Unexplained intermittent CAN / 2CAN Jaguar problems at GSR

[PhilBot]

Originally Posted by jhersh

Hi Phil,

That can happen if a Jag reboots or have a communication problem when you are configuring the Jag Position reference. I'm guessing if you had set the position reference again, you would have seen it fixed. Maybe your jags were browning out due to a low battery?

-Joe

None of the above.

When the problem first occured we changed batteries and re-booted several times. Changed batteries again later after matches were over. No effect.

The problem is that this "0.0 postion" error persisted for many reboots, debug download etc. and then just returned to normal and hour later.

As for the code...

The Jags are switched between "Voltage out" and "Position mode" each time a preset recall button is pressed (and held). Before the new mode parameters are loaded, the JAGs are disabled, and then re-enabled at the end. All of the JAG parameters (control mode, position source, pot turns, PI gains etc) are re-loaded, and the code checks for any errors and re-tries the command sequence 3 times if errors persist.

Note: We'd run into the occasional bad-command-write problem several days before shipping and had built in the retries. So it's pretty bullet proof.

Do you think accidentally sending the JAG an invalid "position value" (eg: a negative value for target position) could lock up the controller????

Phil.