[dmcguire3006]

Since the A/d converters for the Voltage & Current sensing are embedded in the MCU, and since they are sampling at 15Ks/s (see data sheet), and hoping that the design engineers applied appropriate lowpass filtering before the A/D converters, I don't thing that the erratic nature of voltage & current will be a significant factor. I did notice that the accuracy of reading voltage is +/-.3V and +/-1A, meaning the accuracy in power measurement in 0.3 Watts, but this should be insignificant given the average power consumption of the robot would be approx 300W.

Another advantage of CAN is this mode (from the Black Jag data sheet):

"Position Control Interface
This set of commands is used to configure and operate the motor controller using position control mode. The motor control position commands consist of enable/disable of position mode, setting the motor position, setting the PID loop control parameters and setting the source for detecting position. Position control is managed through the use of an externally attached optical encoder combined with the motor controller’s encoder inputs or through the use of a potentiometer."

So it looks like the CAN interface can make the CIM (or whatever) motor, attached to an position encoder or potentiometer, operate as is it were a servo: the user can command the angular position and the Jag will close the servo loop to seek to the desired position.