negative voltage reading???

[BP1000]

I've got a PXI-6224 and I'm reading multiple voltages.  When I run a test in MAX all the voltage read what I expect.  Now I have set up a LV program to read the voltages and I'm getting about half of the numbers correct and about half are negative values and the values aren't even the negative of the number I am expecting (eg, expecting 1.8 getting -1.3, expecting 1.25 getting -3.38).  Any ideas what's going wrong?

[devchander]

In MAX what terminal configuration are you using?? RSE??NRSE?? DIFF??

Use the same terminal configuration in LabVIEW application vi

from the pic, it is clear that you have left input terminal configuration as default

[BP1000]

Ah ha, I've got it set up as RSE.  I was completely missing that aspect of it.  I've read up on it and I'm still not sure how to specify my terminal configuration in LV.  How do I do this?

Sorry if the question seems silly, I'm just getting started with LV and applying it to my application.

Thanks!

[Dennis_Knutson]

The terminal configuration is set with the DAQmx Create Channel which you don't have in the image you posted. Is there some reason you are using the build array and Flatten Channel String instead of just the Create Channel function?

[BP1000]

Isn't the 2nd DAQmx  box in the image a create channel?   I also found how to specify RSE on that and now I'm getting the results I was expecting.

LV doesn't allow me to wire several channels directly into the creat channel thats why I was using the build array and flatten.  Does that make sense or is there a better more efficient way to handle this?

[Dennis_Knutson]

Oops, you're right. You did have the Create Channel function there. I was so confused about the use of the Flatten Channel function that I missed it.

Of course Create Channel allows for multiple channels. The syntax is Dev1/ai0:x for sequential channels or Dev1/ai0,Dev1/ain for non-sequential channels. When you create a physical channel control or constant, the Browse option gives you the ability to select multiple channels.