ANNULAR TRANSMISSION EQUIPMENT

摘要

PURPOSE:To secure the reliability of a loop network by monitoring centralizedly troubles of subordinate stations or transmission lines by a control station on the loop network and disconnecting trouble positions to reconstitute annular transmission lines if troubles occur. CONSTITUTION:If a control station 8 detects a trouble of subordinate stations 11-15 or transmission lines, one of dual annular transmission lines 9 and 10 is used to transmit a turn-back instructing signal to stations in the order from the subordinate station which is most distant in the signal transmission direction. When the turn-back indicating signal is turned back to the control station 8, this turn-back state is held. The other annular transmission line is used to perform the same processing, and these two transmission lines in the turn-back state are connected by the control station to reconstitute annular transmission lines.