No PWM outputs

[kramarczyk]

I am running into a problem where no PWM output appears to be generated and consequently no drive motors are turning.

Background:
We are using Labview.
Jan 17 - I took the classmate and installed the Labview update then the DS update. I then reimaged the cRIO to v19. I tested this set-up on last year’s chassis and was able to drive the robot via joystick. The default project was built and deployed to the cRIO. Driving ability was again verified.

Jan 20ish – Last year’s chassis was stripped of its components and they were placed in cardboard box for re-use in this year’s chassis.

Feb 2 – Components are installed in this year’s chassis. Initial test demonstrated an inability to drive.

Symptoms:
No drive motors are turning (4 motor chassis). The Jags (4) are all flashing amber. The RSL is active, flashing in disabled and short flashing in teleop enabled.

Troubleshooting:
- Verified that the robot was enabled
- Verified that the robot had not been E-stopped
- Tethered the robot
- Verified that all PWM’s (4) are seated in the jags and DSC.
- Checked the continuity of all PWM conductors
- Replaced DSC
- Replaced cable between digital module and DSC
- Checked the interface between the cRIO and the digital module for bent pins or debris
- Attempted soft push of code from Classmate for 4 motor configuration
- Verified that gyro data returned to main front panel corresponds to gyro inputs (it changes when I manually turn the robot) and joystick inputs
- The PWM outputs reported to the dashboard correspond to the joystick inputs
- Reimaged cRIO to v19… again
- Created and soft pushed a default robot project without modification. Only the main front panel was opened to facilitate this.
- Verified that user watchdog is being fed. At beginning of Teleop VI

Conclusions to this point:
The issue is not downstream of the DSC. I think that simultaneous failure of 4 parallel components unlikely. The data stream through the digital module and DSC is functional by virtue of the correctly operating RSL. The error is not in my code as I have not written any. The DS is operating nominally by virtue of its ability to change the operation of the RSL. The cRIO is passing the RSL, gyro and joystick data back to the dashboard, so it appears to be operating nominally.

Next Steps:
<edit>Verify DCS supply voltage</edit>
Swap the digital module out with the spare
Repeat above with different laptop
Find a team that will allow me to borrow the cRIO to swap ours out

I am basically throwing parts at this to troubleshoot and running out of things to throw at it. It appears to be a system watchdog issue, but I don’t know how to address it. What am I missing.

Disclaimer: I am an ME and am not sure that electrons really exist.