NI 9222 Amplification

[Dennis_Knutson]

Your first post said it was reading 5 V. You have to be getting either some reading (incorrect or not), or an error. The 5 V trading would indicate to me either an open circuit or a defective unit. Did you do the basic troubleshooting step I suggested?

[dariley]

Correct, I get a 5V signal when I attach it to our sensor undergoing tests. A multimeter and oscillscope recorded ~150mV during the same test. When the module has no input source wired in, LabVIEW essentially shows a 0V signal. I tried your battery test and LabVIEW recorded a signal nearly idential to that of a module without an input.  I measured the voltage of the battery with a multimeter, and it read 1.5V. I have done a similar test in the past using a sine wave generator. In this scenario, I again recorded an amplified signal in LabVIEW compared to what my multimeter read. I do not recall the specific values, however.

[Dennis_Knutson]

Can it be assumed that you did the same sort of tests on the other inputs? If you did and got similar results, then I think it's likely the whole device is damaged and you need to arrange an rma.

[dariley]

Yes, the tests have been performed on multiple channels. The only issue with arranging an RMA is the fact that I am in the middle of an animal testing period, and I have been using and plan to continue to use the malfunctioning device. I am particularly interested a transfer function-like ratio of two sensors (output divided by the input). Therefore, as long as the malfunction affects the sensors identically (which is seems to be doing), our data is not greatly affected. Once the animal testing portion of my experiment concludes, I will look into submitting an RMA.

Thank you for your advice!