| 摘要 |
PURPOSE:To bracket a fault point instantaneously by monitoring a synchronism fault through an in-use device and a stand-by device which is made hot simultaneously, and collating their results with each other. CONSTITUTION:Information from an incoming-side circuit Wi is passed through the multiplexing part 2, channel 3, and demultiplexing part 4 of an in-use system, and sent out to an outgoing-side circuit Wo through a switching circuit 5. At this time, the multiplexing part 2', channel 3', and demultiplexing part 4' of a stand-by system are made hot. Multiprocessing synchronizing devices 10 and 10' are connected to the channels 3 and 3' to detect a synchronism fault; pieces of fault information are collated with each other by a collating circuit 11, and the outputs of the demultiplexing parts 4 and 4' are collated with each other by a collating circuit 12. When an exchange is normal and a fault occurs on the transmission line, outputs of the circuits 11 and 12 are both 0, and the devices 10 and 10' judge in which circuit the fault occurs from a time slot number. When the transmission line is normal and a fault occurs to either of the channels 3 and 3', the outputs of the circuits 11 and 12 are 1. When a fault occurs between either of channels 3 and 3' and the output side, the output of the circuit 11 is 0 and the output of the circuit 12 is 1. |
