Full scale noise on PXI-5102 Digitizer

[VI_Joe]

Occasionally, we have test failures associated with excessive noise on a PXI-5102 Digitizer.  When this happens, I open MAX and run a test panel on the PXI-5102.  The test panel shows +/- 5V of noise on both channels.  If I remove the cables from both BNC inputs of the PXI-5102 , I still see the noise on the test panel.  Next, I power down the PXI, reseat the PXI-5102, and the problem goes away.

Has anyone experienced this?  Should I be doing some sort of routine maintenance to prevent this from happening?

Thanks in advance.

[Brandon_G.]

Hi VI Joe,

That is very interesting, the +/- 5 V noise is the input range limit of the 5102. 

1. Can you run the 5012 in NI-SCOPE and see if the noise level changes with the volts/div setting?

2. Have you seen this problem occur in another slot?  Can you try another slot and see if the problem follows the card?

3. What happens if you short out an input on the card, so that you have 0V across the input?  Do you still see significant noise?

4. Once you reseated the card and the problem goes away, how long does it take for the problem to arise again?

There isn't any routine maintenance that needs to be done other than calibration, but even if calibration wasn't performed you would not see that type of behavior.

Thanks!

Brandon G

[VI_Joe]

Unfortunately, I can't perform any of your suggested debug techniques now that the problem has been cleared.  We have several PXI stations here and we see this problem maybe once every 3 or 4 months.  I can tell you that this last time, I first noticed the problem on a VI that was displaying a 5102 measurement.  The vertical range was set for 32 and the display was completely filled with noise (32V max shown using a x10 probe).  I can't remember if I've seen this on another slot.  But when this occured last, I did check the other 5102 in teh system (two 5102's per system) and it showed no signs of noise.  The 5102's are plugged into slots 2 & 3.  I didn't short out the inputs, but I did remove the cables attached to the 5102 and the MAX test panel still displayed the noise.  For whatever it's worth, these systems are powered by power conditioners.

[Brandon_G.]

Hi VI Joe,

I am wondering if the issue you are seeing could be caused by heating and cooling of the board.  The next time, this issue occurs you may want to try turning your PXI fan to the 'high' setting and seeing if after a few minutes the issue goes away.  I would also try the other troubleshooting steps I mentioned before so we help narrow down on the problem.  Please keep me posted!

Thanks!

Brandon G