The occurrence of the pulses are compared digitally resulting in an analog control signal for {HEAD ~ the adjustment} of {TAIL ~ the work piece drive} 
of
The occurrence of the pulses are compared digitally resulting in an analog control signal for { HEAD ~ the adjustment } of { TAIL ~ the work piece drive }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL