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