ground analog output signals

[stekkie]

Hi,

I'm working with an NI USB 6211. I Have 16 analog inputs. I want to use them all but not differential, becaus thats not necesary. I'm measuring ac and dc signals. Now my questions is how do i connect my signals to the labview card to see the right signal. i'm working with optocouplers so i have ground problems when i use the AI GND input. When I place a resistor between gnd and the - input on differential measurments it's ok.

In the "labview help context" I saw the Measurement System Types and Signal Sources. (Diff, RSE, NRSE and Pseudodifferential) Can i use the NRSE with sense input? if so, how does the pc know i'm measuring that way?

The attachment shows my Vi. I've changed the 'Create Channel' from default to nrse, rse or pseudodiff, but than everytime my program doesn't working anymore (the basic dc/rms gives me errors)

thx in progress!

[Joris_D.]

Hi,

Let's first try to take a look at how your measurement setup needs to be. So in order for you to have more information on NRSE, RSE and DIFF measurements we have got this great article on the web:

http://zone.ni.com/devzone/cda/tut/p/id/3344

Try to take the time to read it and look if it can help you with your measurements. If you then still have problems with getting the program to work, just let me know and i'll try it myself. But first we need to make sure that our setup is correct for the type of measurement we want to do. Keep me posted!

[stekkie]

Thank you very much! I'll read it right away!