Reducing CAN network noise

[jwakeman]

Doing some testing on a prototype setup this weekend we encountered occasional comm faults in the CAN network that would cause the motors to shut off momentarily. We were running the motors continuously and every 30 seconds to 1 minute they would glitch. Each time this happened if we connected to the jaguars with BDC-COMM we could see a couple of comm faults had accumulated. The wiring was a bit of a mess on this setup (and we also discovered we had no isolation between the CAN network and the power electronics of the Jaguar as I described in this thread) so we suspected some noise on the network. We are using brand new jaguars, with a 2CAN and the can cables that came with the 2CAN. We had already checked the pins in the sockets on the Jaguar. So I am confident the noise/faults aren't coming from faulty cables or network termination or anything of that sort.

We later moved the cRIO, PD board, Jaguars and CIM motors to a table top (no metal frame, no other garbage to induce noise) and ran the same test where we were continously running the motors. This time no glitches, no comm faults, i.e. no noise. So we think if we do a quality job with wiring (as we normally do) on our final robot installation we can probably avoid noise issues. We plan to run signal wires separately from power wires, twist wires in pairs to cancel noise, we may even wrap the power leads in tin foil.

The question is have any other teams encountered noise on their CAN networks and found unique solutions (they would like to share) such as noise filtering circuits, cable routing techniques, etc? Replies with theoretical solutions are OK but I am really looking for things teams have done that worked.