| 摘要 |
PURPOSE:To enable the processing of a fault of a toll transmission line rapidly and securely by composing a unit of an automatic fault detection part including a circuit which detects a combination of voltages, developed only when the transmission line gets out of order, by a logical level. CONSTITUTION:Transmitted and received voltages of the calling signal of a telephone channel are combined uniquely at the time of a fault. In the transmission- line supervisory unit of a control telephone repeater station, automatic fault detection part D regards as the fault of one transmission line a combinational state in which outputs of detector DETS for the calling signal of the telephone channel and detector DETR for the received signal are held at digital levels ''L'' and ''H'' respectively, and the fault information is supplied to operation part H, where it is combined with a signal inputted manually by a switch at need and then sent out to next-stage memory part M, but at this time, signals of operation part H and memory part M are multiplexed, so that the point, section, system, etc., of the fault will be displayed by lamps of display part P by flashing. |
