6 hours, 4 mentors and 2 students couldnt figure out whats wrong with our relays

[kavisiegel]

Originally Posted by Mark McLeod

Have you tried connecting one of your other DSCs to see if the problem follows the board or occurs with any DSC?

You can do replacement tests on the cRIO module and on the cRIO slot as well to eliminate each step in the electrical chain.

Yeah, we tried 2 empty DSC's.

We also replaced the entire cRIO, using the modules from the old one. We then swapped slot #4 and #6, then took out #6 all together, then re-imaged in case anything was dependent on #6

[billbo911]

I know this is a shot in the dark, but we are having very similar problems, so I thought I would throw in my $.02.

By any chance are you running your compressor code in the timed loop section, either 10ms or 100ms?
If so, by any chance is the camera not currently hooked up?

Here is why I ask.
In the past we have had lots of trouble when our camera cable had come unplugged and we had a lot of robot code that was included in the same loop. The huge amount of load placed on the system with bad or no data from the camera prevented the rest of the code from completing. What I am wondering is if the same thing is happening now. We currently do not have our camera plugged in, but the code is still running. The vision code runs in the same "Frame" as the periodic loops. Could the camera errors be preventing the periodic loops from updating the output to the relay controlling the compressor?

I will be investigating this around 4:30pm PST today.

[billbo911]

OK, the camera was not the problem, but our code was. We now have it working!
The root cause was that we had set the relay definition as "Forward Only" in the Begin.vi. Changing it to "Both Directions" did the trick.

Here is my posting with a picture of what fixed it for us.


Edit: It looks like this is a known issue. Thanks to Joe Ross for pointing this out.