TIME-DIVISIONAL CONNECTION SYSTEM FOR A PLURALITY OF DIGITAL COMMUNICATION CIRCUITS

A time-divisional connection system for a plurality of digital communication circuits for connecting time-divisionally, for each communication circuit in a characterwise manner, between one and the other of each pair of two-way digital communication circuits by means of four-wire terminal equipment. The system includes a detector for detecting time-divisionally, for each communication circuit, whether or not a time-serial character exists at one of the input and output terminals of the four-wire terminal equipment for each communication circuit, and means responsive to the output of the detector for interrupting one of two paths from the input terminals to the output terminals of each communication channel in the four-wire terminal equipment during the duration of the detected character or characters in order to prevent an undersired sending-out or receiving of the detected time-serial character signal.