A system for detecting movement of {HEAD ~ a forcer} of {TAIL ~ a motor} directed for effecting movement of a forcer in a first direction in response to command pulses 
A system for detecting movement of { HEAD ~ a forcer } of { TAIL ~ a motor } directed for effecting movement of a forcer in a first direction in response to command pulses
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH