When the pushbutton switch 80 is closed, {HEAD ~ the controller unit} 66 begins execution of {TAIL ~ the program} 200 at time T0 
When the pushbutton switch 80 is closed , { HEAD ~ the controller unit } 66 begins execution of { TAIL ~ the program } 200 at time T0
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH