How can a host PC know if the RMP motors are not powered?

[Segway]

When the CUs shutdown as a result of a fault and/or estop request, there should be no traffic on the CAN bus with the exception of the ESTOP message from the deuce to the CUs (message id 0x412).

Over USB, a heartbeat message will continue from the deuce board which will indicate that no data has been received over the CAN_A or CAN_B channels. No additional data should be transmitted over USB.