myRio analog signal in LabVIEW

[pier2593]

Hi all,

I am currently working on acquiring a 40kHz frequency through A/AI0 channel of the myRio board.  With LabVIEW, I am able to acquire half of the waveform.  Only the positive side of the waveform is shown for some reason.  I was wondering if there is a setting in LabVIEW to change this problem or in myRio.  I should be getting a -1V to +1V peak-to-peak waveform.  Instead, I am getting only the waveform from 0 to +1V and it is clipped at 0.  

Thank you for your help! 

[Nathan-P]

Hi pier2593,

That is expected behavior, because the AI inputs on the MXP A Connector is uni-polar.  This is documented in the specifications for your device (Table 1 on page 5 of the link below)

http://www.ni.com/pdf/manuals/376047a.pdf

Here is a screenshot for convenience:

In summary: The channel you selected can only measure 0-5V.

If you need to measure a -1V to 1V signal, you will need to use the AI0/AI1 on the MSP (Connector C) on the myRIO.  These two AI inputs support +-10V.

I hope this helps and good luck!

Regards,

Nathan P.

[pier2593]

How would you go about using the +/- differential analog input channels?  For the moment, I am simply sending a 40kHz signal to the analog input C/AI0+ and C/AI0-.  Then I am trying to get both side of the analog signal without any good results.

[Nathan-P]

you will need to be more specific.  I don't know what "without any good results" mean.  If you can provide screenshots and examples, that would be ideal.