How can I tell if my PCI-6052E has bad channels?

[Nate001]

Hi,

I am using a PCI-6052E DAQ. I am measuring a differential voltage from two points on a circuit card I am working on. When I run the VI I've written, I see the voltage I am expecting (6.34 volts) but then it will jump to 10 volts or -10 volts and then back to the expected voltage (6.34). It dose this repeatedly at a random rate.

The DAQ will do this on 5 of the 8 differential channels I have available. The other three hold steady at their expected voltages.

Any suggestions on how to verify the DAQ is operating properly?

Thanks in advance.

[devchander]

One question i ask

Is this observed even when you scan the channels from MAX or a continuous acquisition example VI??

Or is it observed only on the vi you have written??

[Nate001]

I see this same thing when I look at the signal using MAX.

How ever I have not tried the signal from the suspect bad channel on a suspected good channel. I will give that a trie and see what happens.

[devchander]

Do try that and let us know the result

[Nate001]

I was able to move the input to a different channel and the problem moved with the input, thus indicating my problem is with hardware I have connected.

In the mean time, I found an article entitled "Internal Analog Input Channels for Self-Diagnostics or the Monitoring of Analog Output Voltage" (found here: http://digital.ni.com/public.nsf/allkb/6c77b1884f5bbee8862569e3005be30e) that I was able to use to verify that my DAQ is indeed good.

Having read back through the user's manual again, I discovered that the power supply I was using had isolated outputs. Using a biasing resistor to AIGND solved my problem. My signals are measurable and stable where I want them.

Thanks for your input. I do appreciate it.