6225 DAQmx names for differential pair measurements

[THEEDGE714]

All,

I ran across this post when trying to find out if there was documentation to show which analog inputs are paired together and what name DAQmx commands call those pairs.

http://forums.ni.com/t5/Multifunction-DAQ/Device-Pinout-for-the-PCI-6225-in-Differential-AI-Mode/m-p...

The author posts a drawing that I think is correct, but it isn't an official NI document.  I'm looking for documentation that tells exactly what the name is for each pair when using them in a DAQmx command.  I know from the 6225 documentation that AI0 and AI8 are a pair, and AI1 and AI9 are a pair, etc., etc.   What I was trying to find, is documentation that shows what the name of each of those pairs is that I have to use in DAQmx calls when making a differential measurement.  Right now I am assuming that the AI0/AI8 pair is referred to as AI0 when making a differential  measurement.  I then have just followed the list of pairs in the user manual from left to right and top to bottom and started naming them from AI0 to AI39.  I was really hoping though that there was an official document that told what the names of each differential pair were. 

Can someone point me to the correct document or tell me that there isn't one and that my assumptions are correct?

Thanks!

Doug

[Danny_Funk · Accepted solution]

Doug,

There is not an official document similar to the one in the related post that shows the AI0+ and AI0-. The differential channel will always be referred to by the positive terminal. It doesn't matter which number of differential channel it is. For example the 9th differential channel uses AI16 as the positive terminal. Any configurations in DAQmx will need to be configured using AI16 in differential mode. The drawing that was posted isn't official, but is correct.

Regards,

Danny F