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