Implement a software safety system in the MTRotator CSC: if the error between the rotator and camera cable wrap gets larger than some specified amount, halt the rotator and put the system into a FAULT state. (This gives the camera cable wrap a chance to catch up, which makes it fairly easy to recover from this error).

This will rely on a new low-level rotator command that halts rotation and sends the low-level controller into the FAULT state. DM-28419

We would like to have in place by the time we add all the lines to the camera cable wrap and have to keep it in sync with the camera rotator. My understanding is that will occur sometime in February.

The desired limit is +/- 2.2 degrees. (I think this is also the specified limit for restarting the CCW if we pause it during an exposure. If so, one of these will have to change so we have some gap. But we'll worry about that if and when we decide we do want to pause the CCW during an exposure).