[Aren Siekmeier]

The first list Ether gave are optical encoders, giving a tick count for how many times the shaft has spun around. This is an incremental measure of rotation. However, the second list are all magnetic encoders that sense the absolute orientation of a permanent magnet mounted to the shaft. This is an absolute measure of rotation. Both have their uses.

I'm not entirely sure how these encoders (or any others) hook up to the Jag, or how the Jag uses the data for whatever speed or position control you off board to it, but it all works somehow.

If you're going to run any PID on a two (or more) motor gearbox, however, you probably have to do it on the cRio, because there is yet no way to sync the speed controls off of one feedback sensor. I believe this is on the TI's agenda for a new Jag firmware.

The 2CAN is significantly faster than the serial bus (about 5x, I believe). This may not be an issue, but when we tried CAN this year on a serial bus, our 7 Jags plus some calls to the limit switches on one of them bogged down our CAN bus quite a bit because the serial bus just can't get that many packets through. I'm quite sure the 2CAN would eliminate this problem (for another $200...).

Jaguars on a competition robot are only limited by the number of motors. Every year past (I can't imagine this would change) you can only have one motor per speed controller, one speed controller per motor, and motors have been pretty strictly specified, with up to 13 this year. Very few FRC robots ever have more than 10.