first encoder means for binary encoding a signal obtained from {HEAD ~ said first means} with {TAIL ~ a predetermined voltage level} 
first encoder means for binary encoding a signal obtained from { HEAD ~ said first means } with { TAIL ~ a predetermined voltage level }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL