Eugene,
On my system I had no spurious data during hours-long tests as long as I had a Wait(.005) in each of the Continuous loops. Shorter Wait() times, e.g. 0.0045 did not work.
So the fix may be that easy, and most teams may have Wait(.005) or longer in place already. I did initially - it was only while experimenting with shorter wait times on our 2nd cRIO that I noticed the problem.
I had cross-posted to
http://decibel.ni.com/content/thread/2325?tstart=0 so there is more information there, but it is mostly intended to give a running start to the NI engineer who says he's going to look into it on Monday.
Good luck in San Jose.
Regards,
David
Daniel,
Thank you for your input. The thread topic is misleading at this point: the issue isn't the polling rate - mine was actually set at 50 Hz since I didn't read the value until deltaT > .02 .
The issue is the requirement to stop the task with a Wait() of a certain duration - or risk getting intermittent bad data of a very specific type.
I had thoughts similar to yours, so I ran add'l tests last night (see link above) which ruled out that explanation. Since zero values can be reported spuriously as well, (when the battery jumper is off), there is no "high" voltage on channel 8 to dissipate.
Regards,
David