The master processor includes {HEAD ~ means} for generating {TAIL ~ a periodic pulse} which is detected by the slave processor 
The master processor includes { HEAD ~ means } for generating { TAIL ~ a periodic pulse } which is detected by the slave processor
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH