How to control a simple voltage signal

[Ablarry91]

Hello all,

For testing purposes, I'd like to control my 24V CC power supply using LabVIEW to adjust the signal input.  I am using a NI PCI-6025e controller and running it with LabVIEW 2009.  The big issue that I have is that I can't seem to get a proper signal to generate.  I use the 'DAQmx Generate' function and create a DC signal with an offset, but regardless of what I adjust the offset to, my power supply pumps out much more current than I've calibrated for.  I hooked an ampmeter up to the signal output of the controller and found that it's delivering as much as .75A.  Any thoughts on how I can control this?  Thank you for the help.

-Austin

[Rodéric]

Can you post some code? Maybe you forgot to configure something.. have to you tried to control your hardware with MAX prior to attempt this with LabVIEW?

[Ablarry91]

Alright, as it turns out, the amperage reading was a mistake on my part.  There is, however, a difference in what my voltage power supply and NI controller are doing to my current supply.  I will deliver a 5v voltage signal using the voltage power supply, and my CC power supply responds perfectly.  If I deliver a 5v voltage using the NI controller, the CC power supply deals out a lot more than what I want.  Could there be a third variable that could be causing these varying outcomes that I'm not seeing?

[Broken_Arrow]

Check your ground, and make sure you are sending 0V and 5V (single ended) and not -5 and +5 (differential).