Easily measure electrical currents (e.g. 4 to 20mA) with Windows ≥ XP Sp3.
instruNet also connects directly to
.
The i60x
is a tiny standalone USB device with 8 channels;
whereas the larger i555
involves an 8 to 256 channel
card cage with optional
anti-aliasing filter.
The i601 is the
smallest and most accurate data acquisition system with
electrical isolation that connects directly to sensors.
Includes Free
instruNet World
strip chart recorder software; or purchase powerful
PLUS version.
Compatible with LabVIEW, DASYLab, MATLAB, Origin, C and Visual BASIC Software.
Digitize any combination of channels at 166,000 samples per second aggregate.
To connect a
Current Source
to instruNet, please do the following steps:
Install instruNet hardware and software version ≥ 3.7 as described
here.
Unplug USB cable to i60x device while wiring
sensors and while plugging into i60x Hd44 Connector
i4xx/i555:
Remove 110/220 VAC power to i312.8 power supply while wiring sensors
and
while connecting i51x wiring box to Hd44 Connector
Press the blue Quick Setup button for the channel you want to set up (requires ≥ v3.7).
Select Current in the Stimulus menu.
Below is an example setup.
Enter the expected minimum and maximum expected current (e.g. 0.004 to 0.020 Amps).
Physically attach your sensor per the wiring diagram in the dialog (which will match your sensor).
An example is shown below.
Attach a precision shunt resistor (e.g.
33 ohms, 0.05%, ≤5ppm/°C) as shown in the diagram, and
update the Shunt Resistor field with it's value. See Suggestions box for suggested shunt resistor value.
The Integrate field determines how long the signal is averaged before instruNet returns one number (i.e. one "point" in digitized waveform). Careful, this averaging fully consumes the instruNet controller, and therefore reduces the maximum possible sample rate,
as noted here.
A 0.0001 or 0.001 second integration time is often very helpful at reducing noise and increasing accuracy.
If you digitize slowly (e.g. slower than 10 samples-per-second-per-channel), set Integration to "0.016666" seconds (or 0.02 seconds if power is 50Hz).
This will average each point over one 110/220Vac
power line cycle and drastically reduce noise.
To see the maximum sample rate given your setup, click here.
If working with an i423 card, adjust the analog Low Pass filter as needed (e.g. 6Hz or 4KHz).
If working with an i500
anti-aliasing filter, click here.
View measured value in lower left corner of Quick Setup dialog or Network page.
Apply stimulus to sensor. Does value look correct? If not consider the following steps:
Click
Sensor Reportand/orUser's Manual buttons
at bottom of dialog.
Debug wiring with handheld voltmeter.
Measure voltage between each wiring diagram node and instruNet GND. Are they what you would expect given the circuit?
To include a channel in the instruNet World RECORD page: set the Enable Digitize field to ON (which occurs automatically when you first enter the Quick Setup dialog) or click the channel's red rectangle in the NETWORK page. This rectangle is to the right of the blue Quick Setup button, as shown above.
Several buttons at the bottom of the dialog help with setup.
Click Multiple Channels to copy your
setup to any number of subsequent channels,
click Record Page to jump to the Record page,
click Channel Setup to open the
Channel Setup
dialog, and click Reset Parameters to reset
all visible parameters.
The lower right corner of the Quick Setup dialog provides access to the master Timebase settings. These numbers are common (the same) to all channels that appear in the RECORD page. Samples-Per-Second-Per-Channel is the number of points that are digitized each second for each channel. A scan is a buffer in RAM memory, and Points-Per-Scan are the number of points in that buffer for each channel. Number-Of-Scans is the number of times you fill that RAM buffer. Try setting Points-Per-Scan to 100, Number-Of-Scans to 1 and Samples-Per-Second-Per-Channel to 10. Press the Digitize button in the lower left corner to close the Quick Setup dialog, select the RECORD page and start digitizing. In the Record page, one can press START to start digitizing and STOP to stop. To jump between RECORD and NETWORK pages, click tab at bottom of window. For more details on digitizing,
click here.
Save your settings in a .prf file by pressing the SAVE
button in the NETWORK page (not Record page).
To get these back, click OPEN in the Network page.
To further learn how to use instruNet, click
Software Tutorial.
To learn about instruNet products, click
here.