TIME DIVISION FULL DUPLEX COMMUNICATION SYSTEM

PURPOSE:To speed up and make efficient the full duplex communication system, by making full duplex communication digitally and in time division, through the use of only one line of two-line type among data signal transmission and reception devices. CONSTITUTION:A zero return double current type pulse is transmitted to the secondary winding of a transformer 3A to two-wire lines 5 corresponding to a transmission data signal SDA with a prescribed period. This signal is received at a pulse reception circuit 2B through the primary winding from the secondary winding of a transformer 3B. Since a non-window pulse inversion WPB is given to this circuit 2B, the zero return double current pulse only incoming during ''1'' is detected, and a reception clock pulse RCB and a reception data RDB are demodulated and outputted. The pulse RCB is made delayed 4 and becomes a transmission clock pulse SCB of the transmission circuit 1B of a telephone terminal B. The transmission data signal is transmitted from the circuit 1B to a controller 5 similarly.