[MikeE]

At the risk of being redundant and rehashing the problems that are described above and on other threads, we've identified two distinct problems with our Java / CAN system (we're using the BlackJag serial/CAN bridge).

1) Intermittent initialization failures. This always occurs as a failure of all Jags so we initially checked the cabling/termination extensively on the bridging Jaguar. Typically a power cycle of the robot fixed the issue, but sometimes a cRIO reboot worked and sometimes it persisted over multiple reboots. It seemed to be more prevalent on our practice bot than competition bot, but that may be due to a side effect of a higher frequency of power cycling on practice bot. We had one total failure to move in eliminations at Chesapeake which may have been caused by this problem. We didn't get the memo which provoked some teams to abandon CAN in favor of PWM. We will be implementing the initialization retry work-around in code on the practice bot once it's been de-cannibalized. I hope the potentially imminent NI patch solves the root cause.

2) Stuttering. This is not strictly a CAN problem because we see all outputs disabling briefly. Occurs both in autonomous and teleop, and looks quite dramatic when pneumatic solenoids are briefly disabled and our arm mechanism looks to be giving a round of applause. Originally appeared to be a code problem in teleop, but refactoring didn't solve the problem. I don't believe we've seen the problem in competition. We will check for Jags reporting a powercycle in case this is a voltage problem, although I don't think that's likely.