To provide a mask circuit in {HEAD ~ a control device} which controls each signal, enables {TAIL ~ the timing system} to exactly perceive a swimmers touch 
To provide a mask circuit in { HEAD ~ a control device } which controls each signal , enables { TAIL ~ the timing system } to exactly perceive a swimmers touch
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH