation voltage into the Vout field (e.g. 4V).2 In
high current cases (e.g. >2mA), it is often helpful to alternate the polarity of the
excitation voltages to evenly burden the +/-12V supplies.11
5. Set the Vinit field in the Constants settings area to the voltage measured when
the pot is in the CCW position, in Volts units.8
6. Set the Wiring field in the Hardware settings area to Bridge.
7. Wire your potentiometer per figure 3.19, and refer to the steps at the beginning
of this chapter for more information on how to set up your sensor.5,10
3-26
Ch 3 Connecting to Sensors
Sensor Reference Footnotes
1 Heating Considerations with Resistors
When current is pumped through a resistor, it heats up. When a resistor heats up,
its resistance changes, and this can cause errors in your measurement. The current
though a resistor is calculated via:
Current (Amps) = Volts Across Resistor / Resistance in ohms
The power dissipated by a resistor is:
Power Dissipated (Watts)
= Volts * Volts / Resistance
= Current * Current * Resistance
The amount a resistor heats up is:
Change in Temperature (Celsius) = Thermal Resistance (C/Watt)
* Power Dissipated (Watts)
The amount a resistor changes for a change in temperature is:
Change in Resistance (ohms) = Change in Temperature (Celsius)
* Temperature Coefficient (ppm/C)
* Resistor Value (ohms)
For example, a 100ohm resistor with a 100 ppm/C temperature coefficient and
30C/Watt thermal resistance that is passing 50 milliAmps would enjoy the
following situation:
5Volts across resistor = 100ohms * 50mA
0.25Watts power dissipation = 5V * 5V / 100ohms
7.5°C temperature change = 30C/Watt * .25Watts
0.075 ohms change due to temperature change = 7.5°C temp
change * .0001ohms/ohm/C thermal resistance * 100 ohms
2 Excitation Voltages for Bridge Circuits
If you type an unreasonably high value into the Vout field of the Constants area
and press Enter, instruNet will set the output voltage to the highest possible value
without allowing the internal output amplifier to saturate (e.g. ≤ 4mA for #iNet100/100B and ≤15mA for #iNet-100HC). Setting the highest possible Vout,
causes the highest possible voltage to be read by the Vin terminals, which increases
the signal to noise ratio and therefore increases accuracy. The downside to having
a high excitation voltage is that it increases the power dissipated by the resistors,
which increases their thermal heating, which increases the drift from their
resistance's at ambient temperature (e.g. typical resistors offer 100ppm resistance
drift per degree C change in temperature). Resistors with low temperature
coefficients (e.g. 25ppm/C) are helpful if this is a problem. Also, if noise is a
problem, it is sometimes helpful to install a capacitor (e.g. 1µF) between the Vout
terminal and GND, at the bridge (possibly far from instruNet), to hold the
excitation voltage steady.
3 Shunt Resistors and Bridge Completion Resistors
Bridge completion resistors and shunt resistors should be as accurate as possible
(.1% is often ok, .01% is very good), and have a low temperature coefficient
3-27
Ch 3 Connecting to Sensors
(25ppm/C is often ok, 5ppm/C is very good). If you use a less accurate resistor, we
recommend that you measure it with a DVM, and then type this more accurate
value into the Rshunt field in the Constants setting area. To determine the effect of
a resistor inaccuracy, calculate your engineering units for a typical case, and then
increase the resistor value by its expected error, and note the change in the
resulting engineering units output. For example, if a 100ohm shunt resistor is used
to measure a 1mA current source and it changes 1%, then the measured reading
would change 1%, or .01mA.
Several manufacturers of resistors are listed below:
a. Caddock Electronics Inc, USA telephone 1-541-496-0700, Ask for "Greg, The
Resistor Man" or a "Resistor Applications Engineer", fax 1-541-496-0408.
Caddock offers very precise resistors in the $2 to $20 range. The "MK132 Value - Tolerance" series parts are 3/4W, 30-5Mohms, .1% to 5% initial
accuracy, 50ppm/C; and the "TF020R - Value - Tolerance - Temperature
Coefficient" series parts are .33W, 1K-2Mohms, .01% to 1%, 5 to 15ppm/C.
They accept VISA and MasterCard, have no minimum order, and often have
items in stock.
b. Digi-Key Corporation, USA telephone 1-800-344-4539, fax 1-218-681-3380.
Part # "value X-ND" are $.50, 1/4Watt, 100ppm/C temperature drift, 1% initial
accuracy Resistors that are not too accurate yet very easy to order and are low
cost.
c. "RN 55 E value 0.1%" resistors are a common series that offers 1/8Watt, 0.1%
initial accuracy, and 25ppm/C temperature drift for approximately $1. Also,
the "RNC 60H value 0.1%" series is similar, yet with 50ppm/C temperature
drift at 1/4W. These are manufactured by folks like IRC Inc, and Dale Inc; and
distributed by companies like Newark Electronics (USA telephone 800-4639275, fax 1-312-907-5217) and Allied Electronics (USA telephone 1-800-4335700, fax 1-817-595-6444). They accept common credit cards, and if one
series is not in stock, ask them to suggest something that is similar.
4 Bridge Completion Resistors in Strain Gage Bridge Circuits
In a bridge, all 4 resistors must be the same value, within 10% or so (1% is better,
.1% is excellent), in order for the bridge to operate properly. In some bridge
circuits, all 4 resistors are supplied by the sensor manufacturer; whereas in others
(e.g. 1/4 or 1/2 bridge circuits), the user must supply "completion" resistors of the
same value as the gage to complete the bridge circuit. This can be done by
installing precision resistors (e.g. 0.1%), or by installing fixed unstrained strain
gages of the same ohmic value.3
5 Filter Settings for Low Level Measurements
Strain gage, thermocouple, and RTD voltages are typically very low and therefore
often require low pass filtering to reduce noise. Low pass filters cause high
frequencies to be rejected, while low frequencies are passed. Visually, the signal
becomes "smoother". instruNet provides several low pass filter options:
3-28
Ch 3 Connecting to Sensors
a) The Low Pass popup menu in the Hardware settings area can select a variety of
analog low pass filter options (e.g. the Model 100 provides the following
analog one pole low pass options: off, 40Hz, and 4KHz).
b) The Integrate field in the Hardware Settings area selects how long the signal is
averaged before instruNet returns one number. This "averaging", in effect, is a
low pass filter. Careful, this averaging fully consumes the instruNet controller,
and therefore reduces the maximum possible sample rate. A 0.001 sec
integration time is often very helpful at reducing noise and increasing accuracy.
c) The Low Pass settings area provides a means by which one can digitally filter a
signal, post acquisition, with tremendous accuracy.
d) The user can manually place a capacitor across the Vin+ and Vin- input
terminals with any bridge or voltage divider circuit to provide a 1pole low pass
filter where the cut-off Frequency in Hertz is equal to 1 / (2 * π * R * C); where
R is the source resistance in ohms, C the parallel capacitance in Farads, and π
is 3.14159.
6 Selecting a Voltage Divider Shunt Resistor
Shunt resistor values are typically chosen to cause a large voltage (several volts
maximum) to be measured by instruNet, without heating up the resistor
significantly to cause its resistance to change or causing the excitation voltage
source to over shoot its maximum output current (e.g. 4mA on the #iNet-100/100B
and 15mA on #iNet-100HC). If the Rshunt value is low, then the voltage across it
is low, and this decreases the signal to noise ratio of the measured signal. Also,
Rshunt must be selected such that the voltage across Runknown does not exceed
the instruNet maximum input voltage (e.g. +/-5V with the Model 100). Due to
these limitations, instruNet might not let you set some of the fields too high or too
low.
7 Voltage Range Settings For Strain Gages
Since strain gage voltages are often very small, a small input range (e.g. +/- 10mV)
works best for most measurements. Increasing the voltage range increases the
range of strain that can be read, while sacrificing accuracy with small voltages (e.g.
instruNet can read 5mV more accurately with a +/-10mV range, than with a +/100mV range). Please refer to your equation for details on how strain relates to
voltage measured.
8 Balancing your Bridge with the Vinit Correction Voltage
Vinit is the voltage measured across the intermediate nodes of the bridge when the
strain gage(s) are unstrained in a bride circuit. This is measured by putting
instruNet into Voltage mode, Differential Wiring, with a low voltage Range (e.g.
+/-10mV), and then measuring the resulting bridge voltage (e.g. via the value
shown at the bottom of the Probe dialog). You must then enter this voltage value
into the Vinit field in the Constants settings area, reset your Sensor field to Strain
Gage, and reset your Wiring field to where you had it. Subsequently, all reported
"strain" values will reflect resistance changes from the "unstrained" scenario. Vinit
is used as an offset correction factor to "balance" the bridge. If you do not want to
go through the trouble of "balancing" your bridge, simple set Vinit to 0.
3-29
Ch 3 Connecting to Sensors
9 The Strain Gage "GF" Factor
All strain gages are manufactured with a specific Gage Factor (GF), which relates a
change in resistance, to strain. The GF is often printed on the strain gage package,
and must be correctly entered into the instruNet GF field within the Constants
settings area. This is used to calculate the "strain" value returned by instruNet.
10 Accuracy of Measurements
Accuracy measurements are affected by the noise pickup on the leads, the accuracy
of the sensor itself (i.e. thermocouple's are typically accurate to +/- 1C to 3C) and
the instruNet measuring system. A noisy environment and long sensor leads are
often the worst threat to accuracy. Integrating (via the Integrate field) a signal over
a period of time will give a more accurate measurement by filtering out noise at the
expense of a lower maximum sample rate.
An example of how to calculate accuracy is as follows:
Suppose you are doing a current measurement where the current is calculated as the
voltage drop across a shunt resistor divided by the resistance in ohms of the
resistor.
Current (Amps) = Volts across shunt resistor / shunt resistance in ohms
Suppose the measured voltage is accurate to 1mV and the 1K ohm shunt resistor is
accurate to 1%. Subsequently, the accuracy of the measured current would be
Max Current Error = 1mV / (.01 * 1K) = 100microAmps
11 Alternating Positive and Negative Excitation Voltages
To reduce the burden on one side of a power supply (e.g. +12V or -12V), excitation
voltages often alternate positive and negative. For example, when powering
350ohm strain gages, the excitation voltages are typically set to {+5V, -5V, +5V, 5V...}. The alternating polarity evenly burdens the +/-12V supplies. Please note
that in low current cases (e.g. <2mA), this is not necessary.
3-30
Ch 4 Hardware Reference
Chapter 4, A Tutorial For
Programmers
This chapter explains how to control instruNet from a programming environment
such as C or Visual Basic. It assumes you have done the tutorial in Chapter 2, in
its entirety. If you haven't, please do so now. This chapter also assumes you have
a working knowledge of your programming language and programming tools.
Getting Started Quickly
The instruNet Setup.exe installer file version >= 1.4 for Windows includes
instruNet programming interfaces for the following languages:
•
•
•
•
•
Microsoft
Microsoft
Microsoft
Microsoft
Microsoft
Visual
Visual
Visual
Visual
Visual
Studio C/C++ 5
Studio .Net C/C++ 7
BASIC 4
BASIC 6
Studio .Net BASIC 7
Documentation resides at:
•
•
•
Select under Windows START Menu: All Programs / instruNet /
Programming Interfaces /.
See instruNet Programming Application Notes
See Chapter 4 of the instruNet Manual (i.e. this chapter).
Interface files reside at the following Windows directory after running the
instruNet Setup.exe installer program.
•
Program Files \ instruNet \ Programming Interfaces \
4-1
Ch 4 Hardware Reference
Programming Overview
An instruNet data acquisition system is controlled with one main subroutine,
called iNet(), that is callable from C or Visual Basic. The actual iNet() code
resides in the instruNet Driver file that you installed in Ch 1 (i.e. Macintosh
Code Resource or a Windows 32bit DLL).
iNet()
Function Call
The iNet() function includes 7 parameters that specify a field in the network
hierarchy that is to be read or written to, as shown below:
iNetINT16 iNet(
iNetUINT8 netNum,
NETWORK number = {0...numNetworks}, 0 is
Driver, 1 is 1st Controller installed
into the computer, 2 is the 2nd
Controller, etc.
iNetUINT8 deviceNum,
DEVICE number {0...numDevices}, 0 =
"Controller", 1 = 1st device on net...
iNetUINT8 moduleNum,
MODULE number within a hardware DEVICE
{1...32}. Each DEVICE can contain up to
32 separate modules. Many devices have
only 1 module.
iNetUINT8 chanNum,
Hardware CHANNEL number {1...32}. Each
device contains a number of channels
(i.e. signals that are accessed//via a
screw terminal or connector), each of
which has its own channel #.
iNetINT16 fieldGroupNumOrType,
If > 0, this is a field Group Number
{1...numFieldGroups}. if < 0, this is a
field Group Type.
iNetINT16 fieldNum,
Field number within the fieldGroup of
the CHANNEL.
iNetUINT8 intention
ion_intention = {intention_getValue,
intention_setValue,
intention_getNameStr,
intention_getMaxValue}
iNetUINT8 argType
argument type {int16, int32, str15,
etc}(void *ptrToArg) this is where data
is kept (we read or write to this
location).
These parameters specify a field, such as the cut-off frequency of a low pass
filter, the sample rate, or the actual real-time value of a channel. This function
can both read from and write to any field on the network. For a description of
each field, please refer to Ch 6. One uses iNet() to both set up the networks,
and then do I/O with the various channels. Also, iNet() can be used to tell the
instruNet Controllers to digitize, and then download the digitized data into
4-2
Ch 4 Hardware Reference
computer memory. iNet() is extremely powerful -- it can even open the
instruNet World window and turn over control to the user.
Simple Format
Functions
There are also a collection of Simple Format functions that read and write instruNet
fields using a structure that specifies a channel address {netNum, deviceNum,
moduleNum, chanNum}. This structure ("User Defined Variable Type" if in Visual
BASIC) is defined as follows:
typedef struct iNetChannelAddr {
iNetUINT8 netNum;
iNetUINT8 deviceNum;
iNetUINT8 moduleNum;
iNetUINT8 chanNum;
NETWORK number = {0...numNetworks}, 0 is
Driver, 1 is the first controller installed
into the computer.
DEVICE number = {0...numDevices}, 0 =
"Controller", 1 = 1st device on network.
MODULE number within hardware DEVICE {1-32}.
Many devices have only 1 module.
Hardware CHANNEL number {1...32}. Each device
contains a number of channels, each of has
which its own channel number.
} iNetChannelAddr;
To read or write an instruNet field with a Simple Format function, one must first
load an iNetChannelAddr structure with the netNum, deviceNum, moduleNum,
chanNum. This is often done with the LoadChannelAddress() routine:
LoadChannelAddress()
Specify an instruNet channel address.
After the structure is loaded (it holds the netNum, moduleNum, deviceNum,
chanNum information), one can then read or write an instruNet field with any of
the following routines:
SetField_int32()
SetField_uint32()
SetField_flt32()
SetField_cStr()
GetField_int32()
GetField_uint32()
GetField_flt32()
GetField_cStr()
Set instruNet field with 32bit signed
integer number.
Set instruNet field with 32bit unsigned
integer number.
Set instruNet field with 32bit floating
point number.
Set instruNet field with C string
(terminated with 0x00).
Read instruNet field into a 32bit signed
integer variable.
Read instruNet field into a 32bit unsigned
integer variable.
Read instruNet field into a 32bit floating
point variable.
Read instruNet field into a C string
variable (terminated with 0x00).
For example, the following C code would read the real-time value of Channel 1 at
Device 1, Module 1, Network 1:
iNetChannelAddr vin;
iNetFLT32 V;
iNetError e;
LoadChannelAddress(&vin, 1, 1, 1, 1);
V = GetField_flt32(&vin,sgt_General,fldNum_General_valueEu,&e);
4-3
Ch 4 Hardware Reference
Digitizing
There are several routines, summarized below, that are used to simultaneously
digitized channels to ram or to disk, as described in C file INET_INT.C and Visual
BASIC file INET_Common_Code.bas.
EnableChannelForDigitizing()
Mark this channel for digitizing (i.e. when
digitizing is started).
DisableAllChannelsForDigitizing()
Disable all channels for digitizing.
Set_iNet_TIMING_Parameters()
Set digitize timing parameters (e.g.
sampleRate, ptsPerScan, etc).
Set_iNet_TRIGGER_Parameters()
Set digitize trigger parameters (e.g.
trigger on/off, trigger source).
Service_All_iNet_Digitize_Buffers()
Services internal buffers while digitizing.
Access_Digitized_Data_In_Ram_Buffer()
Provides access to digitized data (even
during acquisition).
Simple digitizing is illustrated nicely in Example#2. In summary, to digitize, one
must:
1. Call DisableAllChannelsForDigitizing() to disable all channels for
digitizing.
2. Specify which channels are to be digitized by calling LoadChannelAddress()
and EnableChannelForDigitizing() for each digitize channel.
3. Specify timing parameters (e.g. sample rate) with Set_iNet_TIMING_Parameters().
4. Specify trigger parameters with Set_iNet_TRIGGER_Parameters().
5. Tell the instruNet driver to start digitizing with PRESS_iNet_BUTTON(
iNetCM_BtnPress_Record_Start ).
6. Periodically (e.g. 4 times per second) call
Service_All_iNet_Digitize_Buffers() to provide the instruNet Driver time to
service internal buffers (this is mandatory).
7. Call Access_Digitized_Data_In_Ram_Buffer() to access digitize data for each
channel.
Support
Functions
Additional functions defined and described in C file INET_INT.C, and in Visual
BASIC file INET_Interface.bas, are listed as follows:
UTILITY FUNCTIONS
iNet_Peek_int16()
iNet_Peek_int32()
iNet_Peek_flt32()
4-4
Reads 16bit integer number from a specific
logical address.
Reads 32bit integer number from a specific
logical address.
Reads 32bit floating point number from a
specific logical address.
Ch 4 Hardware Reference
iNet_Poke_int16()
iNet_Poke_int32()
iNet_Poke_flt32()
iNet_Get_VarPtr()
iNet_memcopy()
Writes 16bit integer number to a specific
logical address.
Writes 32bit integer number to a specific
logical address.
Writes 32bit floating point number to a
specific logical address.
Returns a pointer to the passed variable.
Copies memory block from one place to another.
ADVANCED FIELD READ/WRITE ROUTINES
iNet_int32()
iNet_uint32()
iNet_flt32()
iNet_cString()
iNet_pString()
iNet_DLL()
Reads or writes to a field
signed integer variable.
Reads or writes to a field
unsigned integer variable.
Reads or writes to a field
floating point variable.
Reads or writes to a field
variable.
Reads or writes to a field
string variable.
Reads or writes to a field
variable.
via a 32bit
via a 32bit
via a 32bit
via a C string
via a Pascal
via any type of
DRIVER ROUTINES
Load_instruNet_Driver()
Loads instruNet driver into memory.
CloseDriverAndReleaseDriverRam()
Closes instruNet driver and releases memory.
Show_ALERT_if_hit_iNet_Error()
Shows an alert if instruNet hit an error.
Show_Simple_Alert() Displays a message in an alert dialog box.
Get_iNet_Error()
Gets error code to last instruNet function
call.
Get_Last_iNet_Call() Returns pointer to struct with params to
last iNet call.
Interface Files
The instruNet disk includes interface files for C and Visual BASIC that
enable your program to call the above listed functions. No compiler object files
are used; therefore, you are not at the mercy of a specific version of a specific
compiler on a specific computer. Instead, you simply add the following glue
source code to your program:
VB Files
INET_Interface.vb
C Files
INET_INT.C
INET_Declarations.vb
INET_INT.H
INET_Macros.vb
INET_MCS.H
Interface Description
Contains low level source code that
interfaces to the instruNet driver.
Contains many low level enums and #defines
that support instruNet.
Contains macros that help set/read instruNet
fields.
Every instruNet C program must include the following files: INET_INT.C,
INET_INT.H, and INET_MCS.H.
Every instruNet Visual BASIC program must include the following files:
INET_Interface.vb, INET_Common_Code.vb, INET_Declarations.vb,
and INET_Macros.vb.
Programming
The instruNet disk includes example programs in Visual BASIC and C.
4-5
Ch 4 Hardware Reference
Examples
C Files
INET_EX1.C
The C Example #1 and VB Example #1 do the same thing, yet just in different
languages. In fact, they do many of the same things that are done in Ch 2
Tutorial. For example, in Ch 2, one is asked to turn on a low pass filter by
selecting a popup menu. Example#1 will do the same thing with the iNet()
function call. With instruNet, each task can be done automatically under
program control, or manually in the instruNet World window. This will
become more clear as you work with the example programs. The instruNet
disk includes the following example programs:
VB Files
EndUser Example1.sln
EndUser Example1.vb
INET_EX2.C
instruNet Data
Types
Example Description
This is a lengthy and comprehensive
example that shows how to call almost
every instruNet function in a text
window-based environment.
This is a simple example that shows how
to read and write instruNet fields and
how to digitize.
instruNet defines its own data types that allow you to keep your code platform,
machine, and operating system independent. instruNet data types are defined
in the file INET_INT.H. An example of an instruNet data type definition is:
typedef unsigned short iNetUINT16;
/* 16bit unsigned integer */
Always use instruNet data types when calling the instruNet driver and macros.
In this manual, the following are used to refer to variable types:
iNetINT8
iNetUINT8
iNetINT16
iNetUINT16
iNetINT32
iNetUINT32
iNetFLT32
signed 8bit integer, -128 to +127.
unsigned 8bit integer, 0 to +255.
signed 16bit integer, -32768 to +32767.
unsigned 16bit integer, 0 to +65536.
signed 32bit integer, -2,147,483,648 to
+2,147,483,647.
unsigned 32bit integer, 0 to +4,294,967,295.
32bit floating point number
instruNet Macros instruNet defines a number of macros for the more common driver calls. The
macros are defined in file INET_MCS.H. The macros are platform, machine and
operating system independent. An example of a macro call is:
OPEN_instruNet_WINDOW( instruNetCM_OpenWindow_Network );
which when called will open the Network Page of instruNet. The Network Page
could also have been opened by directly calling the instruNet C function:
iNet(netNum_DRIVER, deviceNum_CONTROLLER, moduleNum_1stModule,
driver_ChanNum_OpenWindow, sgt_General,
fldNum_General_valueEu, intention_setValue, instruNetDT_INT16,
(void *) ((gINT16TempArg = specificPage) ? &gINT16TempArg :
&gINT16TempArg));
Example
4-6
Example#1 does the following things using the instruNet interface functions.
Ch 4 Hardware Reference
Code
C source code is shown in Courier font.
1. Load instruNet Driver
The C code below calls Load_instruNet_Driver() to load the instruNet
Driver, and to get the number of installed controller cards. If the driver does
not load properly, an error is returned and Show_ALERT_if_hit_iNet_Error()
displays a dialog box with an error code. Please consult Appendix II for more
information on error codes.
iNetError e;
iNetINT16 driverIsInstalledOK, numNetworks;
e = Load_instruNet_Driver(TRUE /* reset_instruNet */,
&driverIsInstalledOK, &numNetworks);
if (e != iNetErr_None) {
Show_ALERT_if_hit_iNet_Error(e); return 0; }
2. Tell the instruNet Driver to open the Network Page Window
The C code below tells the driver to open the Network Page Window. From the
Network Page, fields can be viewed and set following the procedures in
Chapter 2 instruNet Tutorial. If a non zero error code is returned the program
will jump to an exit routine.
e = OPEN_instruNet_WINDOW( instruNetCM_OpenWindow_Network );
if (e) { goto Exit; }
3. Read several voltage inputs and set a voltage output
The next few lines of code read several voltage inputs and write to a voltage
output. They assume a Model 100 is attached to the 1st network controller
card.
4. Print the values for the first 5 channels on instruNet
The C code below calls the function Print_iNet_Channels() which reads one
value from each of the first five input channels of an instruNet Network, and
prints them to the console window. The function call is defined in file
INET_EX1.C.
e = Print_iNet_Channels(5);
if (e) { goto Exit; }
6. Print the first 3 Fields
The C code below calls the function Print_iNet_Fields() which scans the
network and prints the values of the first 5 fields that it finds. The function call
is defined in file INET_EX1.C
e = Print_iNet_Fields(3);
if (e) { goto Exit; }
7. Read and write instruNet Fields
The C code below calls the function ReadWriteFields_iNet() prompts the
user for a field address, displays the current value of the field and allows the
user to change the field value. The function call is defined in the program
INET_EX1.C.
e = ReadWriteFields_iNet();
4-7
Ch 4 Hardware Reference
if (e) { goto Exit; }
8. Digitize some analog input channels
The C code below calls the function SimultaneouslyDigitizeAndAnalyze()
which digitizes several channels. When writing code that acquires data
seamlessly it is important to continuously call
Service_All_iNet_Digitize_Buffers() while the data acquisition is
running. This function call is defined in the file Example#1 file.
e = SimultaneouslyDigitizeAndAnalyze();
if (e) { goto Exit; }
9. Modify the Example source code to meet your own needs.
Tutorial
Summary
In summary, the Programming Tutorial will involve the following steps:
1. Make sure you have done Ch2 Tutorial in its entirety.
2. Install your programming environment on your hard disk, load an example
program shipped with your Programming Language, compile, and then run to
verify that your Programming Environment is set up properly.
3. Create a new Folder/Directly on your hard disk. Make a copy of the
instruNet example program and place it into this folder, along with include
files.
4. Compile and link the code. If you have any compile or link errors, please
use the source code to debug the system -- all source code is provided.
5. Run the example programs to verify that the compiler, example files, driver,
and computer are all working well together.
6. Read the example program source code and comments to get a feel for
instruNet programming.
Getting
Started
To do the above steps with the programming language of your choice, please
jump to the appropriate "Working with ..." in the following pages.
WORKING WITH ANY C COMPILER
(Macintosh or Windows)
instruNet provides C source code that is designed to run on virtually any C
compiler for the Macintosh and Windows.
To run the example instruNet C code, we recommend that you create a project that
supports the printf text console (not needed with Windows), C, the Operating
4-8
Ch 4 Hardware Reference
System routines, and ANSI routines. At a bear minimum, you would need
to include the following files into a project in order to run an instruNet Example:
INET_EXN.C
INET_INT.C
--ansi library
os library
console library
Contains Example#N code (use one example .c file at a time)
Contains interface to instruNet Driver
(includes files: INET_MCS.H, INET_INT.H)
Contains ANSI subroutines
Contains interface to Operating System
Supports printf() text window (only use with Macintosh)
To compile the instruNet example code and run it, you must:
1. Install the instruNet software onto your computer following the directions in
Chapter 1 Installation.
2. Make sure you have the correct version of the instruNet Driver installed on
your computer.
3. Create a new folder, called "instruNet Example", and place 2 folders inside it
called "instruNet C Source" and "End User Source". Copy (i.e. duplicate) the
following files and place them into the "instruNet C Source" folder:
INET_INT.C, INET_MCS.H, INET_INT.H, INET_EXn.C
4. Create a new project that supports the ANSI library and the console window.
5. Add INET_INT.C and INET_EXn.C to the project.
6. Compile and run.
INET_INT.C and INET_EXn.C are designed to run without a prefix file pulled in
before them (i.e. prefix option in the .... dialog). If you do have a prefix that is
automatically pulled in, you might get some compiler errors and need to debug
it a little. In general, INET_INT.C and INET_EXn.C can run with either 4 or 2
byte int's (it assumes short's are 2bytes), 8 to 12 byte doubles, different struct
packing schemes, etc. These 2 files are designed to be portable across different
processors, different operating systems, and different compilers.
The INET_INT.C file is all you need to add to your project to run instruNet. It
uses the INET_MCS.H and INET_INT.H include files. The INET_EX1.C file
contains many useful routines, yet you might not want the console to run, and
therefore you might want to modify INET_EX1.C to your own taste.
Some lines of code in the example program open the instruNet World window,
and pass control to instruNet World (until the user closes the instruNet World
window to return back to the example program). Don't let this freak you out.
4-9
Ch 4 Hardware Reference
7. Read the example program source code and comments to get a feel for
instruNet programming. Step through the source code with the debugger to see
it runs on a line-by-line basis. Read the documentation in the INET_MCS.H and
INET_INT.H include files.
Getting Started with Mac metrowerks CodeWarrior C/C++
The instruNet interface for metrowerks CodeWarrior C/C++ is compatible with
metrowerks CodeWarrior PowerPC. Recommended system requirements are a
PowerPC/G3/G4 Macintosh with 32 Meg of RAM. System 8.0 or newer are also
required.
Getting Started
instruNet can run on any version of metrowerks C greater than 7.0. To get started
with CodeWarrior C/C++, please do the following steps:
1. Make sure you have done Ch1 Installation and Ch2 Tutorial in its entirety.
2. Install metrowerks CodeWarrior onto your computer, launch the compiler, and
then run an example CodeWarrior project to verify that your C/C++ compiler is
set up properly. You can try running the "MW Hello World" project or any of
the other metrowerks supplied projects. Close the example project.
3. Create a new folder, called "instruNet CodeWarrior C Example", and place 2
folders inside it called "instruNet C Source" and "End User Source". Copy (i.e.
duplicate) the following files and place them into the "instruNet C Source"
folder:
INET_INT.C, INET_MCS.H, INET_INT.H, INET_EXn.C
4. Select New Project... from the File menu. In the Project Stationary popup,
select ANSI PPC C/C++.µ if compiling for PPC. Specify a project name (e.g.
"instruNet CodeWarrior C Example"), and then place the project into the
instruNet example folder created in step 3. After creating the project: choose
Preferences under Edit, select "PPC Project" and set the Preferred and
Minimum Heap (i.e. application file) size to 1500KB. Also, select Enable
Debugger in the Project menu to turn on source level debugging (unless you
want to use less ram at run time and do not want to step though the source code
and read the documentation).
4-10
Ch 4 Hardware Reference
PPC CodeWarrior C Project
5. Add the files INET_INT.C and INET_EXn.C to the project.
6. Select Run from the Project menu. The main()in file INET_EX1.C will first run
instruNet World. You can view and change fields and record data following
the direction in Chapter 2 Tutorial. When you quit instruNet World the
program will put you in the console window where you can read and write
individual fields. To exit the console window select Quit from the file menu.
Some lines of code open the instruNet World window, and pass control to
instruNet World (until the user closes the instruNet World window to return
back to the example program). Don't let this freak you out.
7. Read the example program source code and comments to get a feel for
instruNet programming. Step through the source code with the debugger to
see it run on a line-by-line basis. Read the documentation in the
INET_MCS.H and INET_INT.H include files.
8. Modify the Example source code to meet your own needs.
Getting Started with Microsoft Visual BASIC ≥4.0 for
Windows
Compatibility
The instruNet interface for Visual BASIC is compatible with VB Version ≥
4.x, which requires a ≥ 80386 PC / PC Compatible Computer running
Windows >= 95 and ≥8 MB Ram. A BASIC for the Macintosh is not
supported by instruNet.
Every instruNet Visual Basic program must include the .vb files in the "VB
Common Source" directory.
Getting Started
To get started with Visual BASIC ≥ 4.x, please do the following steps:
4-11
Ch 4 Hardware Reference
1. Make sure you have done Ch2 Tutorial in its entirety.
2. Install Visual BASIC onto your hard disk, load an example program,
compile, and then run to verify that your BASIC is set up properly.
3. Duplicate the "instruNet \ Programming Interfaces \ Visual Basic"
directory -- we will run/modify the files in the duplicate copy. This
directory contains the following sub-directories:
VB
VB
VB
VB
VB
Example1
Scope
Instrument
Direct To Excel
Common Source
example program #1
1 to 16 channel oscilloscope/chart recorder
2ch oscilloscope, XY recorder, Spectrum Analyzer
digitize directly to Excel Version ≥8
common source code files
4. Run one of the example programs. If you have any errors, please use the
source code to debug the system -- all source code is provided. Some lines
of code open the instruNet World window, and pass control to instruNet
World (until the user closes the instruNet World window to return back to
the example program). Don't let this freak you out.
5. Run an example program to verify that the compiler, example files, driver,
and computer are all working well together.
6. Read the example program source code and comments to get a feel for
instruNet programming.
7. Modify the Example source code to meet your own needs.
Getting Started with Microsoft C/C++ ≥ 5.0
for Windows
Compatibility
The instruNet interface for Microsoft C/C++ is compatible with C Version
≥5.0 (including Visual Studio .Net 7), which requires a ≥ 80386 PC / PC
Compatible Computer running Windows ≥ 95 and ≥8 MB Ram.
Getting Started
To get started with Microsoft C/C++, please do the following steps:
1. Make sure you have done Ch2 Tutorial in its entirety.
2. Install Microsoft C/C++ onto your hard disk, load an example program,
compile, and then run to verify that your C/C++ is set up properly.
4-12
Ch 4 Hardware Reference
3. Duplicate the "instruNet \ Programming Interfaces \ Visual C" directory -we will run/modify the files in the duplicate copy.. It contains the
following source files: Inet_int.c, Inet_int.h, Inet_Ex1.c,
Inet_Ex2.c, and iNet_mcs.h.
4. Open "Inet32_ExampleN.sln" (or ".dsp" with C version 5) with the
Microsoft Developer Studio, select Set Default Configuration under Build,
choose Win32 Debug, press OK, select Debug > Step Into under Build and
watch it compile. You should not get any compiler errors or warnings. If it
builds properly, it will begin to run under the debugger. Press the Step
Over under Debug (i.e. F10) button to step through the example program.
5. Step through the example program to verify that the compiler, example
files, driver, and computer are all working well together. Some lines of
code open the instruNet World window, and pass control to instruNet
World (until the user closes the instruNet World window to return back to
the example program). Don't let this freak you out.
6. Read the example program source code and comments to get a feel for
instruNet programming.
7. Modify the Example source code to meet your own needs.
8. If you want to operate instruNet from another C program, copy files
Inet_int.c, Inet_int.h, and iNet_mcs.h to your target project source
directory, add Inet_int.c to your project, call any of the iNet_mcs.h
macros from your own source code, call any of the Inet_int.c subroutines
from your own source code, copy any of the useful subroutines in
Inet_ExN.c into your own source code, and away you go.
4-13
Ch 4 Hardware Reference
4-14
Ch 5 Hardware Reference
Chapter 5, instruNet World
Program Reference
This chapter provides a detailed reference of the features within the instruNet
World Application Program, which is what we believe the 21st Century Strip Chart
Recorder/Oscilloscope will look like. This chapter is intended to be used as a
reference, whereas Chapter 2 Tutorial is recommended to teach the basics. To
install instruNet World, please follow the directions in the Software Installation
section of Chapter 1 Installation .
The Network Page
The Network Page is used to
view and set parameters within
an instruNet network. This
page provides a spreadsheetlike format to scroll vertically
through channels (i.e. sensors),
and horizontally through the
settings for each channel. At
any time, one can click on a
cell to open the Probe dialog,
which is used to view and
modify individual settings.
The Record Page
The Record Page is used to
Start, Stop, View in real-time,
Save to disk, and Load from
Disk waveforms. Only
channels that have been turned
"on", via the Probe dialog, are
recorded. The sample rate and
number of points digitized per
channel are specified by
pressing the Setup button. The
Trigger is specified by pressing
the Trigger button.
The Test Page
The Test Page is used to
determine what instruNet
hardware is attached to your
computer, and to test all
instruNet hardware and
software. After each test, a
report is printed to a miniature
text editor within the Test
Page. The user can then type
notes into this window, and
save it to disk as a text file.
Figure 5.1 instruNet World Pages
Overview
instruNet World is an application program that can manage, monitor and
operate an instruNet hardware network. This network can be used to digitize
long continuous waveforms, spool them to disk, view incoming waveforms in
real-time and then allow post acquisition viewing. instruNet World is included,
free of charge, with all instruNet Controller boards and does not require
5-1
Ch 5 Hardware Reference
programming experience -- it is as easy to use a simple word processor (relax
!). This chapter describes the three primary instruNet pages, as illustrated in
Figure 5.1. Each page is selected by pressing a Tab at the bottom of the
window.
Menubar Vs.
Buttons
This manual focuses on the buttons at the top of the instruNet World pages, yet
these functions can also be accessed in the menubar. For documentation on the
menubar and on instruNet World PLUS "iW+" (a version of instruNet World
with more features), please select "instruNet World+ Manual" in the "Help"
menu within instruNet World, or see Internet URL www.instrunet.com/plus.
The Network Page
Save network settings
to a preferences file
Restore network settings
from preferences file
Select Record
Page
Load network settings
from a disk file
Select Test
Page
Figure 5.2 The Network Page
5-2
Save network
settings to a disk file
Scroll through
channel settings
Clear network settings
and reset hardware
Clear network
settings
Scroll through
channel listing
Ch 5 Hardware Reference
Overview
The Network Page is used to view and modify Fields that control all Analog,
Digital, and Timer I/O channels within an instruNet network. These Fields do
things like define the cut-off frequency of a digital low pass filter, set the range of a
voltage input, or define the type of sensor that is connected to the input.
Surfing The
Net
After starting the instruNet World application the Network
Page is selected by clicking the Network tab at the bottom of
the instruNet World window. Your Network Page will resemble Figure 5.2
although your rows and columns may differ depending on what is attached to
your network.
Each row corresponds to a Channel (e.g. typically one sensor is attached to
each voltage input channel), and the columns are used to display the settings
of Fields that pertain to each Channel. The horizontal scroll bar is used to
scroll through the Fields, and the vertical scroll bar is used to scroll the
Channels.
Modifying Fields
To change a Field, simply click on its cell. The Probe dialog will pop open and it is
here that one can view and modify all Fields within the network. Typical networks
will house thousand of Fields yet their default values, in most cases, will suffice
(relax !). For a detailed description of the various settings, please refer to Chapter
8 Settings Reference of this manual.
Channels
Figure 5.3 shows an expanded view of the Network Page. The Channel names
appear in the left-most column, and the real-time values of each channel are under
"Value Input". The "network address" (i.e. network number, device number, and
module number) of each channel is shown in column 2. The first channel in the
first module of the first device attached to the first Controller will have a physical
network address of {1,1,1,1}. The table header is optimized for the upper-most
visible channel, and therefore may change slightly when scrolling vertically.
Turning A
Channel On
To "enable" a channel for digitizing (so you can see its signal in the Record Page),
one must click on the small vertical rectangle after the network address. It will
darken to indicate that the channel will be digitized when the Start button is pressed
in the Record Page. Clicking it again will turn it "off". Figure 5.3 shows Channel
"Ch1 Vin+" as being "turned On".
5-3
Ch 5 Hardware Reference
Network Number
Device Number
instruNet Channels
Module Number
Channel
Network
Name
Address
Current value of Channel
(realtime accurate)
Digitize Enabled/Disabled
Fields that describe
Channel attributes
Figure 5.3 Expanded view of the Network Page
Pull Down
Menus
Pull down menus vary depending on your operating system. For example, the
Macintosh version of instruNet World provides the minimum menus of Quit under
File; and Cut, Copy, & Paste under Edit. Control keys (e.g. Control C, or
Command C for Copy-To-Clipboard) are also supported in the Test Page's text
window.
Saving Your
Configuration
The buttons at the top of the Network Page are used to
save Field settings to disk, load them from disk, Clear them to their default values,
and to Reset hardware. In a typical session, the user will modify several Fields
(e.g. turn on 2 channels and set their filter and sensor parameters), save these
settings to disk via the Save button, exit instruNet World, run instruNet World a
week later, and reload these settings via the Open button. When the state of
instruNet World is saved to disk, you are saving the Fields that have changed from
their default values. When you load the state back in, instruNet will first set all
Fields to their default values, load the file, and then update the Fields that were
changed. -- therefore, these "state" files are typically small (e.g. several KB). In
fact, you can open these text files with a Word Processor or Spreadsheet program
to glean a sense as to how instruNet internally stores Fields settings. instruNet
keeps all state in Fields, therefore, it is not necessary to save anything else (except
waveform data) in order to get you back to where you were. Saving waveform data
is done independently via the Save and Open buttons at the top of the Record Page.
The Network Page manages Fields, whereas the Record Page manages waveforms.
Reconnecting
With A Changed
Network
If your instruNet Network changes (e.g. you physically pull out 1 device, and then
install 2 more), the stored Field settings may no longer apply to your new network.
instruNet does its best to "reconnect" and will alert you to any discrepancies, yet it
is always a good idea check your settings after physically changing your network.
Typically, adding hardware will not cause discrepancies, since you are adding
Fields that will be kept at their default values when you load in the settings to
"other" fields. However, if you physically reduce your instruNet network (or
replace one device with another), a settings file may try to set a field that no longer
5-4
Ch 5 Hardware Reference
exist, and in this case, instruNet might show an alert that states it is having a little
trouble.
Buttons
The Network Page has the following buttons at the top of the window:
Restores the state of all Fields that existed when the Store button was last pressed.
Restore loads a .prf settings file that is kept in an operating system preferences
directory. You must press Store to save this file before you press Restore.
Restore and Store are very similar to Open & Save, except Open & Save show a
File dialog that enables the user to pick the file name & directory; whereas
Restore & Store always go to the same file & directory and do not bother the user
with file issues.
Saves an instrument setup .prf file to disk that contains the state of all Fields. This
preferences file is stored within the operating system directory, and is reloaded by
pressing the Restore button. File Save and File Open dialogs are not used since the
file name and directory are always the same.
Saves a .prf instrument setup file to disk that contains the state of all Fields,
scripts, and user defined objects. The user specifies the file name and location
within the standard File Save dialog.
Loads a .prf instrument setup file from disk that contains the state of all Fields,
scripts, and user defined objects. The user must pick a previously stored settings
file via the standard File Open dialog.
Delete channel settings, scripts, and user defined objects (e.g. popup menu, edit
field, etc).
Same as the Clear button, yet also Resets all instruNet hardware.
Calibrates all instruNet hardware. To set up this button to also balance strain
gages and load cells at 0 uStrain (or 0 Kg force), press the Setup button in the
Record page, press the Calibration button, set the Cal Btn field to Bal Gages, and
then exit the dialogs. For more details on Calibration options, please Application
Note #67.
5-5
Ch 5 Hardware Reference
The Record Page
The Record Page is used to view recorded (i.e. digitized) waveforms in real-time,
store these waves to disk, load them from disk, and scroll through them post
acquisition. The Record page, illustrated below, is chosen by pressing the Record
tab at the base of the instruNet World window.
Start recording
Select Network
Page
Save waves to disk
Stop recording
View & edit
Load waves
Setup options
from disk
Select Test
Page
Scroll through
acquired data
Click here to
change
channels
parameters
Channel Channel realname
time value
Figure 5.4 The Record Page
Setting Up
Channels
A display is shown for each Channel that has previously been turned On. For
example, in Figure 5.4, one channel (i.e. "Ch1 Vin+") has been turned On. To
learn how to turn Channels On and Off, please consult the "Turning A Channel On"
discussion earlier in this chapter. The horizontal scroll bar is used to horizontally
scroll through waveforms, post-acquisition, and consequently sets the time of the
left edge for all displays. The minimum display height is about 2cm, therefore if
more displays exist than there is room, only a subset will be shown, and the user
can vertically scroll through the viewed subset with the vertical scroll bar.
Setting Up
Displays
To adjust the engineering units value that corresponds to the top
and bottom of each display, click on its label (pictured to the left)
5-6
Ch 5 Hardware Reference
at the display right edge. The Display dialog will open, as illustrated below.
Turn display On/Off
If “On”, the channel is digitized (and
displayed, if the Record page is open)
when the START button is pressed;
otherwise, it is dormant while Digitizing.
This corresponds to the vertical axis
value, in engineering units, at the top of a
Display.
This corresponds to the vertical axis
value, in engineering units, at the bottom
of a Display.
Figure 5.5 Display settings
Oscilloscope
or Strip Chart
Scan Mode
instruNet supports two Scan Modes, Oscilloscope and Strip Chart, one of which is
selected in the Scan Mode popup within the Setup Dialog. Oscilloscope digitizes
individual Scans (similar to a real Oscilloscope), whereas Strip Chart links a set of
scans together, seamlessly, to form one long waveform (the user does not notice the
individual Scans), as illustrated in Figures 5.6 and 5.7. Put a little differently,
Oscilloscope waits for a Trigger (specified in the Trigger dialog) before digitizing
each Scan, and Strip Chart only waits for a Trigger before digitizing the first Scan.
Trigger
wait for trigger
digitize Scan n
time = 0
Start button pressed
time
digitize Scan n+1
digitize Scan n+2
Figure 5.6 Strip Chart Recorder Mode
Trigger
Trigger
wait for trigger
digitize Scan n
time = 0
Start button pressed
wait for trigger
digitize Scan n+1
time = 0
time
Figure 5.7 Oscilloscope Mode
5-7
Ch 5 Hardware Reference
Oscilloscope mode has two variations, Oscilloscope and Oscillo Queued. Both
Oscilloscope and Oscillo Queued acquire and store scans of data in a buffer for
processing. In Oscilloscope mode the most recent scan of data in the buffer
will always be returned for processing (first in, last out). In Oscillo Queued
mode the scans are retrieved from the buffer in sequence (first in, first out).
A typical example of how a data acquisition program using Oscilloscope mode
would work is as follows: first the program would wait for the user specified
trigger condition and then acquire the first scan of data; next the program would
process the acquired scan (i.e. display, analyze, save to disk) while instruNet
continued to acquire scans in the background based on the trigger condition,
while the processing is going on; next the program would retrieve the most
recent scan from the queue, ignoring older scans.
In the Oscilloscope case the scan returned from the buffer will always be the
most recently acquired scan, and all other scans in the buffer will be ignored.
For example if each scan were 10ms long, the trigger condition was set to none,
and the processing took 40ms, then the program would retrieve the first scan,
process it and then retrieve the 4th of the 4 queued scans (i.e. the most recent
scan) that had accumulated in the buffer while it was processing the first scan.
The 3 other older scans would be discarded.
If the example above were done in Oscillo Queued it would work as follows:
first the program would wait for the user specified trigger condition and then
acquire the first scan of data; next the program would process the acquired scan
(i.e. display, analyze, save to disk) while instruNet continued to acquire scans
in the background based on the trigger condition; next the program would
retrieve the next scan in the queue (i.e. the acquired scan that immediately
followed the first acquired and processed scan). In Oscillo Queued mode
triggered scans continue to accumulate in the queue and are returned in order.
In Oscillo Queued mode all scans are returned by instruNet for processing but
if a lot of processing is required between scans the instruNet buffer can
eventually overflow at which point instruNet will return an error message. In
Oscilloscope mode the most recent scan is always returned and others are
discarded. While scans are discarded in Oscilloscope mode the buffer will not
overflow. If the time to process data takes less than the time of a scan then
both modes will behave identically. Figure 5.8 below shows the difference
between Oscilloscope and Oscillo Queued modes.
5-8
Ch 5 Hardware Reference
Oscillo Queued
Scans
Internal data buffer
of acquired data
1
2
3
4
All Scans Retreived
for Processing
1
2
3
4
5
6
Oscilloscope
1
Most Recent Scan
Retreived for
Processing
1
8
9 10 11 12 13 14
data processing occurs here
scans not
retreived
Internal data buffer
of acquired data
7
2
3
4
scans not
retreived
5
6
7
8
5
scans not
retreived
9 10 11 12 13 14
9
13
Figure 5.8 Oscilloscope and Oscillo Queued Modes
5-9
Ch 5 Hardware Reference
Figure 5.8b The Record Setup Dialog
Record Setup
The Record Setup dialog, illustrated in Figure 5.8b, is used to set the base
sample rate, the number of points to be acquired per Scan, the number of Scans
to be acquired, the recording mode (i.e. oscilloscope or strip chart recorder), the
storage mode, and the display mode. This dialog is described in detail in
Chapter 2, Digitizing Analog Signals into the Computer.
Timing Options
The Timing dialog, illustrated in Figure 5.8a, is used to
set Fields that determine the digitization length and
method. This dialog is opened by pressing the Timing button inside the Setup
dialog, and mirrors some of the settings inside the Setup dialog.
Number of samples
Digitized in one
second, for each
channel
Number of scans digitized
when Start button is pressed
Network data
transfer rate
(bits-per-second)
Select continuous or noncontinuous recording mode
Channel
switching speed
Number of points in each scan
(each scan is a set of points)
Figure 5.8a Timing Dialog
The Pts per Scan, and the No. of Scans Fields specify the number of points (4bytes
per point) that are digitized for each Scan, and the number of scans that are
digitized when the Start button is pressed. For example, if you digitize 100
pts/second, with 1000 points per Scan (i.e. 10sec per scan), and 10 scans, then your
entire acquisition would consume 100seconds. Pressing the Stop button will halt
the digitization process, independent of where it is in its cycle. The Scan Mode
field was discussed in detail in the previous Strip Chart or Oscilloscope Scan Mode
discussion.
The Sample Rate fields specifies the number of points digitized per second per
channel. All channels run at this rate unless their % Sample Rate Field in their
General settings area has been modified from its default value of 100%. This field
enables one to run specific channels at a sample rate less than the master sample
rate in the Timing dialog. For example, if the master sample rate is 1000s/sec and
a channel's % Sample Rate is set to 25, then the channel will run at 250s/sec. The
5-10
Ch 5 Hardware Reference
Network BPS specifies the network data transfer rate, in units of bits-per-second.
On power up, the network is set to the fastest possible rate. The Switching popup
is sets the analog channel switching to Fast or Accurate. If Fast is used, the system
switches from one channel to another as fast as possible; otherwise, with Accurate,
the switching is a little slower, yet provides the amplifiers more time to settle, and
is therefore a little more accurate.
Calibrate
Options
The Fields in the Calibration Options dialog are used to
specify Calibration parameters, as illustrated in Figure
5.8b. This dialog is opened by pressing the Calibration button, inside the Setup
Dialog.
Figure 5.8b Calibrate Options
The Cal Button popup controls the function of the Calibration button in the
Network page. It is set to one of:
a. Measurement - instruNet hardware is calibrated when the Network Calibrate
button is pressed.
b. Bal Gages - instruNet hardware is calibrated and all strain gages & load cells
are balanced when the Network Calibrate button is pressed.
c. Bal Bridges - instruNet hardware is calibrated and all bridges (e.g. strain gages,
load cells, potentiometers) are balanced when the Network Calibrate button is
pressed.
d. Bal VDividers - instruNet hardware is calibrated and all voltage dividers are
balanced when the Network Calibrate button is pressed.
"Balancing" involves reading the voltage across a sensor and placing it into the
"Vinit" field within the Constants settings area. This is done to establish a zero
point from the sensor, and should be done when the sensor is not receiving a
stimulus.
If Cal On Digi is set to On, the instruNet hardware is automatically calibrated when
the user presses the Start button and begins to digitize.
If Cal On Warm is set to On, the instruNet hardware is automatically calibrated
10minutes and 25minutes after the instruNet software is first run.
The Auto Cal Rate field sets the rate that instruNet measurement electronics is
automatically calibrated, in units of minutes. A full calibration occurs if not
5-11
Ch 5 Hardware Reference
digitizing, and a less intensive thermal drift only calibration, described below,
occur if digitizing. For example, if this field is set to 5, then instruNet hardware is
automatically calibrated every 5 minutes. If set to 0, the Auto-Calibrate feature is
disabled. The minimum rate is 0.016 minutes. The primary error from the
measurement electronics is an offset voltage of approximately 2uV/C that occurs at
the analog voltage measurement input amplifier. This means you will get an offset
error of approximately 2uV for every 1 degree C that the amplifier IC heats up. It
heats approx 5C above ambient (air around instruNet box) when first turned on and
stabilizes after 1hr or so. From here, the IC temperature changes as the room
temperature changes (e.g. a 5C increase in room temperature will increase the IC
temperature by 5C, which could add voltage measurement offset error of 10uV).
When Auto Cal is run, this error is eliminated to 0uV. During digitizing, an
abbreviated version of auto-calibration takes place, as described below.
Auto-Calibration While Digitizing
instruNet can automatically calibrate out thermal offset drift errors (e.g. 2uV offset
error per 1C change in i100 box temperature) while digitizing (requires iNet32.dll
>= 1.40.1.1). These errors are proportional to the temperature change since the last
auto-calibration. For example, if we calibrate the i100 at 25C (i100 box
temperature), and later the box temperature is 29C, then the Voltage inputs will
produce measurement errors between -8uV and +8uV (2uV/C * 4C = 8uV). In
many cases; this is not a problem; yet with strain gages, load cells and
thermocouples; this could be an issue. In order for this auto-calibration of thermal
offset errors (to zero error) while digitizing to operate, all the 40/4KHz analog
filters must be off on all channels within the i100xx box being calibrated; and,
there must be at least 6ms of time between the total integration time and the sample
period. For example, if one digitizes 4 channels with 4ms integration each (16ms
total), they would need a sample period of at least 20ms to support this feature. To
see which channels are set up for auto-calibrate offset drift while digitizing, set up
your recording, press the START button to digitize for several seconds, press
STOP, enter "calibrate reportOn" in the BASIC page, press EXECUTE, and view
the listed channels. If your list is empty, make sure your AUTO CAL RATE field
is >0, make sure all 40/4KHz filters are off, and make sure at least one channel has
a range <= +-80mV (large ranges are not affected.
The Cjc Cal Rate field sets the rate that instruNet hardware automatically reads the
temperature of the cold junction compensation sensor, in units of minutes, which is
used for thermocouple measurements. If set to 0, this feature is disabled. The
minimum rate is .016minutes. Reading the cjc sensor can occur while digitizing at
slow <1KHs/sec speeds and when the sum of the integration time is less than 40%
of the sample period. If the iNet hardware reads the screw temperature (i.e. does a
CJC calibrate), and the screw then drifts by X degrees before the next CJC cal, one
will incur a thermcouple measurement error by that amount (since the software
subtracts the screw terminal temperature when calculating the thermocouple
temperature).
5-12
Ch 5 Hardware Reference
For information on how to calibrate while digitizing, how to enable a beep when
calibration occurs, and how to minimize thermocouple drift errors, please see
Application Note #67.
Display
Options
The Fields in the Display Options dialog are used to specify Display attributes,
as illustrated in Figure 5.9. This dialog is opened by pressing the Record button,
inside the Setup Dialog, and mirrors some of the settings within the Setup dialog.
Horizontal Scale in Record page Displays
(seconds per horizontal division)
Plot Dots or
Lines in Displays
Turn Display
Grid On or Off
Horizontal starting position in Record page
Displays (display left edge, in seconds)
Maximum points plotted
per horizontal pixel in
Record page Displays
Figure 5.9 Display Options
Specify where digitized data
is stored (no where, RAM,
or Disk File)
It is in the Options dialog that one specifies to Plot Dots or Lines, to turn the Grid
On or Off, to set the horizontal scale (i.e. time per horizontal division), and to set
the maximum plotting density (maximum points plotted per horizontal pixel).
Plotting Lines (i.e. connecting points with lines) takes more time than Dots, yet is
easier to read if the points are far apart. The Grid take some time to plot as well,
and might not be desirable if you are trying to maximize your update rate in
Oscilloscope mode. If the horizontal scale (Horiz Scale) is too small (e.g.
10ms/div), the waveform might whip across the screen and be difficult to see in the
Strip Chart mode. The maximum points per horizontal pixel (Max Pts/Pix)
parameter is useful at plotting only a fraction of the digitized points in cases where
you are digitizing ten's of thousands of points and don't want the computer to slow
down due to plotting. The Horizontal Position (Horiz Pos) field is very similar to
the Horizontal scroll bar in that it defines the time of the left edge of all displays.
If Overflow Alert is set to On, an Alert box is shown when a digitize buffer
overflows (i.e. it fills faster than it is read); otherwise digitizing proceeds without
an Alert.
Saving Data
The Digitize Into option in the Display Options dialog is used to determine whether
5-13
Ch 5 Hardware Reference
waveform data is saved to To Ram Buffer, saved to To File, not saved (Off), or
determined by the user (User Control). For information on how to save a text
file to Excel, post-acquisition, please refer to Appendix III.
Off
If the user selects Off, the waveforms are viewed while they are digitized, however
you cannot scroll through them post acquisition (since the computer had not saved
the data). Since this does not consume memory or disk space, one could digitize
many waves at a fast rate for a long time.
To Ram Buffer
If one selects To Ram Buffer, each Scan is sent to RAM memory, which is limited
by the amount of RAM that has been allocated to the instruNet World application
program (or the calling application program in the case of calling the instruNet
driver). The buffer in memory holds only one Scan's worth of points, and therefore
overwrites the previous Scan with each subsequent Scan. If you are doing Strip
Chart work and don't like this, set the No. of Scans field in the Timing dialog to 1,
and the Pts Per Scan field to the value required to hold the entire acquisition. If
you run out of RAM memory on a Macintosh, you should consider giving your
application more by selecting the Application Icon from the Finder, choosing Get
Info under File, and then increasing the number in the memory "Minimum Size"
field. Each point consumes 4 bytes since they are stored as 32 bit floating point
numbers. For example, 100K points would consume 400KBytes. If you have just
completed an acquisition with data being sent to RAM and want to save it to disk,
press the Save button at the top of the Record page. This will save all waves to
disk. You can then load the waves by pressing the Open button.
To File
If you want to save all scans to disk, set the Digitize Into option to To File. This
will cause all waves to be spooled to disk as they are acquired. If you are doing
Strip Chart work, you can then use the horizontal scroll bar to scroll through the
entire stream of data. To load in data that was previously saved to disk, press the
Open button and then select a previously saved wave in the File Open dialog.
Saving to disk is helpful if your waveforms are longer than available RAM.
User Control
If User Control is selected in the Digitize Into field, then data will be saved per the
settings in the User Ram Buffer, Driver Ram Buffer, and File Settings areas -which are described later in this manual.
Trigger Options
5-14
The Trigger dialog is accessed by pressing the Trigger button within the Setup
dialog. This dialog is used to specify when digitizing begins after the Start button
is pressed, as illustrated in Figure 5.10.
Ch 5 Hardware Reference
Set Trigger On or Off
Trigger when signal passes this threshold
value, in engineering units
0
Trigger from a Rising or
Falling edge signal
Duration, in seconds, to digitize
before the trigger event occurs
Network address of the
Trigger Source
Figure 5.10 Trigger options
The Trigger field is used to specify no trigger (Off), Automatic trigger, or Normal
trigger. Normal trigger will wait forever until the trigger condition is met, whereas
Automatic will trigger after several seconds even if the trigger condition is not met.
The Threshold EU field is used to set the threshold level, in engineering units, that
the incoming signal must pass in order to trigger. The Slope field sets the trigger
condition for either a low-to-high pass through the threshold (Rising), or a high-tolow (Falling). The Network number, Device number, Module number, and
Channel number fields are used to specify the network address of the input channel
that is to be used as the trigger source. For example, {1,1,1,1} would specify the
first channel within the first module in the first device tied to the first network.
Getting Ready
to Digitize
Before you digitize, you might want to view the settings in the Setup dialog
box, which is opened by pressing the Setup button at the top of the Record page.
This dialog's fields are described in detail in the previous pages. In summary, one
must specify the number of samples digitized per second per channel (i.e. "sample
rate"), the number of points per scan, the number of scans, and weather or not the
scans are continuous (i.e. Oscilloscope or Strip Chart Recorder mode). The Trigger
dialog is used to define when the digitizing begins (e.g. begin when the voltage at
Channel #1 exceeds 3Volts). In many cases, there is no Trigger, and the
digitization begins when the Start button is pressed.
Digitizing
To begin digitizing, press the Start button in the upper-left corner.
Waveforms will plot across the screen, in real-time, as they are
digitized. To stop digitizing, press the Stop button. If the waves had been saved to
Ram or Disk (i.e. via the Digitize Into field in Options dialog), then you should be
able to scroll through your data with the Horizontal scroll bar.
If Your Sample
If the sample rate is too fast, an alert will appear notifying the user to a buffer
5-15
Ch 5 Hardware Reference
Rate Is
Too Fast...
overflow or sample rate problem. This means the computer and/or Controller
cannot keep up with the incoming data. In this case, you have several options:
1.
2.
3.
4.
Record Buttons
Reduce the master sample rate (i.e. Sample Rate field in Setup dialog), or the
number of digitized channels.
Decrease the % Sample Rate field in a Channel's General settings area to
decrease the sample rate for that specific channel. For example, if you run 1
channel at 10% of the master sample rate, then its sample rate will be 1/10 of
that of the other channels.
Decrease the amount of plotting by reducing the size of the instruNet World
window, plotting Dots instead of Lines (i.e. set the Plots field to Dots in the
Options dialog), or reducing the plotting density by decrease the Max Pts/Pix
field in the Options dialog.
Reduce the amount of digital filtering in the Low Pass, High Pass, Band Pass
and Band Stop settings areas. Digital filters consume several microseconds to
.1us per Filter Order, per point digitized.
The Record Page sports the following buttons:
Start digitizing channels that have been turned On. Each channel is viewed in its
own display. The Digitize Into field in the Setup Dialog determines whether data
is saved to RAM or Disk.
Stop digitizing. If the data had been saved to Ram, then one can now scroll
through the most recent Scan, or save the Scan to disk by pressing the Save
button. If the data had been saved to Disk in Strip Chart mode, the user can now
scroll through the entire set of Scans via the horizontal scroll bar.
The Open button loads waveforms to disk that had been previously saved to disk
during acquisition, or by the Save button after acquisition had completed. The
standard File Open dialog is used to select the specific wave file. Since waves are
saved in their own file, in one directory, it is necessary to only select one file, in
order to load the entire set. Once loaded, one can use the horizontal scroll bar to
scroll through them.
Saves to disk the current Scan in RAM memory. The user is prompted for a
directory name in which to save the set of data, where each wave is saved in its
own file, in one common directory. The data is saved in the fast instruNet Binary
Merge format, multi-file Binary format, or slow generic text format as determined
by the File Type field in the Digitizer Channel, within the Driver . If Text Merge
is selected in the File Type popup, an additional "Excel Waveform Data.txt" text
file is saved that contains all waves in one file, one column of text per wave. This
is useful when transferring data to a spreadsheet. Binary Merge saves to disk
faster than Binary, yet consumes more RAM memory.
Opens the Record Setup dialog, as described in the previous pages.
5-16
Ch 5 Hardware Reference
Prints the recorded waveforms to a hard copy printer, at the horizontal scale
specified in the Record Setup dialog (i.e. which is mirrored at the front panel
horizontal scale popup menu). Multiple pages are printed, as required. For
example, if the waves are 100 seconds long, the horizontal scale is set to
1sec/division, and the paper is 20 divisions wide (each grid division is
approximately 1 x 1 cm), then 5 pages will be printed. If the horizontal scale is
set to AUTO, the entire digitization is printed on one page. Printing requires
instruNet World PLUS (iW+).
Test Page
The Test Page, illustrated in Figure 5.12, is used to determine what instruNet
hardware is attached to your computer, and to test all instruNet hardware and
software. After each test, a report is printed to a miniature text editor within the
Test Page. The user can then type notes into this window and save them to disk
as a text file, to later be opened with the Open button in the Test Page, or a
word processor. The Test Page supports the standard text Cut, Copy, and Paste
commands, in addition to typing (i.e. Control X, C, and V in Windows). To
select the Test Page, press the Test tab at the base of the instruNet World
window.
5-17
Ch 5 Hardware Reference
Test all ioNet
hardware
Print list of installed
ioNet hardware
Repetitively test all
ioNet hardware
Load text file
from disk
Clear text
in window
Save text window
contents to disk
End user
notes
Search
results
Test
results
Select Network
Page
Select Record
Page
Text editor
window
Scroll through text
editor window
Figure 5.12 instruNet World Test Page
Test Buttons
The Test page sports the following buttons:
Generates a report, similar to that below, that lists all instruNet hardware attached
to your computer. This includes all Controllers and all Devices. If this report
disagrees with what you think is out there, please check your cables and consult
the "Verify That Your System Is Working Properly" discussion in Chapter 1.
INSTRUNET HARDWARE SEARCH RESULTS:
Date & Time: 10/23/1995, 19:23:20
Net Dev Mod Device
---------------------------------------0
0
0 Windows XP Version 5.1.2600
0
0
1
instruNet Driver (DLL 1.36.4, PCI 1.3)
0
0
1
instruNet World+ license 32-048353-62581
1
0
1
PCI Controller #iNet-200 (slot #13, 2666KBD, 7us, 95%)
1
1
1
Device #iNet-100 (SN37526, Cal 8/27/1997, Rev 3, 27.52C, 7us, 4mA)
5-18
Ch 5 Hardware Reference
Click the Test button to test
all Controllers, Devices,
Modules, Channels, and
software. This test requires
less than a minute and when
done displays an alert
similar to that shown to the
right. A report similar to that shown below is also printed to the Test Page's
text window. For a list of the error codes please consult Appendix II instruNet
Error Codes. For tips on trouble shooting, please consult Appendix I.
INSTRUNET QUICK TEST RESULTS:
Date & Time: 11/8/1995, 17:17: 1
We ran 0.542568 million tests and did NOT hit 1 error.
Big Test is identical to Test except it runs continuously until you press the mouse
button down and hold it down until the test stops. It will run all night if you let it.
This is helpful at identifying intermittent problems that occur once in a blue
moon.
Loads a text file into the Test page's text editor.
Saves the contents of the Test page's text editor to disk in a text file.
Discards the text in the Test Page's text editor.
Prints an internal diagnostic report to be emailed to your instruNet supplier for
comment when debugging. After pressing this button, copy the text to the
clipboard (Windows Control C), paste it into an email window (Windows Control
V), and email to your supplier. A Diagnostic Report can also be generated by
pressing the "SAVE DEBUG REPORT TO DISK" button within an error alert.
For details, please see Application Notes #69 and #121.
Prints the Test page text to a hard copy printer. Requires instruNet World PLUS
(iW+).
The Script Page
To learn more about the iW+ Script page, please select "instruNet World+ Manual"
in the "Help" menu within instruNet World, or see Internet URL
www.instrunet.com/plus.
Menubar Reference
5-19
Ch 5 Hardware Reference
This manual focuses on the buttons at the top of the instruNet World pages, yet
these functions can also be accessed in the menubar. For documentation on the
menubar and on instruNet World PLUS "iW+" (a version of instruNet World
with more features), please select "instruNet World+ Manual" in the "Help"
menu within instruNet World, or see Internet URL www.instrunet.com/plus.
5-20
Ch 6 Hardware Reference
Chapter 6,
Reference
Hardware
This chapter includes specifications for the following instruNet hardware products:
instruNet Controllers
• Model 200 instruNet Controller for Windows 95/98/Me/Nt/2k/Xp PCI bus or
Macintosh/PCI bus
• Model 230 instruNet Controller for Windows 95/98/Me/2k/Xp (not NT) PCCard bus (16bit PCMCIA)
instruNet Network Devices
• Model 100, 100B, and 100HC Analog/Digital I/O Network Device
instruNet Network Accessories
• Model 300 Power Adaptor
• Model 311.x, 312.x, 322.x Power Supplies
• Model 330 Electrical Isolator
6-1
Ch 6 Hardware Reference
Model 200 PCI instruNet Controllers
The Model 200 instruNet Controller boards attach to personal computers via an
expansion slot to drive an instruNet network, and to provide several Digital Timer
I/O channels at a 34-pin connector, as illustrated in Figure 6.1a. Table 6.1
describes the pins at the Controller 34-pin connector.
Device #2
Digital I/O Connector
(34pin male header,
.1”grid, .025” posts)
+5V
restricted
+12V
restricted
-12V
Ch10 Dout
Ch9 Dout
Ch8 Dout
Ch7 Dout
Ch6 Dout
Ch5 Dout
Ch4 Dout
Ch3 Dout
Ch2 Dout
Ch1 Dout
Gnd
Gnd
34
32
30
28
26
24
22
20
18
16
14
12
10
8
6
4
2
33
31
29
27
25
23
21
19
17
15
13
11
9
7
5
3
1
+5V
restricted
+12V
restricted
-12V
Ch10 Din
Ch9 Din
Ch8 Din
Ch7 Din
Ch6 Din
Ch5 Din
Ch4 Din
Ch3 Din
Ch2 Din
Ch1 Din
Gnd
Gnd
Device #1
DB-25 cable
Terminator
34
2
33
1
32-bit µProcessor
Ram Buffer
Model 200: PCI Bus connector
ioNet Network Connector
Model 230: PC-Card Bus connector
(DB-25 female)
Model 220: Nubus connector
Fig 6.1a Model 200 instruNet Controller Connector Layouts.
Specifications
The physical specifications for the Model 200 Controllers are as follows:
Digital I/O Connector:
Network Connector:
Network Data Throughput:
Dimensions:
Operating Temperature Range:
Storage Temperature Range:
Relative Humidity:
Power Consumption:
(does not include network)
6-2
34-pin male ribbon connector*
DB-25 female connector
100Kbits/sec to 4,000Kbits/sec
4" x 7"
0 to 70˚C
-25 to +85˚C
Up to 90% (non-condensing)
+5V @ 1A max
+12V @ 10mA max
-12V @ 10mA max
Ch 6 Hardware Reference
Controller 34-pin Connector
I/O Terminals
Ch1..10 Din
The {Ch1 Din...Ch10 Din} digital input terminals
are used to sense a digital high or digital low state; or
to measure the period of a changing digital signal.
The inputs are protected against high voltages up to
+6Volts and down to -6V. To measure the logic
level or the period of an input signal, connect it
directly to a Controller Din terminal and then
connect the signal source ground to a Controller Gnd
terminal. For details, please see Ch2, Working with
Controller Digital Timer I/O Channels.
Specifications (typical at 25°C)
Digital Inputs
Digital Input Port
Input Levels
Period Measurement
Measured Period Range
Resolution
Ch1..10 Dout
Digital Outputs
Digital Output Port
The {Ch1 Dout...Ch10 Dout} digital output terminals Logic
can be set to a high or low state; or set up to output a Output Levels
digital clock signal. To wire a Dout terminal to a
device, connect the Dout terminal to the device input,
and the Controller Gnd terminal to the device Ground.
For details, please see Ch2, Working with Controller
Clock Outputs
Digital Timer I/O Channels.
Duty Cycle Range
Period Range
Time Base Accuracy
Output Signal
+5V, -12V, +12V
1 non-latching input bit per
channel
VIH = 3.5V min ... 6V max
VIL = .75V max ... -6V min
IIH = -120µA, Vi = 3.5V
IIL = -.6mA max.
VHYSTERESIS = .5V
1Cycle: 3us-16ms ± .25us
or 3ms-32sec ± 1ms
>1Cycle: 3us - 4.1sec ± .25us
or 3ms-16Ksec ±1ms
1Cycle: 16bits
>1Cycle: 24bits
1 latching output bit per
channel
TTL-compatible
VOH = 2V min ... 5V max
VOL = 0.5V max ... 0V min
IOH = -12mA max.
IOL = 24mA max.
.01% to 100%
5µsec to 536 sec
(programmable)
+- 0.01%
TTL Compatible
Power Available to User
+5V
These terminals can be used to power external devices. The
+12V
maximum allowed current, listed to the right, must not be
-12V
exceeded; otherwise damage might occur to the Controller or
computer. To power an external device, one must attach a wire
from one of the Controller power terminals to the external
device's power input, and also attach a wire from the Controller's
Gnd terminal to the external device ground.
300 mA max.
50 mA max.
50 mA max.
Table 6.1 Model 200 Controller 34-pin Connector Technical Specifications .
*The Model 230 PC-Card Controller does not include the 34-Pin Digital I/O Connectors, and its signals.
6-3
Ch 6 Hardware Reference
Model 230 PC-Card instruNet Controller
The Model 230 PC-Card (16bit PCMCIA) instruNet Controller attaches to a
personal computer via a 16bit PC-Card slot to drive an instruNet network, as
illustrated in Figure 6.2. The i230 has the same capabilities as the i200 PCI
controller, except it requires an external power supply (e.g. iNet-312-8), it does not
provide 10 counter/timer channels, and it is not compatible with Windows NT.
Device #2
Device #1
DB-25 cable
Terminator
instruNet
instruNet Network Controller #iNet-230
16bit 2.1 Compliant PC-Card, 5V .5A, .5MB Memory Space
Part 15 FCC Class A and CE Compliant.
instruNet Network
Connector (DB-25 female)
instruNet Network
Power Input Connector
(5pin DIN female)
Fig 6.1b Model 230 instruNet Controller .
Specifications
The physical specifications for the Model 230 Controller is as follows:
Network Connector:
Network Power Input Connector:
Network Data Throughput:
Dimensions:
Temperature Range:
Relative Humidity:
Power Consumption:
6-4
DB-25 female connector
5pin DIN female connector
100Kbits/sec to 4,000Kbits/sec
2.1" x 3.4"
Operating 0 to 70˚C, Storage -25 to +85˚C
Up to 90% (non-condensing)
+5V @ .5A max
Ch 6 Hardware Reference
Model 100, 100B, and 100HC Network Devices
Slide .187” x .067” 4-40 hex
nut (small format nut) into
groove to mount enclosure
Power
available to
user
Ch 25 Digital I/O
6
Vout
Vin (-)
Vin (+)
Ch 22 23 24
GND
Vin (-)
Vin (+)
Vout
GND
2 3 Ch 4 5
Vin (-)
Vin (+)
GND
DIO7
DIO8
DIO5
DIO6
Ch25 DIGITAL I/O Ch 1
DIO3
DIO4
DIO1
DIO2
+5V
GND
-12V
+12V
ioNet Model 100
Vout
Ne
tw
Ne ork
tw In
ork
Ou
t
Units stack via mating
top /bottom rails
Ch 1...24 Voltage
Inputs & Voltage
Outputs
Fig 6.2 Model 100xx Network Device Connector Layout.
Model 100xx Connector
I/O Terminals
Ch 25 Digital I/O
This is a digital I/O port consisting of 8 individual
lines, each of which can be configured as either a
digital input channel or a digital output channel.
When configured as an input, a channel can be used
to sense a digital high (3.2V to 10Volts) or digital
low (0 to 1Volts). When configured as an output a
channel can be set high (2.0V min) or low (.5V
max). The inputs are protected against high voltages
up to and +12Volts and down to -12V.
Specifications1
Digital I/O
Digital Input/Output
8 non-latching input bits and
8 latching output bits at 8
bidirectional screw terminals
Input Levels
VIH = 3.2V min ... 12V max
VIL = 1.0V max ... -12V min
IIH = -200µA, Vi = 3.2V
IIL = -.5mA max.
Output Levels
VOH = 2V min ... 5V max
IOH = -.5mA max.
IOL = 500mA max, VO=1.7V
IOL = 50mA max, VO = .7V
Table 6.2 Model 100, 100B, and 100HC Technical Specificati
6-5
Ch 6 Hardware Reference
Model 100xx Connector
I/O Terminals
Ch 1...24 Vin+/Vin-
These are voltage input ports that can be wired for
any of the sensors described in Chapter 5 Sensor
Reference. When wiring single-ended inputs the
Vin+ and Vin- terminals function identically.
Specifications1
Analog Inputs
A/D Conversion Time
A/D Resolution
Voltage Input Range
4µs min
14-bit
+- 5V
+-.6V
+- 78mV max, +- 80mV typ
+- 8mV max, +- 10mV typ
Amplifier Gain
Number of Channels
System Throughput
1, 8, 64, 512
16se/8di
166Ksamples/second max
Measurement Accuracy
Voltage
Range
±5V
Integration
(seconds)
1ms
0sec
0sec
Channel
Switching
(either)
Accurate
Fast
Voltage
Accuracy
±.75mV
±1.5mV
±2.5mV
±0.6V
1ms
0sec
0sec
(either)
Accurate
Fast
±75µV
±150µV
±225µV
±80mV
1ms
0sec
0sec
(either)
Accurate
Fast
±15µV
±45µV
±60µV
±10mV
1ms
0sec
0sec
(either)
Accurate
Fast
±10µV
±30uV
±50µV
Signal To Noise Ratio
Differential Linearity
Integral Linearity
Ch 1...24 Vout
These are voltage output ports that can be used for
purposes such as stimuli and sensor excitation.
78dB
+- 1.5 LSB
+- 2 LSB
Input Over voltage Protection +- 15 V (power on or off)
Input Impedance
10MΩ ±1%, 3pf
Common Mode Voltage (CMV)
+- 5V min.
Common Mode Rejection (CMR)
+- 80dB
Temperature Drift
Gain: +- 5ppm/˚C of FSR
Offset: Self-cal'ed to 0
Time Stability
Gain: 27ppm/1yr typ
Offset: Self-cal'ed to 0
Analog Outputs
D/A Resolution
8-bit
Number of Channels
8
#100/100B: ±5V, 4mA, .001uF
Output Voltage Range
Output Protection
Output Settling Time
Analog Output Accuracy
Digital Coupling
Gain Drift
Offset Drift
#100HC: ±5V, 15mA, .01uF
Short-to-ground continuous
4µs (to +-1/2 LSB,+-5V step)
+-0.4%
+-20mV
+- 10ppm/˚C of 5V FSR
+- 5µV/˚C
Table 6.2 Model 100, 100B, and 100HC Technical Specifications.
6-6
Ch 6 Hardware Reference
Model 100xx Connector
I/O Terminals
+5V, +12V, -12V
These screw terminals can be used to power
external devices. The maximum allowed current
specified in the table to the right should not be
exceeded, else the controller and/or the computer
could be damaged. To power an external device,
run a wire from a voltage output terminal (e.g.
"+5V) to the device and also run a wire from one
of the ground terminals (i.e. "GND") to the device
ground.
Specifications1
+5V
+12V
-12V
Network Utilization:
Network Interface
The Model 100 cables to a Controller and/or other
Network Devices via DB-25 cables.
Physical/Environmental
All I/O signals cable to the Model 100 via screw
terminals.
Power
Power consumed by the Model 100 Network
Device without additional Network Devices
attached, without a terminator, and without
outputs loaded. Total system power consumption
is the sum of the power consumed by the
Controller and each attached Network Device.
Compatibility:
Network Connector:
I/O Connector:
Dimensions:
Operating Temperature
Storage Temperature
Relative Humidity:
Power Consumption:
100 mA max.
30 mA max.
30 mA max.
Occupies 1 physical address
in instruNet Network
All instruNet Controllers and
Network Devices
DB-25 male connector
(input), DB-25 female
connector (out)
Screw Terminals
1.8" x 4.2" x 9"
0 to 70˚C
-25 to +85˚C
Up to 90% (non-condensing)
+5V @ 180mA max
+12V @ 80mA max
-12V @ 80mA max
Table 6.2 Model 100, 100B, and 100HC Technical Specifications.
1Measurement Accuracy
0-70°C, no condensation, #iNet-100xx Rev 3, temperature has not changed since self-calibration,
Accuracies are typical within 2 standard deviations. Accuracy is effected by the Channel Switching field
(i.e. set in the Setup dialog to Accurate or Fast) and the integration time. If the Channel Switching field is
set to Accurate, the signal is given more time to settle after the channel multiplexor is switched. Accurate
switching has a lower maximum sample rate than Fast switching.
Integration time is independently programmable for each channel, and reduces noise by averaging many
samples. Also, if more than 125 samples are averaged, a dithering noise generator automatically turns on
to add noise to the input signal. This increases the accuracy further by using more a/d codes to establish
the input volt
6-7
Ch 6 Hardware Reference
Model 300 Power Adaptor
Outbound Devices
+5V
-12V
+12V
EARTH SHIELD
COM
Toward Computer
Toward Computer
Outbound Devices
instruNet controllers
provide power to
external devices;
instruNet
however this power is
Power Adaptor
sometimes inadequate
#iNet-300
due to too many devices
DIGITAL HIGHWAY
on the network, or a
network length that
induces an unacceptable
Power In
voltage drop between
the controller and the
devices. Subsequently,
one can insert a Model 300 Power Adaptor inline the instruNet network,
preferably close to the Devices receiving power, and connect an external power
source (e.g. #iNet-311.x, 312.x, 322.x Power Supply) to the Model 300
External Power Source input connector. Multiple Model 300's can be placed in
one network (e.g. place one Model 300 every 4 Devices, in a 16 Device
network).
(earth) 2 (shield)
(+12V/.5A) 5
4 (-12V/.5A)
(+5V/1A) 3
1 (Com)
External Power Input
(Looking Into Male 5p DIN Plug)
Fig 6.3 Model 300 Power Adaptor Block Diagram
Controller
Computer
300
instruNet Device
#iNet-311
Power Supply
Fig 6.4 Example Application of Model 300 Power Adaptor
6-8
110V
Ch 6 Hardware Reference
Model 311.x, 312.x, 322.x Power Supplies
The following power supplies provide a 5pin Din output connector compatible with
the instruNet #iNet-300 Power Adaptor, #iNet-330 Electrical Isolator, and #iNet230 PC-Card. The 5pin DIN connector pin out is as follows: 1: Com, 2: n/c or
earth GND, 3: +5V, 4: -12V, 5: +12V.
Part #
Plug
VAC Input
Output
RECOMMENDATION
-----------------------------------------------------------------------------#iNet-312.8
USA 3-Prong
120/220 5V/2A, +-12V/.8A
#iNet-312.8eu Euro 2-Prong
120/220 5V/2A, +-12V/.8A
#iNet-311.2
#iNet-311.5
#iNet-322.5
Power Plugs
USA 3-Prong
USA 3-Prong
Euro 2-Prong
120
120
220
5V/.7A, +-12V/.24A
5V/2A, +-12V/.5A
5V/2A, +-12V/.5A
i311.x and i322.x
are discontinued buy i312.8 instead
USA 3 Prong Plug
USA 3 prong plugs mate with USA 110VAC wall sockets.
EURO 2 Prong Plug
Euro 2 prong CE plugs include a receptacle for an earth pin and they mate with
220VAC wall sockets in Germany, France, Italy, Spain (yet not UK).
Japan 110VAC Plug
Connecting to 110VAC Sockets in Japan requires replacing the iNet-3xx.y plug
with a Japanese plug.
If the power plug does not match your wall socket...
If the power plug doesn't fit, we recommend that it be removed and replaced
with one that does.
6-9
Ch 6 Hardware Reference
Model 330 Electrical Isolator
Toward Computer
Outbound Devices
The Model 330 Electrical
Isolator provides 1000 Volts
instruNet
of optical isolation at one
Electrical Isolator
point within an instruNet
#iNet-330
network. This is often used
DIGITAL
HIGHWAY
to eliminate ground loops
between the computer and
items under test, and to
Power In
reduce noise that is
transmitted from the
computer to sensors. When
measuring small voltages (e.g. <10mV), optical isolation is sometimes critically
important. The Model 330 Electrical Isolator is very similar to the Model 300
Power Adaptor, described earlier, except for its isolation capability. An external
power source (e.g. #iNet-312.8) must be connected to the 5pin DIN Power Source
Connector, to provide power to outbound devices. Multiple Model 330's can be
placed in one network (e.g. place one Model 330 every 4 Devices, in a 16 Device
network).
Outbound Devices
+5V
-12V
+12V
EARTH SHIELD
COM
Toward Computer
Optical Isolation
(earth) 2 (shield)
(+12V/.5A) 5
4 (-12V/.5A)
(+5V/1A) 3
1 (Com)
External Power Input
(Looking Into Male 5p DIN Plug)
Fig 6.5 Model 330 Electrical Isolator Block Diagram
Controller
Computer
330
instruNet Device
#iNet-311
Power Supply
Fig 6.6 Example Application of Model 330 Electrical Isolator
6-10
110V
Ch 6 Hardware Reference
Isolating From
Earth Ground
The External Power Input pins 1 and 2 are both tied to the outbound instruNet
device ground (case and pcb). If this is also tied to the 3rd prong of the power
supply AC input connector, and you want to isolate instruNet from this earth
ground, then you would need to place a 2-to-3 prong Adaptor at the power supply
input connector (or rip the 3rd prong out of the plug with a pair of strong pliers).
Wild Grounds
If the outbound devices are not seen by instruNet World, try temporarily holding a
wire between the outer shell of the isolator inbound and outbound DB-25
connectors. If the outbound devices are then seen by instruNet World (after Reset),
then this indicates that a very high frequency exists between the two grounds and is
causing problems. The Model 330 is designed to sustain a signal between the two
grounds that is 50V peak-to-peak with a 1000V/us slew rate (e.g. slews 1Volt in
1ns); and this is adequate is most applications.
Slower Speeds
Since the optical isolators introduce delays, the Model 330 reduces the speed of the
instruNet network from 4M bits/sec to 1.33M bits/sec, on short networks. In a
worse case scenario, this would reduce the maximum sample rate 3 to 1.
6-11
Ch 6 Hardware Reference
6-12
Ch 7 Channel Reference
Chapter 7,
Reference
Channel
The following table summarizes the Channels provided by each instruNet hardware
Device, the Settings offered by each channel, and the Fields within each Settings
group.
For documentation on channel settings unique to instruNet World PLUS (e.g. Panel
Meters, Control), please select "instruNet World+ Manual" in the "Help" menu
within instruNet World, or see Internet URL www.instrunet.com/plus.
Hardware
Device
Model 200 PCI,
Model 230
PC-Card
Controllers
Channel
Ch1...10
Digital Timer
I/O
Setting Group
General
Display
Timer
Ch 11 Time
General
Ch 12 Digitizer
Display
General
Timebase
Trigger
Continued...
Fields
Value I/O, Units Label, User Name
% Sample Rate
Digitize On/Off, Display Min,
Display Max, View Show/Hide
Function, Clk Period, Clk Out Hi,
Measure, Meas. Resol., Meas. Cycles
Time Secs, Units Label, User Name
% Sample Rate
On/Off, Max EU, Min EU
Value, Units Label, User Name,
% Sample Rate
Digitize Off/On, Pts Per Scan,
No. Of Scans, Min sec/tsfr, Sample Rate,
Scan Mode, Switching, Network BPS
Trigger Off/On, Threshold EU, Slope,
Trig. Net#, Trig. Dev#
Trig. Mod#, Trig. Chan#
Table 7.1 Channel Reference.
7-1
Ch 7 Channel Reference
Hardware
Device
Model 100
Analog &
Digital I/O
System
Channel
Ch1 Vin+,
Ch2 Vin-,
Ch4 Vin+,
Ch5 Vin-,
Ch7 Vin+,
Ch8 Vin-,
Ch10 Vin+,
Ch11 Vin-,
Ch13 Vin+,
Ch14 Vin-,
Ch16 Vin+,
Ch17 Vin-,
Ch19 Vin+,
Ch20 Vin-,
Ch22 Vin+,
Ch23 Vin-
Setting Group
General
Hardware
Constants
Display
Lowpass Filter
Highpass Filter
Bandpass Filter
Bandstop Filter
File
Driver Ram
User Ram
Ch3, Ch6, Ch9,
Ch12, Ch15,
Ch18, Ch21,
Ch24 Vout
Ch25 DIO
General
Display
General
Display
Hardware
Table 7.1 Channel Reference.
7-2
Fields
Value Input, Units Label, User Name
% Sample Rate
Sensor, Wiring, Low Pass, Integrate
Range
Ro, Rshunt, Vout, Vinit, alpha
delta/Rlead, GF, υ _Poisson
Digitize On/Off, Display Min,
Display Max, View Show/Hide
Filter type, PassB Ripple, StopB Attn
Filter Order, PassB F1 Hz, StopB F1 Hz
Filter type, PassB Ripple, StopB Attn
Filter Order, PassB F1 Hz, StopB F1 Hz
Filter type, PassB Ripple, StopB Attn
Filter Order, PassB F1 Hz, StopB F1 Hz,
PassB F2 Hz, StopB F2 Hz
Filter type, PassB Ripple, StopB Attn
Filter Order, PassB F1 Hz, StopB F1 Hz,
PassB F2 Hz, StopB F2 Hz
File, Digitize, File Name, Command
Scan Num, 1st Pt Num, Num Pts
Digitize On/Off, Buffer Addr,
Ptr Byte Size, Scan Num In,
Pt Num In, Scan Num Out, Pt Num Out
Digitize On/Off, User Ptr,
Ptr Bytes Size, Scan Num In,
Pt Num In, Scan Num Out, Pt Num Out
Value Output, Units Label, User Name,
% Sample Rate
Digitize On/Off, Display Min,
Display Max, View Show/Hide
Value Output, Units Label, User Name,
% Sample Rate
Digitize On/Off, Display Min,
Display Max, View Show/Hide
Digital Out, Direction
Ch 8 Settings Reference
Chapter 8, Settings
Reference
This chapter summarizes the Settings field groups used by the instruNet field
hierarchy. Each group may be used many times; for example, the Display group
contains 4 fields (Digitize On/Off, Display Min, Display Max, View Show/Hide)
and is used with 25 Channels in the Model 100 hardware device. Each Settings
group contains 1 to 8 fields, as described in the following table. And each field can
be set to a different value, as described in this table.
For Programmers:
Each Setting Group has an associated settingType value, which are passed to the
iNet() subroutine in the 'settingGroupNumOrType' argument. These are listed in
the 1st column of the table in subscript form. For example, the settingType of the
Filter Settings group is -11. These are also listed in the ion_settingGroupType area
of the interface .h file.
Each Field has an associated fieldNum value, which are be passed to the iNet()
subroutine in the 'fieldNum' argument. These is listed in the 2nd column of the
table in subscript form. For example, the fieldNum of the PassB Ripple field
within the Filter Settings group is 2. These are also listed in the fldnum_.... areas
of the interface .h file.
Some Fields have several possible values which are passed to the iNet() subroutine
in the 'ptrToArg' argument. These are listed in the 3rd column of the table in
subscript form. For example, the fieldValue for the Elliptic option of the Filter
field within the Filter Settings group is 2. These are also listed in the fldnum_....
areas of the interface .h file.
8-1
Ch 8 Settings Reference
Settings
Group
settingType
Field fieldNum
Field Description fieldValue
Defines a digital bandpass filter. For more information, please refer to
Chapter 2, Working with Digital Filters.
Bandpass
Filter -10
Filter1
PassB Ripple2
StopB Attn3
Filter Order4
PassB F1 Hz5
StopB F1 Hz6
Pass B F2 Hz7
Stop B F2 Hz8
Selects filter model = {Off1, Elliptic2, Chebyshev P3, Chebyshev S4, or
Butterworth5 }.
Specifies maximum allowable passband ripple, in dB.
Specifies the minimum stop band attenuation, in dB.
Displays filter order. Automatically determined by the filter design,
which is based on the specified criteria.
Specifies lower cutoff frequency of the band that is passed. Frequencies
between PassB F1 Hz5 and PassB F2 Hz7 are passed.
Frequencies below StopB F1 Hz6 are attenuated.
Specifies high cutoff frequency of the band that is passed. Frequencies
between PassB F1 Hz5 and PassB F27 Hz are passed.
Frequencies above StopB F2 Hz8 are attenuated.
Defines a digital bandstop filter. For more information, please refer to
Chapter 2, Working with Digital Filters.
Bandstop
Filter -11
Filter1
PassB Ripple2
StopB Attn3
Filter Order4
PassB F1 Hz5
StopB F1 Hz6
Pass B F2 Hz7
Stop B F2 Hz8
Selects filter model = {Off1, Elliptic2, Chebyshev P3, Chebyshev S4, or
Butterworth5 }.
Specifies maximum allowable passband ripple, in dB.
Specifies the minimum stop band attenuation, in dB.
Displays filter order. Automatically determined by the filter design,
which is based on the specified criteria.
Frequencies below PassB F1 Hz5 are passed.
Specifies lower cutoff frequency of the band that is stopped.
Frequencies between StopB F1 Hz6 and Stop B F2 Hz8 are stopped (i.e.
attenuated).
Frequencies above PassB F2 Hz7 are passed.
Specifies higher cutoff frequency of the band that is stopped.
Frequencies between StopB F1 Hz6 and Stop B F2 Hz8 are stopped (i.e.
attenuated).
Table 8.1 Channel Setting Group Reference
8-2
Ch 8 Settings Reference
Settings
Group
Field fieldNum
settingType
Field Description fieldValue
Defines constants used to calculate engineering units when measuring
sensors (e.g. RTD, strain gage, etc). For more information, please refer
to Chapter 3, Connecting To Sensors.
Constants -4
Ro1
Rshunt2
Vout3
Vinit4
alpha5
delta, Rlead6
GF7
υ_Poisson8
Directory -19
Path Name1
New Name2
Save Fields3
Load Fields4
Specifies value of bridge completion resistor, unstrained strain gage, load
cell w/ 0 force, potentiometer, or resistance of an RTD at 0°C. Units are
ohms.
Specifies value of shunt resistor in voltage divider or current
measurement circuit. Units are ohms.
Sets excitation voltage in bridge/voltage divider circuits. Units are Volts.
Specifies voltage across an unstrained bridge (e.g. strain gage, load cell);
the voltage of a pot in the CCW position; or the voltage out of an
accelerometer at 0 G's.
Specifies temperature coefficient of an RTD at 0°C (typically .00385 for
American RTD's, and .00392 for European RTD's), as specified by the
manufacturer of the RTD (ohms/ohms/C units); maximum force (Kg) in
the case of a load cell; or maximum acceleration (G's) in the case of an
accelerometer.
When connecting to an RTD, delta is the Callendar-Van Dusen delta
constant (typically 1.492). This constant is specified by the manufacturer
of the RTD. When doing measurements using quarter-bridge and halfbridge circuits, Rlead specifies the lead resistance of the wires connecting
the sensor (i.e. strain gage) to the bridge.
Specifies the gage factor of a Strain Gage as specified by the
manufacturer of the gage (i.e. relates resistance change to strain); V/V per
Kg of force in the case of a Load Cell; and V per G in the case of an
accelerometer.
Specifies Poisson's ratio in axial strain gage measurements.
Contains fields that specify where and how information is saved to, and
retrieved from, disk. For the most part, this is only used by programmers.
For more information, please refer to Chapter 4, Programming.
Specifies the path name for the directory/folder that is used when loading
or saving files via the Save or Open buttons in the Record page.
When the Save button is pressed in the Record page to save waveforms to
disk, a new directory/folder is created for the new files. If the New Name
field is set to Prompt User1, the user is prompted for the new folder's
name and location, otherwise, if New Name is set to Auto Generate2, the
folder is automatically created and named.
When the Save button is pressed in the Record page to save waves to
disk, the user has the option of saving the network Fields with the
waveforms. Save Fields is set to On1 if Fields are to be saved, and Off2
if they are not.
If Load Fields4 is set to On1, the network Fields are loaded from disk
when one presses the Open button in the Record page = {On1, or Off2}.
8-3
Ch 8 Settings Reference
File Type5
Specifies the file type for waveforms saved to disk via the Save button in
the Record page = { Binary1, Text (ASCII)2, Text Merge (ASCII)3,
Binary Merge4,}. Binary and Binary Merge are fast and compact,
whereas Text is compatible with other programs such as word processors
and spreadsheets. Text Merge saves an additional "Excel Waveform
Data.txt" text file that contains all waves in one file. Binary Merge saves
all channels in 1 file and spools to disk very fast; whereas Binary saves
each channel in its own file and uses less RAM memory.
Command6
Writing New Directory1 to the Command6 field causes a new
directory/folder to be created. Writing Show Dialog2 to the Command6
field causes the File Open dialog to appear, which enables one to modify
the Path Name field. Command6 is used primarily by programmers.
Table 8.1 Channel Setting Group Reference
Settings
Group
settingType
Field fieldNum
Defines the vertical scale of Record page Displays, and allows one to
enable a channel for digitizing.
Display -7
Digitize1
Display Max2
Display Min3
View4
Driver Ram -15
Digitize1
Buffer Addr2
8-4
Field Description fieldValue
If Digitize1 is set to On1, the channel is enabled for digitizing when the
Start button is pressed in the Record page = {On1, or Off2}. When turned
On within instruNet World, Input channels are Digitized and Plotted;
whereas Output channels are only plotted (one must use the iW+ Control
calculate field or Control script to drive output channels). When turned
On while programming (e.g. C/BASIC), input channels are enabled for
digitizing and their data is sent to data buffers; whereas output channels
are placed into the digitize list and fed with data from their data buffers at
the digitize sample rate.
Specifies the Engineering Units value that corresponds to the top line of a
Record page or Probe dialog snapshot display.
Specifies the Engineering Units value that corresponds to the bottom line
of a Record page or Probe dialog snapshot display.
Show1 or Hide2 Display in Record page while digitizing.
Defines a buffer, in RAM memory, that is maintained by the instruNet
Driver. This is used by programmers to hold digitized data. For more
information, please refer to Chapter 4, Programming.
If Digitize1 is set to On1, the channel is enabled for digitizing, and the
digitized data is sent to the Driver Ram buffer at runtime = {On1, or
Off2}.
This is the address, in RAM memory, of the Driver Ram Buffer; 0 if not
used (off). The Buffer size corresponds to 1 Scan of data points, where
each point is stored in a 32bit floating point number (4 bytes per point).
Ch 8 Settings Reference
Ptr Byte Size3
Scan Num In4
Pt Num In5
Scan Num6
Pt Num Out7
Specifies a file that contains digitized data. This is used primarily by
programmers. For more information, please refer to Chapter 4,
Programming.
File -17
File1
Digitize2
File Name3
Command4
Scan Num5
PointNum6
Num Pts7
General -6
This is the size of the Driver Ram Buffer in Bytes. This is often equal to
4 * PtsPerScan.
Scan Number of last data point pushed into Driver Ram Buffer = {1...
numScans}.
Point Number of last data point pushed into Driver Ram Buffer = {1...
PtsPerScan}
Scan Number of last data point pulled out of Driver Ram Buffer by
Access_Digitized_Data_In_Ram_Buffer() = {1...numScans}.
Point Number of last data point pulled out of Driver Ram Buffer by
Access_Digitized_Data_In_Ram_Buffer() = {1...PtsPerScan}.
If File1 is set to On1 the channel is linked to the file = {On1, or Off2}.
If Digitize2 is set to On1 the channel is enabled for digitizing, and the
digitized data is sent to the Driver Ram buffer at runtime = {On1, or
Off2}.
Specifies the file name that is linked to the channel. This is often the
same as the channel name (e.g. "Ch1 Vin+").
Writing to the Command4 field causes the following to occur (use the
Record window Open/Save commands to connect with datasets on disk):
File > Ram buf2 Transfer Num Pts7 (number of points) from the Scan
Num5 scan, starting at PointNum6, from the File to the
Driver Ram Buffer. If FileType is Binary Merge, this
occurs for all channels stored in the file for this
network.
File > User buf4 Same as File > Ram buf2, yet to User Ram Buffer.
Ram buf > File3 Transfer the data in the Driver Ram Buffer to the file on
disk. If FileType is Binary Merge, this occurs for all
channels stored in the file for this network.
User buf > File5 Same as Ram buf > File3, yet from User Ram Buffer.
Get File Info6 Get information about the File. Load {Scan Num5
PointNum6} with the last point in the file, and load
Num Pts7 with the number of points per scan .
Refers to a scan number = {1...numScans}.
Refers to the number of points in the last Scan = {1...PtsPerScan}.
Specifies general information about a channel, such as its name and
value.
8-5
Ch 8 Settings Reference
Value I/O1
Units Label2
User Name3
% Sample
Rate4
Hardware -3
with
Voltage
Input
Channels Sensor1
Specifies realtime value of the channel, in engineering Units. If the
channel is a voltage input, this reflects the realtime voltage at the input
terminals. If the channel is a voltage output, this is the voltage at the
output terminals.
Specifies vertical label that is shown in the Record page and Probe dialog
displays (e.g. "Volts", "C").
Specifies the name of the channel that is shown in the displays (e.g.
"Pressure1", "Temp2").
Specifies the channel's sample rate as a percentage of the master sample
rate that is defined in the Timing dialog (press Timing in Setup dialog) =
{.001...100}. For example, if the master sample rate is 1Ks/sec, and
Ch1's % Sample Rate4 is set to 25, then Ch1 will digitize at 250s/sec.
Specifies parameters that control a Voltage Input channel. For more
information, please refer to Chapter 2, Working with Sensors, and
Chapter 3, Connecting To Sensors.
Specifies type of sensor attached to Voltage input terminals = { Voltage1,
Current2, Resistance3, Strain Gage4, RTD5, Types J6, K7, T8, E9, R10, S11,
B12, N13 Thermocouple, Thermistor14, Load Cell16, Potentiometer17,
Accelerometer18 }.
Wiring2
Specifies wiring at Voltage input terminals = { Vin+ - Vin-1, Vin - Gnd2,
Shunt Resistor3, Voltage Divider4, Bridge5, Quarter Bridge6, Half Bridge
Bend7, Half Bridge Axial8, Full Bridge Bend9, Full Bridge Axial I10, Full
Bridge Axial II11 }.
Table 8.1 Channel Setting Group Reference
Settings
Group
Field fieldNum
Field Description fieldValue
settingType
Hardware Low Pass3
Continued
Integrate4
Range5
Hardware -5
with
Digital I/O
8-6
Specifies lowpass analog filter cutoff frequency in Hz (e.g. 0Hz = off,
40Hz, 4000Hz).
Specifies amount of integration (i.e. smoothing) in units of seconds.
Signal are sampled and averaged for the duration specified in this field.
For details, please see Application Notes #58 and #112.
Specifies maximum input range for the measured voltage, in units of
Volts. For the most accurate readings, specify the smallest range possible
without causing the measured voltage to hit the bound. For example if
your maximum expected input range is +-50 mV select a range of +-.3V
(i.e. set the Range5 field to .3).
Specifies parameters that control a Digital I/O channel (e.g. Ch25 Dio on
the Model 100 Device). For more information, please refer to Chapter 2,
Working with Digital I/O Channels.
Ch 8 Settings Reference
Digital Output1 Specifies the logic level of bits that have been set up as digital outputs in
the Direction2 field. Please see Chapter 2, Working with Digital I/O
Channels for details on how this is done.
Direction2
Sets the direction of the various digital bits as an input (0) or an output
(1).
Defines a digital highpass filter. For more information, please refer to
Chapter 2, Working with Digital Filters.
Highpass
Filter -9
Filter1
PassB Ripple2
StopB Attn3
Filter Order4
PassB F1 Hz5
StopB F1 Hz6
Pass B F2 Hz7
Stop B F2 Hz8
Selects filter model = {Off1, Elliptic2, Chebyshev P3, Chebyshev S4, or
Butterworth5 }
Specifies maximum allowable passband ripple, in dB.
Specifies the minimum stop band attenuation, in dB.
Displays filter order. Automatically determined by the filter design,
which is based on the specified criteria.
Frequencies above PassB F1 Hz5 are passed.
Frequencies below StopB F1 Hz6 are attenuated.
Not used.
Not used.
Defines a digital lowpass filter. For more information, please refer to
Chapter 2, Working with Digital Filters.
Lowpass
Filter -8
Filter1
Selects filter model = {Off1, Elliptic2, Chebyshev P3, Chebyshev S4, or
Butterworth5 }
PassB Ripple2 Specifies maximum allowable passband ripple, in dB.
StopB Attn3
Specifies the minimum stop band attenuation, in dB.
Filter Order4
Displays filter order. Automatically determined by the filter design,
which is based on the specified criteria.
PassB F1 Hz5 Frequencies below PassB F1 Hz5 are passed.
StopB F1 Hz6 Frequencies above StopB F1 Hz6 are attenuated.
Pass B F2 Hz7 Not used.
Stop B F2 Hz8 Not used.
Table 8.1 Channel Setting Group Reference
8-7
Ch 8 Settings Reference
Settings
Group
settingType
Field fieldNum
Field Description fieldValue
Specifies how waveforms are displayed and stored while digitizing. For
more information, please refer to Chapter 2, Digitizing Analog Signals
into the Computer and Chapter 5, Display Options.
Display
Options -18
Horiz Scale1
Specifies the horizontal scale of the displays in the Record page and
Probe dialog (i.e. Seconds per horizontal division). Use 0.0 to enable
automatic scale selection, which is based on the sample rate and Scan
size.
Horiz Pos2
Specifies the horizontal position of the displays in the Record page and
Probe dialog (i.e. seconds associated with the display left edge). This, in
effect, is linked to the horizontal scrollbar.
Plot3
Specifies whether to plot one dot per data point, or to connect data points
with lines = { Lines1, or Dots2 }. Lines1 requires more processor time.
Grid4
Turns display grid on or off = { On1, or Off2 }.
Max Pts/Pix5 Sets the maximum number of points plotted in each vertical column of
pixels.
Digitize Into6 Specifies where digitized data is saved = { Off1, ToRamBuffer2, ToFile3,
or UserControl4 }.
Overflow Alrt7 Specifies whether or not the instruNet driver shows an alert when the
Digitizer buffer overflows = { On1, or Off2 }.
Specifies the function of the Digital Timer I/O Channels on the Model
200 instruNet Controllers (not iNet-230). For more information, please
refer to Chapter 2, Working with Controller Digital Timer I/O Channels.
Timer -14
Function1
Sets the channel function as one of = { Digital In1, Digital Out2, Clock
Output3, Period Measurement4 }. See Chapter 2, Working with
Controller Digital Timer I/O Channels for details.
Clk Period2
Sets the cycle time, in seconds, when doing Clock Output.
Clk Out Hi3
Sets the high time, in seconds, when doing Clock Output.
Measure4
When doing Period Measurement, this specifies if the cycle time or the
high time is measured = { Cycle Time1, or High Time2 }.
Meas. Resol.5 When doing Period Measurement, this specifies the measurement
accuracy to one of = { .25µs1, or 4ms2 }.
Meas. Cycles6 When doing Period Measurement, this specifies the number of cycles or
high times that must elapse during the measured duration = {0...255}.
Table 8.1 Channel Setting Group Reference
8-8
Ch 8 Settings Reference
Settings
Group
settingType
Field fieldNum
Field Description fieldValue
Specifies parameters for the DSP based digitizing via the Model 200 and
230 instruNet Controllers. For more information, please refer to Ch2,
Digitizing Analog Signals into the Computer, & Ch 5, Timing Options.
Timing -12
Digitize1
Turns digitizing on or off for all channels = { On1, or Off2 }. This field
is automatically set to On1 when the Start button is pressed and Off2
when the Stop button is pressed.
Pts Per Scan2 Specifies the number of points digitized for each Scan, at the master
Sample Rate5.
No. of Scans3 Specifies the number of Scans that are digitized when the Start button is
pressed.
Scan Mode4
Specifies whether consecutive Scans are continuous with respect to each
other = { Strip Chart1, Oscilloscope2, Oscillo Queued3 }. Please refer to
Chapter 5, Strip Chart and Oscilloscope Scan Modes, for details.
Sample Rate5 Specifies the master sample rate, in units of samples-per-second-perchannel. If the specified rate is too fast, instruNet will adjust to the
fastest possible rate. All channels run at this rate, unless their % Sample
Rate4 field is requesting a slower rate.
Min sec/tsfr6
Specifies the minimum acceptable time to transfer a 16bit value on the
instruNet network, in units of seconds.
Network BPS7 Specifies the instruNet network data transfer rate in bits per second =
{100,000 ...4,000,000}. This is automatically set to the fastest possible
rate when instruNet is reset. Long network cables and/or many network
Devices sometimes require a slower rate.
Switching8
Specifies analog channel switching to run Fast2 or Accurate1. If Fast is
used, the system switches from one channel to another as fast as possible;
otherwise, with Accurate, the switching is a little slower, yet provides the
amplifiers more time to settle, and is therefore a little more accurate.
Table 8.1 Channel Setting Group Reference
8-9
Ch 8 Settings Reference
Settings
Group
settingType
Field fieldNum
Field Description fieldValue
Specifies the Trigger condition that must be met before digitizing (after
the Start button is pressed). For more information, please refer to
Chapter 2, Digitizing Analog Signals into The Computer, & Ch 5,
Trigger Options.
Trigger -13
Trigger1
Sets the trigger mode to one of: { Off1, Auto2, or Norm3 }. Off1 specifies
no trigger, Norm3 mandates that the digitizing cannot begin until the
trigger condition is met, and Auto2 waits for the trigger condition yet
digitizes anyway if the condition is not met within several seconds.
Threshold EU2 Specifies the trigger threshold in engineering units (EU).
Slope3
Specifies the direction the waveform must cross the threshold in order to
trigger = {Rising1, or Falling2}.
Expansion4
Trig. Net#5
Specifies the Network number of the trigger channel.
Trig. Dev#6
Specifies the Device number of the trigger channel.
Trig. Mod#7
Specifies the Module number of the trigger channel.
Trig. Chan#8 Specifies the Channel number of the trigger channel.
Defines a buffer, in RAM memory, that is maintained by the
programming end user. This buffer is used to hold digitized data. For
more information, please refer to Chapter 4, Programming.
User Ram -16
Digitize1
If Digitize1 is set to On1, the channel is enabled for digitizing, and the
digitized data is sent to the User Ram buffer at runtime = {On1, or Off2}.
User Addr2
This is the address, in RAM memory, of the User Ram Buffer; 0 if not
used (off). The Buffer size must be enough to hold 1 Scan of data points,
where each point is stored in a 32bit floating point number (4bytes/point).
Buff Byte Size3 This is the size of the User Ram Buffer in Bytes. This must be greater
than or equal to 4 * PtsPerScan.
Scan Num In4 Scan Number of last data point pushed into User Ram Buffer = {1...
numScans}.
Pt Num In5
Point Number of last data point pushed into User Ram Buffer = {1...
PtsPerScan}
Scan Num6
Scan Number of last data point pulled out of User Ram Buffer by
Access_Digitized_Data_In_Ram_Buffer() = {1...numScans}.
Pt Num Out7 Point Number of last data point pulled out of User Ram Buffer by
Access_Digitized_Data_In_Ram_Buffer() = {1...PtsPerScan}.
Table 8.1 Channel Setting Group Reference
8-10
Appendix I Troubleshooting
Appendix I, Troubleshooting
If your instruNet system is not operating properly, use the information in this
chapter to isolate the problem. If the problem appears serious enough to warrant
technical support, please contact your instruNet supplier.
Identifying Symptoms and Possible Causes
Use the Troubleshooting information in the following table to try to isolate the
problem. This table lists general symptoms and possible solutions for problems
with instruNet hardware and software.
Symptom
Computer crashes
when instruNet World
is run.
Possible Cause
The Controller board is not seated
properly, or it is damaged.
Digitized waveforms
appear to be invalid.
An open connection may exist on
a channel.
The sensor is not wired correctly.
The Field settings are not correct.
A Channel is configured as a
single-ended input while the
transducer is a differential type,
or vice-versus.
Possible Solution
Check the installation of the Controller
hardware and instruNet software per
directions in Chapter 1. Try rebooting
the computer. Also, refer to the next
section of this chapter entitled "... your
controller is not seen by the instruNet
World Software" paying careful
attention to the discussion about
making sure the card is properly seated
in its connector. Also, please refer to
Application Note #121.
Check the wiring to the input terminals.
Refer to Chapter 5 for instructions on
wiring sensors.
Refer to Chapter 5 Sensors Reference,
Chapter 7 Channel Reference &
Chapter 8 Settings Reference. It is
recommended that Chapter 2 instruNet
World Tutorial be completed before
attempting to wire sensors.
Check the wiring to instruNet and the
Wiring settings. Check the transducer
type.
Appendix I-1
Appendix I Troubleshooting
Computer will not boot
The Controller board is not seated
properly, or is damaged.
instruNet World opens,
yet does not see
Controller (i.e. only 3
rows of data are
displayed in Network).
The Controller board is not seated
properly, or is damaged.
Driver is not compatible with your
computer.
instruNet World opens
ok, yet does not see an
instruNet 100 Device
instruNet 100 device is not
connected to the instruNet
controller by an instruNet cable,
or instruNet cable is not well
seated.
instruNet Terminator not attached
to the end of the network.
In i100 and i200 units
manufactured before 9/1/97:
Blown power fuse (e.g. 5V, -12V
or +12V) in the Device, or in the
Controller (which could have been
caused by plugging in devices
while the power is on).
Bad instruNet Cable.
Broken Controller or Device.
Table AI-1 Troubleshooting
Appendix I-2
Check the installation of the Controller
hardware and instruNet software per the
directions in Chapter 1.
Please refer to the next section of this
chapter for information on this scenario.
Install latest version of driver, available
for free at www.instrunet.com. Beware
that if the driver files are also in the
same directory as the application (e.g.
in the same directory as "instruNet
World"), the application may use those
driver files instead of the one's in your
operating system directory; therefore,
make sure that both are current (or
delete the driver files in the same
directory as the application).
Use a flash light to make sure
connectors at the controller end and
device are well seated. Some
computers have a small corridor
through which the instruNet cable must
pass through to get to the instruNet
controller DB-25 connector, and in
some cases, this hole is not large
enough, and subsequently requires
reducing the size of the instruNet cable
molding with a knife.
Check Terminator.
To test if your fuses are ok, measure the
voltages at the 5V, -12V and +12V
screw terminals on the instruNet 100.
For example, to measure the +5V
voltage, place one voltmeter lead on the
"+5V" screw terminal and the other
lead on the "GND" screw terminal. If
the voltage is off by more than +/1V, a
fuse is probably blown in either the
instruNet 100 or the Controller card.
Please contact your instruNet supplier if
this is the case.
Try another cable.
Consult your instruNet supplier.
Appendix I Troubleshooting
If the instruNet PCI Controller Board is not seen by the
instruNet World software...
After installing the instruNet software per Chapter 1, one can easily verify its
installation by running the instruNet World software. If on Windows, select
"instruNet World" in the "instruNet" group within the START menu to run
instruNet World. When this software first opens, a list of instruNet resources are
listed in a spreadsheet like format. If only 3 rows of information are displayed,
then the software only sees the driver; if 15 rows are displayed then the Controller
(e.g. PCI) is seen as well; and if 40 rows are displayed, then an instruNet 100
network device is also seen. Also, to verify that these three items are installed, one
can click on the TEST tab at the bottom of the window, and press the SEARCH
button to display a list of installed resources (e.g. instruNet Driver, i200 Controller,
i100 Device).
If the Controller (e.g. pci or pcmcia card) is not seen on a Computer, then please
proceed with the following steps:
1. Use a flash light to make sure the board is well seated in its connector. With
some computers, it is difficult to insert the tab at the bottom of the I/O fence
into its receptacle. Sometimes, the I/O fence at the back of the computer is not
registered with respect to the motherboard, and tightening the I/O fence screw
causes the card to enter its connector at an angle. If this happens, leave the
screw loose and make sure the card is properly aligned in its connector so that
the pcb finders correctly align with their mating receptical pins.
2. Turn the computer power off for 10 seconds, turn it back on to boot the
computer, and then run "instruNet World" to see if the card is found. If it is not
found and you are running on a Windows computer, please power the computer
off, and then on again, since re configuring the cards internally sometimes
requires two power off/on cycles (sometimes due to plug-and-play arbitration
going on inside the computer).
3. If running under Windows, make sure "iNet32.DLL" Version ≥ 2.0 is installed
in the System directory, within the Windows directory (i.e.
"Windows\System\iNet32.dll" on a Win 95/98/Me computer, or
"Windows\System32\iNet32.dll" on a Win Nt/2k/Xp computer).
If on a PPC Macintosh, make sure "instruNet Driver (ppc)" Version ≥ 1.32.12
is installed in the System's Extensions folder.
If running under Windows Nt/2k/Xp, make sure you log on as the
Administrator before running the Setup.exe instruNet installer program, and
then restart your computer after running the Setup.exe.
Appendix I-3
Appendix I Troubleshooting
The latest software is available for download, free of charge, at
www.instrunet.com.
Beware that if the driver files are also in the same directory as the application
(e.g. in the same directory as "instruNet World"), the application may use those
driver files instead of the one's in your operating system directory; therefore,
make sure that both are current (or delete the driver files in the same directory
as the application).
4. If on a Windows computer: If you are running a video accelerator, try turning it
off, and see if this helps.
5. If your computer has several ISA or PCI cards that are not necessary for
computer operation (e.g. sound card, fax/modem card, scsi card, etc) then it is
recommended that you unplug them one at a time (while power is off), boot the
computer (for each case) and run the instruNet software.
6. It is possible the controller is broken. To detect this, try a different computer or
a different controller.
7. With older computers, it is sometimes possible that an old ISA card driver is
conflicting with a new PCI card. A conflict resolution program such as "First
Aid", or reinstalling the OS software, might remedy the problem.
8. If running under Windows with an instruNet PCI card, and instruNet Version
≤ 1.22 (1998) was previously installed on this computer, and you are now
running >1.22, then it might be necessary to remove some debris from the older
software. To do this, run The "System" Control Panel, select "Device
Manager", select "View Devices by connection", expand "PCI bus", if you see
"? PCI Card" select it & press the Remove button, and exit "System" Control
Panel. Then, reboot your computer, and when it asks for a PCI driver, Navigate
via the Browse button to "Program Files \ instruNet \ Internal \ PCI Win95
Driver \ inet95.inf". This inf file is installed on your computer when you run
the >1.22 instruNet Setupex.exe file. Then run "instruNet World" software
and look for >14 rows in the Network page, indicating that it found the pci
controller (if only 3 are shown, it means that it found the Driver software, yet
not a controller card).
9. Email a diagnostic report to your supplier, as noted in the following discussion.
10. Please refer to the Troubleshooting Application Notes at www.instruNet.com.
Appendix I-4
Appendix I Troubleshooting
Emailing a Diagnostic Report to your Supplier
To Email an instruNet Diagnostic Report to your Supplier: Run instruNet World
software, press the TEST tab, press the REPORT button to print the diagnostic
report to the window, copy the text to the clipboard (Windows Control C), paste the
text into an email window (Windows Control V) and then email to your instruNet
supplier for comment. A Diagnostic Report can also be generated by pressing the
"SAVE DEBUG REPORT TO DISK" button within an error alert. If there is a
conflict with other pci/pcmcia cards, then a emailing a registry report (another type
of report) via Application Note #184 might also be helpful.
Appendix I-5
Appendix I Troubleshooting
Appendix I-6
Appendix II instruNet Error Codes
Appendix II, Error Codes
The table below lists error codes returned by the instruNet driver along with
possible causes and solutions to the problem. These are instruNet error codes, and
are very different from your operating system error codes.
Error
Code
0
1
2
3
Error
Label
iNetErr_None
iNetErr_- General
iNetErr_-ControllerNotInitialized
iNetErr_InitFailed
4
iNetErr_-DeviceNumOutOfRange
5
iNetErr_-ChannelNumOutOfRange
6
iNetErr_FieldNum-OutOfRange
7
iNetErr_ControllerNot-Found
8
iNetErr_FieldDoesNotExist
9
iNetErr_-BadfieldNativeDataType
10
iNetErr_-BadFieldReadType
11
iNetErr_-TimeoutAtReadBegin
12
iNetErr_-TimeoutAtWaitFor-ReadDone
13
iNetErr_-ControllerIsInWeeds
iNetErr_illegalDataType
14
15
iNetErr_-FailedCopyDataTest
16
iNetErr_-CompressorHitError
iNetErr_FailedRam-Test
17
18
iNetErr_-RanOutOfMemory
Possible Cause
Possible Solution
no error
The operation was successfully completed.
potentially anything
instruNet has not been initialized
Try doing things differently and hope it goes away.
Check cables. Try pressing the Reset button. See Chapter 1.
instruNet initialization failed
Check network cables and termination. Check software installation.
Try pressing the Reset button.
Device number (deviceNum) is out Make sure all hardware Devices are connected and powered on.
of range
Press Search button in Test page for list of registered Devices.
Make sure the specified 'deviceNum' is correct. See Chapter 1.
Channel number is out of range
Make sure the specified 'chanNum' channel number parameter is
correct. See Chapter 7.
Field number is out of range
Make sure the specified 'fieldNum' field number parameter is
correct. See Chapter 8.
instruNet Controller not found
Make sure the specified 'netNum' network number parameter is
correct. Press Search button in Test page for list of registered
Networks. See Chapter 1, Hardware Installation.
specified {net, device, module, chan, Make sure the specified 'netNum', 'deviceNum', 'moduleNum',
setting, field} does not exist
'chanNum', 'settingNum', 'fieldNum' parameters are correct. See
Chapter 8.
bad data type
Make sure the specified 'netNum', 'deviceNum', 'moduleNum',
'chanNum', 'settingNum', 'fieldNum' parameters are correct.
bad read type
Make sure the specified 'netNum', 'deviceNum', 'moduleNum',
'chanNum', 'settingNum', 'fieldNum' parameters are correct.
time out at controller, crashed
Press Reset Button.
controller
time out at controller (crashed
Press Reset Button.
controller?)
crashed controller
Press Reset Button.
bad data type
failed the CopyWaveData() test or
bad instruNet Driver file
compressor hit error
failed board ram test
instruNet Driver ran out of memory
Make sure the specified 'netNum', 'deviceNum', 'moduleNum',
'chanNum', 'settingNum', 'fieldNum' parameters are correct. See
Chapter 8.
Try reinstalling installing Driver file and make sure you install
correct version of Driver.
Press Reset Button.
Power Computer off, then on. Press Big Test button in Test page.
Disconnect network cable from Controller. Controller might need
service.
Try giving calling application program more memory. Try reducing
the number of points per scan. Try a computer with more RAM.
Appendix II-1
Appendix II instruNet Error Codes
19
iNetErr_-AlertFailed
20
iNetErr_-CtrlrRomNotBooting
21
iNetErr_-CtrlrRamNotBooting
22
iNetErr_-DriverDownloadFailed
23
iNetErr_-CtrlrRWTestFailed
24
iNetErr_-InterfaceBlockTest-Failed
25
iNetErr_-IncCounterTestFailed
26
iNetErr_-EchoCmdToStatus-TestFailed
27
iNetErr_-ControllerBootTest-Failed
28
iNetErr_-ControllerFailedToBoot
29
iNetErr_-ControllerCmdFailed
30
iNetErr_GUI
31
iNetErr_-QSPI_Busy
32
iNetErr_-QSPI_Halted
33
iNetErr_-QSPI_ArgOutOfRange
34
iNetErr_-QSPI_TimeOutErr
35
iNetErr_-FlakyNetwork
36
iNetErr_-CouldNotLocateDriverFile
37
iNetErr_-netNumOutOfRange
38
iNetErr_-SettingGroupNumOut-OfRange
39
iNetErr_-UnitTypeOutOfRange
Appendix II-2
the routine that shows an alert failed Try reinstalling installing Driver file and make sure you install
correct version of Driver.
instruNet Controller's ROM does
Power Computer off, then on. Press Big Test button in Test page.
not seem to boot up (poss problem: Disconnect network cable from Controller to see if that fixes it.
controller, bus, rom)
Controller might need service.
instruNet Controller's driver in
Power Computer off, then on. Press Big Test button in Test page.
RAM does not seem to boot up
Disconnecting network cable from Controller might help.
(poss problem: controller, bus, ram, Controller might need service. Latest version of instruNet Driver
rom, download from uC, bad driver might help.
downloaded)
the download of the uController
Power Computer off, then on. Press Big Test button in Test page.
driver into uC ram failed (driver
Disconnecting network cable from Controller might help.
may be bad, or hardware is bad)
Controller might need service. Latest version of instruNet Driver
(the keys did not match).
might help.
failed during controller rw test in
Power Computer off, then on. Press Big Test button in Test page.
Test_DualPort_Ram()
Disconnecting network cable from Controller might help.
Controller might need service. Latest version of Driver might help.
Interface block between uController Power Computer off, then on. Press Big Test button in Test page.
and host computer is invalid
Disconnecting network cable from Controller might help.
Controller might need service. Latest vers. of instruNet Driver
might help.
Controller failed CounterInc test
Power Computer off, then on. Press Big Test button in Test page.
Disconnecting network cable from Controller might help.
Controller might need service. Latest vers. of instruNet Driver
might help.
Controller failed EchoCmdToStatus Power computer off, then on. Press Big Test button in Test page.
test
Disconnecting network cable from Controller might help.
Controller might need service. Latest vers. of instruNet Driver
might help.
Controller failed
Power Computer off, then on. Press Big Test button in Test page.
Test_A_Booted_Controller test
Disconnecting network cable from Controller might help.
Controller might need service. Latest vers. of instruNet Driver
might help.
Controller failed to Boot.
Power Computer off, then on. Press Big Test button in Test page.
Disconnecting network cable from Controller might help.
Controller might need service. Latest vers. of instruNet Driver
might help.
Controller failed to execute
Press Reset Button. Try doing things differently and hope it goes
command
away. Latest version of instruNet Driver might help.
error related to graphical user
Try reinstalling installing Driver file and make sure you install
interface
correct version of Driver.
QSPI is busy running
Press Reset Button. Try doing things differently and hope it goes
away. Latest version of instruNet Driver might help.
QSPI hit HALT error
Press Reset Button. Try doing things differently and hope it goes
away. Latest version of instruNet Driver might help.
QSPI argument out of range
Press Reset Button. Try doing things differently and hope it goes
away. Latest version of instruNet Driver might help.
QSPI hit time out error
Press Reset Button. Try doing things differently and hope it goes
away. Latest version of instruNet Driver might help.
QSPI is acting flaky
Check instruNet network cables. Make sure a network terminator is
properly installed. See Chapter 1, Hardware Installation.
could not find instruNet Driver file Make sure you installed the correct instruNet Driver file at the
in system folder
correct location on your computer. See Chapter 1, Software
Installation.
netNum is out of range
Make sure the specified 'netNum' network number parameter is
correct. Press the Search button in the Test page for a list of
registered Networks. See Chapter 1, Hardware Installation.
setting GroupNum is out of range
Make sure the specified 'settingGroupNum ' setting group number
parameter is correct. Press the Search button in the Test page for a
list of registered Networks and Devices. See Chapter 7.
deviceType is out of range
Check instruNet network cables. Make sure a network terminator is
properly installed. See Chapter 1, Hardware Installation.
Appendix II instruNet Error Codes
40
iNetErr_-DriverDidNotSetErr-Code
41
iNetErr_-SettingGroupTypeOutOf-Range
42
iNetErr_-ModuleNumOutOfRange
Module number is out of range
43
iNetErr_-IntentionNumOutOf-Range
Intention number is out of range
44
iNetErr_-ReadOnlyField
Cannot write to this field, read only
45
iNetErr_-WriteOnlyField
Cannot read from this field, write
only
46
iNetErr_-FieldValueOutOfRange
Tried to set a field with a value that
is too high or low
47
iNetErr_-ArgTypeOutOfRange
ArgType parameter is out of range
48
iNetErr_-BadKeyInField-Hierarchy
49
iNetErr_-Max_LT_MinInField-Hierarchy
50
iNetErr_-HierarchyFieldDataIn-Trouble
iNetErr_-ChannelNameInvalid
A BAD key was found in the field
hierarchy data -- internal data might
be corrupted
A maximum value is less than a
minimum value in the field
hierarchy -- internal data might be
corrupted
Hierarchical field data is in trouble - Latest version of instruNet Driver might help. Try pressing Reset
- internal data might be corrupted
button. Resetting computer might help.
51
52
iNetErr_-tempUnits_outOfRange
53
iNetErr_-sensorType_outOfRange
iNetErr_-CircBufErr
54
55
iNetErr_-DataBufferOverflow
56
iNetErr_-PulledTooMuchOn-LastPull
57
ERequired_fbx_DCIIR
58
EFreqToo-Large_fx_DCIIR
59
EFreqsNotAscending_-DCIIR
60
ERequired_-fx_DCIIR
61
ERequired_adelx_DCIIR
62
63
EInvalidArg_-DCIIR
64
EEven_-ndeg_DCIIR
65
EOrderTooLow_DCIIR
EOrderTooHigh_DCIIR
Driver did not get a chance to set
the error code; therefore Driver, or
interface to Driver, is in trouble
settingGroupType is out of range
Check the interface to Driver. Make sure you installed the correct
instruNet Driver file at the correct location on your computer. See
Chapter 1, Software Installation.
Make sure the specified 'settingGroupType' setting group type
parameter is correct. Press the Search button in the Test page for a
list of registered Networks and Devices. See Chapter 8.
Make sure the specified 'moduleNum' module number parameter is
correct (it is usually 1). Press the Search button in the Test page for
a list of registered Networks and Devices.
Make sure the specified 'intention' intention number parameter is
correct. See list of valid 'ion_intention' values in interface .h file.
Make sure the specified 'netNum', 'deviceNum', 'moduleNum',
'chanNum', 'settingNum', 'fieldNum' parameters are correct. See
Chapter 8.
Make sure the specified 'netNum', 'deviceNum', 'moduleNum',
'chanNum', 'settingNum', 'fieldNum' parameters are correct. See
Chapter 8.
Make sure the specified 'netNum', 'deviceNum', 'moduleNum',
'chanNum', 'settingNum', 'fieldNum' parameters are correct. See
Chapter 8.
Make sure specified 'argType' parameter is correct. See list of valid
'instruNetDataType' values in interface .h file.
Check network cables. Make sure a network terminator is properly
installed. Latest version of instruNet Driver might help. Try
pressing Reset button. Resetting computer might help.
Latest version of instruNet Driver might help. Try pressing Reset
button. Resetting computer might help.
The channel name is in trouble -internal data might be corrupted
temperature scale {C,K,F} out of
range
sensor type out of range
Latest version of instruNet Driver might help. Try pressing Reset
button. Resetting computer might help.
Check temperature measurement hardware and software.
circular digitizing data buffer error
Try a slower sample rate, or ask instruNet to do less while
digitizing.
Try a slower sample rate, or ask instruNet to do less while
digitizing.
Try a slower sample rate, or ask instruNet to do less while
digitizing.
Check digital filter Frequency Cutoff fields.
circular digitizing data buffer
overwrote data before it was read
circular digitizing data buffer error
where pulled too much on last pull
At least one cutoff frequency
(passband or stopband) is needed
for each transition band of bandpass
and bandstop digital filters
Cutoff frequency must be less than
half the sampling rate
Cutoff frequency negative or
frequencies not in ascending order
Missing one or more cutoff
frequencies
Missing passband ripple and or
stopband attenuation
Invalid argument
Necessary or specified filter order is
too high -- maximum order is %d
Filter order must be even for
bandpass and bandstop filters -order being increased by 1
Specified filter order is too low -order being automatically increased
Check sensor hardware and software.
Check digital filter Frequency Cutoff fields and make sure they are
lower than half the sample rate.
Check digital filter Frequency Cutoff fields.
Check digital filter Frequency Cutoff fields.
Check digital filter Ripple and Attenuation fields.
Check digital filter fields.
Reduce the digital filter Attenuation field value, or increase the
Ripple field value.
Reduce the digital filter Attenuation field value, or increase the
Ripple field value.
Increase the digital filter Attenuation field value, or decrease the
Ripple field value.
Appendix II-3
Appendix II instruNet Error Codes
66
EActualOrder-_DCIIR
67
iNetErr_-InterfaceCompiledBadly
68
iNetErr_-BadInterfaceKey
69
iNetErr_-BadAddrPassedToDriver
70
iNetErr_-BadStaticVarInDriver
71
iNetErr_-BadIntegerMathInDriver
72
iNetErr_-BadChannelType
73
iNetErr_-CppCompilerDidBad
74
iNetErr_-MemMngr_Failed
75
iNetErr_-Toolbox_Failed
76
iNetErr_-CrtRect_Failed
77
iNetErr_-DlogCode_Failed
78
iNetErr_-DrvrNeedsFpu_Failed
79
iNetErr_-iirCode_Failed
80
iNetErr_-sprintf_Failed
81
iNetErr_-DigitizeInit
82
iNetErr_-SPEoff
83
iNetErr_-Halton
84
iNetErr_-QPTQP
85
iNetErr_-qBusy
86
iNetErr_-abort
87
iNetErr_-cBusy
88
iNetErr_-cNotFin
89
90
iNetErr_-CodeGen
iNetErr_-CPTQPbad
Appendix II-4
Required filter order = %d (%s
biquadratic section%s)
a variable type in interface file (e.g.
INET_INT.C) is bad
Check digital filter fields.
Latest version of instruNet Driver might help. Try pressing Reset
button or Resetting computer Check Interface to, and installation
of, instruNet Driver.
the 'key' field passed to driver is bad Latest version of instruNet Driver might help. Try pressing Reset
button or Resetting computer Check Interface to, and installation
of, instruNet Driver.
bad address passed to driver
Latest version of instruNet Driver might help. Try pressing Reset
button or Resetting computer Check Interface to, and installation
of, instruNet Driver.
bad static variable in driver
Latest version of instruNet Driver might help. Try pressing Reset
button or Resetting computer Check Interface to, and installation
of, instruNet Driver.
bad integer math in driver
Latest version of instruNet Driver might help. Try pressing Reset
button or Resetting computer Check Interface to, and installation
of, instruNet Driver.
bad channel Type
Latest version of instruNet Driver might help. Try pressing Reset
button or Resetting computer Check Interface to, and installation
of, instruNet Driver.
Cpp compiler failed
Latest version of instruNet Driver might help. Try pressing Reset
button or Resetting computer Check Interface to, and installation
of, instruNet Driver.
Memory Manager failed
Latest version of instruNet Driver might help. Try pressing Reset
button or Resetting computer Check Interface to, and installation
of, instruNet Driver.
Toolbox failed
Latest version of instruNet Driver might help. Try pressing Reset
button or Resetting computer Check Interface to, and installation
of, instruNet Driver.
CrtRect failed
Latest version of instruNet Driver might help. Try pressing Reset
button or Resetting computer Check Interface to, and installation
of, instruNet Driver.
Dialog Code failed
Latest version of instruNet Driver might help. Try pressing Reset
button or Resetting computer Check Interface to, and installation
of, instruNet Driver.
Driver file needs FPU
Latest version of instruNet Driver might help. Try pressing Reset
button or Resetting computer. Check Interface to, and installation
of, instruNet Driver.
iir code failed
Latest version of instruNet Driver might help. Try pressing Reset
button or Resetting computer. Check Interface to, and installation
of, instruNet Driver.
sprintf failed
Latest version of instruNet Driver might help. Try pressing Reset
button or Resetting computer. Check Interface to, and installation
of, instruNet Driver.
Digitize initialization failed
Press Reset Button. Try doing things differently and hope it goes
away. Latest version of instruNet Driver might help.
instruNet network error
Press Reset Button. Try doing things differently and hope it goes
away. Latest version of instruNet Driver might help.
instruNet network error
Press Reset Button. Try doing things differently and hope it goes
away. Latest version of instruNet Driver might help.
instruNet network error
Press Reset Button. Try doing things differently and hope it goes
away. Latest version of instruNet Driver might help.
instruNet network is busy before
Press Reset Button. Try doing things differently and hope it goes
digitize
away. Latest version of instruNet Driver might help.
we aborted early
Press Reset Button. Try doing things differently and hope it goes
away. Latest version of instruNet Driver might help.
controller is busy doing something
Press Reset Button. Try doing things differently and hope it goes
away. Latest version of instruNet Driver might help.
controller did not finish the
Press Reset Button. Try doing things differently and hope it goes
command
away. Latest version of instruNet Driver might help.
code generation segment error
Latest version of instruNet Driver might help.
instruNet network error
Press Reset Button. Try doing things differently and hope it goes
away. Latest version of instruNet Driver might help.
Appendix II instruNet Error Codes
91
92
Latest version of instruNet Driver might help.
Try reducing the sample rate, making displays much smaller,
plotting less PointsPerPixel.
iNetErr_-nonCompOS
93
non-compatible operating system
Latest version of instruNet Driver might help.
iNetErr_bad94
bad channel Points-Per-Scan value
Try a different Points-Per-Scan (i.e. press Timing button) or '%
ChPtsPerScan
sample rate'.
iNetErr_-DestBuff 95
destination buffer not found
Latest version of instruNet Driver might help. Try pressing Reset
NotFound
button or Resetting computer Check Interface to, and installation
of, instruNet Driver.
Please search for "iNetErrorCode" in file "… program files \ instrunet \ Programming Interfaces \ Visual C .Net \ Source_Bak \
96 to
200
iNet_int.h" for details.
10000 to Controller Status
this is an error code from the
Press Reset Button. Try doing things differently and hope it goes
10255 Register Error
instruNet controller Status register
away. Latest version of instruNet Driver might help.
OS Error
-1 to
this is an error code from the
Press Reset Button. Try doing things differently and hope it goes
-32000
Operating System
away. Latest version of instruNet Driver might help.
iNetErr_-Compiler
iNetErr_-bOverflow
compiler error
driver or user ram buffer overflow
Table AII - Error Codes
Appendix II-5
Appendix II instruNet Error Codes
Appendix II-6
Appendix III Working With Spreadsheets
Appendix III, Working With
Spreadsheets
instruNet supports the acquisition of data into instruNet World with Export to a spreadsheet, postacquisition; and also supports the digitizing of data directly into an Excel spreadsheet, in realtime, via the
"Direct To Excel" program described in Chapter 2.
Appendix III-1
Appendix III Working With Spreadsheets
Exporting a file to a spreadsheet, postacquisition, is done by first acquiring data into
instruNet World software, saving it to disk in
the form of a text file, and then opening that
text file with a spreadsheet, as illustrated to
the left. To do this, one would:
1. Run instruNet World.
2. Select channels for digitizing in the
Network Page.
3. Press the Record tab.
4. Press the Setup button to open the Setup
dialog. Select Digitize Into: To Ram
Buffer, select File Type: Text Merge,
select the desired Sample Rate, select the
desired Pts Per Scan, set the No of Scans
to 1, set Scan Mode to Oscillo, and press
OK to exit the dialog.
5. Press the Network tab, press the Save
button to save these settings to disk, and
then press the Record tab to return to the
Record page.
6. Press the Start button to begin recording,
and the Stop button to stop recording.
7. Press the Save button in the Record page
(or, if running instrunet World+, one can
select Save Waveforms To Excel in the
Record menu) to save the data to disk in a
text file named "Excel Waveform
Data.txt". This file places each channel in
its own column, and looks something like
the illustration to the left when opened
with a spreadsheet program.
Columns are separated with TAB characters,
and rows are separated with CARRIAGE
RETURN characters.
Appendix III-2
Appendix IV Working with instruNet Files
Appendix IV, Working With
Application Software
DASYLab
instruNet is compatible with DASYLab software Version ≥ 4.01.11 and Version
>1.27 of the instruNet Driver. DASYLab with instruNet runs on a Windows ≥
95 computer and is fully 32bit compatible.
DASYLab is the easy-to-use data acquisition software application. Its
outstanding analysis and display features make it the ideal tool for many types of
measurement and control applications. Designed as an open system, DASYLab
contains drivers for more than 250 different data acquisition devices as well as
software interfaces and extension toolkits. With its unique structure, DASYLab is
able to acquire data up to 1 MHz into the PC's RAM, stream data to disk at up to
400 kHz and display data online at up to 150 kHz. For details, please select
"Programs / instruNet / Application Software / DasyLab /" in the Windows START
menu.
Appendix IV-1
Appendix IV Working with instruNet Files
LabVIEW
instruNet Drivers for the Macintosh & Windows Version of LabVIEW ≥ 4 are
available. The part numbers for these low cost drivers are listed below. Please
consult their documentation for information on how to link instruNet to LabVIEW.
In summary, they provide LabVIEW icons for many of the instruNet functions
described in Ch4 Programming, and provide examples of their use. For details,
please select "Programs / instruNet / Application Software / LabVIEW /" in the
Windows START menu.
#iNet-380
instruNet Drivers for Mac & Windows LabVIEW
#iNet-380-10x Ten more iNet-380's after buying 1st one
#iNet-381
instruNet LabVIEW Driver 1year Update
HP VEE
InstruNet is compatible with HP Vee Version ≥4.0 on Windows. For details,
please select "Programs / instruNet / Application Software / HP Vee /" in the
Windows START menu.
TestPoint
InstruNet is compatible with TestPoint Version ≥3.0 on Windows. For details,
please select "Programs / instruNet / Application Software / TestPoint /" in the
Windows START menu.
Appendix IV-2
WARRANTY/DISCLAIMER
OMEGA ENGINEERING, INC. warrants this unit to be free of defects in materials and workmanship for a
period of 13 months from date of purchase. OMEGA’s WARRANTY adds an additional one (1) month
grace period to the normal one (1) year product warranty to cover handling and shipping time. This
ensures that OMEGA’s customers receive maximum coverage on each product.
If the unit malfunctions, it must be returned to the factory for evaluation. OMEGA’s Customer Service
Department will issue an Authorized Return (AR) number immediately upon phone or written request.
Upon examination by OMEGA, if the unit is found to be defective, it will be repaired or replaced at no
charge. OMEGA’s WARRANTY does not apply to defects resulting from any action of the purchaser,
including but not limited to mishandling, improper interfacing, operation outside of design limits,
improper repair, or unauthorized modification. This WARRANTY is VOID if the unit shows evidence of
having been tampered with or shows evidence of having been damaged as a result of excessive corrosion;
or current, heat, moisture or vibration; improper specification; misapplication; misuse or other operating
conditions outside of OMEGA’s control. Components in which wear is not warranted, include but are not
limited to contact points, fuses, and triacs.
OMEGA is pleased to offer suggestions on the use of its various products. However,
OMEGA neither assumes responsibility for any omissions or errors nor assumes liability for any
damages that result from the use of its products in accordance with information provided by
OMEGA, either verbal or written. OMEGA warrants only that the parts manufactured by the
company will be as specified and free of defects. OMEGA MAKES NO OTHER WARRANTIES OR
REPRESENTATIONS OF ANY KIND WHATSOEVER, EXPRESSED OR IMPLIED, EXCEPT THAT OF
TITLE, AND ALL IMPLIED WARRANTIES INCLUDING ANY WARRANTY OF MERCHANTABILITY
AND FITNESS FOR A PARTICULAR PURPOSE ARE HEREBY DISCLAIMED. LIMITATION OF
LIABILITY: The remedies of purchaser set forth herein are exclusive, and the total liability of
OMEGA with respect to this order, whether based on contract, warranty, negligence,
indemnification, strict liability or otherwise, shall not exceed the purchase price of the
component upon which liability is based. In no event shall OMEGA be liable for
consequential, incidental or special damages.
CONDITIONS: Equipment sold by OMEGA is not intended to be used, nor shall it be used: (1) as a “Basic
Component” under 10 CFR 21 (NRC), used in or with any nuclear installation or activity; or (2) in medical
applications or used on humans. Should any Product(s) be used in or with any nuclear installation or
activity, medical application, used on humans, or misused in any way, OMEGA assumes no responsibility
as set forth in our basic WARRANTY/DISCLAIMER language, and, additionally, purchaser will indemnify
OMEGA and hold OMEGA harmless from any liability or damage whatsoever arising out of the use of the
Product(s) in such a manner.
RETURN REQUESTS/INQUIRIES
Direct all warranty and repair requests/inquiries to the OMEGA Customer Service Department. BEFORE
RETURNING ANY PRODUCT(S) TO OMEGA, PURCHASER MUST OBTAIN AN AUTHORIZED RETURN
(AR) NUMBER FROM OMEGA’S CUSTOMER SERVICE DEPARTMENT (IN ORDER TO AVOID
PROCESSING DELAYS). The assigned AR number should then be marked on the outside of the return
package and on any correspondence.
The purchaser is responsible for shipping charges, freight, insurance and proper packaging to prevent
breakage in transit.
FOR WARRANTY RETURNS, please have the
following information available BEFORE
contacting OMEGA:
1. Purchase Order number under which the product
was PURCHASED,
2. Model and serial number of the product under
warranty, and
3. Repair instructions and/or specific problems
relative to the product.
FOR NON-WARRANTY REPAIRS, consult OMEGA
for current repair charges. Have the following
information available BEFORE contacting OMEGA:
1. Purchase Order number to cover the COST
of the repair,
2. Model and serial number of the product, and
3. Repair instructions and/or specific problems
relative to the product.
OMEGA’s policy is to make running changes, not model changes, whenever an improvement is possible. This affords
our customers the latest in technology and engineering.
OMEGA is a registered trademark of OMEGA ENGINEERING, INC.
© Copyright 2008 OMEGA ENGINEERING, INC. All rights reserved. This document may not be copied, photocopied,
reproduced, translated, or reduced to any electronic medium or machine-readable form, in whole or in part, without the
prior written consent of OMEGA ENGINEERING, INC.
Where Do I Find Everything I Need for
Process Measurement and Control?
OMEGA…Of Course!
Shop online at omega.com SM
TEMPERATURE
䡺
⻬
䡺
⻬
䡺
⻬
䡺
⻬
䡺
⻬
Thermocouple, RTD & Thermistor Probes, Connectors, Panels & Assemblies
Wire: Thermocouple, RTD & Thermistor
Calibrators & Ice Point References
Recorders, Controllers & Process Monitors
Infrared Pyrometers
PRESSURE, STRAIN AND FORCE
䡺
⻬
䡺
⻬
䡺
⻬
䡺
⻬
Transducers & Strain Gages
Load Cells & Pressure Gages
Displacement Transducers
Instrumentation & Accessories
FLOW/LEVEL
䡺
⻬
䡺
⻬
䡺
⻬
䡺
⻬
Rotameters, Gas Mass Flowmeters & Flow Computers
Air Velocity Indicators
Turbine/Paddlewheel Systems
Totalizers & Batch Controllers
pH/CONDUCTIVITY
䡺
⻬
䡺
⻬
䡺
⻬
䡺
⻬
pH Electrodes, Testers & Accessories
Benchtop/Laboratory Meters
Controllers, Calibrators, Simulators & Pumps
Industrial pH & Conductivity Equipment
DATA ACQUISITION
䡺
⻬
䡺
⻬
䡺
⻬
䡺
⻬
䡺
⻬
Data Acquisition & Engineering Software
Communications-Based Acquisition Systems
Plug-in Cards for Apple, IBM & Compatibles
Datalogging Systems
Recorders, Printers & Plotters
HEATERS
䡺
⻬
䡺
⻬
䡺
⻬
䡺
⻬
䡺
⻬
Heating Cable
Cartridge & Strip Heaters
Immersion & Band Heaters
Flexible Heaters
Laboratory Heaters
ENVIRONMENTAL
MONITORING AND CONTROL
䡺
⻬
䡺
⻬
䡺
⻬
䡺
⻬
䡺
⻬
䡺
⻬
Metering & Control Instrumentation
Refractometers
Pumps & Tubing
Air, Soil & Water Monitors
Industrial Water & Wastewater Treatment
pH, Conductivity & Dissolved Oxygen Instruments
M2773/1008
Was this manual useful for you? yes no
Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Download PDF

advertisement