DAQ Assistant NI-9205 configure input voltage range

[therbert]

How do you configure the NI9205 module to use the +/-200mV range input.

I am using a custom scale and it appears I can't get an accurate reading.  I am using a 100mA current shunt (10A max).  So I have the custom scale setup to have 100x + b.  The current flowing through the device is 2 amps and I am getting a reading of 12-13 amps after custom scaling.  At this time I am thinking the module is setup to sample for 10V input and I am getting a resolution error.

[chris88 · Accepted solution]

Hi therbert

Since your custom scale is 100x, to work on the range of +/- 200mV of your NI 9205 you should configure your input signal range max and min to +/- 20 respectively.

Following the equation: Range.max * scale.slope =  200mV * 100 =  20V

This will configure the range of the module automatically to +/- 200 mV, to check it you can access the DAQmx Channel Property Node and search for the Analog Input >>General Properties>>Advanced>>Range property, this will let you know in which range is the device working.

Regards