[mswalker]

We used CAN in 2011 for four motors without any problem. In 2012 we linked 9 Jaguars (about half each black/tan) with CAN. We had quite a few problems with loss of motor function and increased latency. I believe that the connections and wire integrity were the main issues. We spent several hours one night testing all the cables and connectors to make sure we had good wires and good connections. That worked for a while but then the latency came back. The latency showed up in a lack of responsiveness to the controls - e.g. stuttering instead of driving ahead smoothly. In each case it would take a lot of time to trace the entire daisy chain to try to figure out where we were having a problem. When we watched the network when we had problems we would see a large number of communications errors, e.g. can't find the address. We could usually fix the problems by replacing a cable or working on a jack but it all took time.

After our practice sessions at regionals we replaced the CAN connections with PWM. We didn't have any issues with control latency after that.

CAN seems to be the way to go but doesn't seem sturdy or reliable enough at this point.