No compressor light on PCM, no compressor power, no CAN recognition of compressor

[ozrien]

Just release a new PCM User's Guide today...
http://www.crosstheroadelectronics.c...ol_system.html
...please read section 4.1 and follow the steps in order to help troubleshoot.

[adampaskowitz]

I'm not sure if you can tell what's what on this photo, but I think everything pretty much matches the wiring diagrams with the exception of the CAN cables, which I reordered to match GeeTwo's suggestion to have the CAN bus terminate at the PCM. Based on the new manual, it looks like we may have software issues.

[rich2202]

Originally Posted by adampaskowitz

II reordered to match GeeTwo's suggestion to have the CAN bus terminate at the PCM.

I think he suggested the two ends of the CAN bus are:

RoboRio
Power Distribution Board (with the Termination jumper set to On)

The Pneumatic Control Module would be in the middle.

That said, my team wired the CAN bus wrong, and it still worked.

[adampaskowitz]

You're right. Thanks. I'll switch it back, but I honestly didn't notice any difference between the way the robot responded when wired with either of those two arrangements.

[feverittm]

If your CAN is hosed (disconnected of wired wrong) you will get a red light on the PCM status indicator. Make sure everything is green.

Check your pressure switch. It should be a normally closed switch, so you should sense continuity (using a meter) across the wires going into the PCM.

If the status is green, and the switch if closed, but are the PCM indicator is flashing showly, and the compressor will not start, then it probably still disabled and you need to look into the code.

Please also remember the code suggestions given above. The compressor WILL NOT start unless either the compressor/PCM is defined in the code or there is some pneumatic element (solenoid) defined.

If you don't have any solenoids defined you will need to define the compressor:

public status final Compressor myCompressor = new Compressor(0);

We had this problem over the weekend and it took a few hours to figure this out.