Responsive to the condition signal, {TAIL ~ the control part} controls {HEAD ~ the announcing arrangement} at the particular time instant 
Responsive to the condition signal , { TAIL ~ the control part } controls { HEAD ~ the announcing arrangement } at the particular time instant
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH