| 摘要 |
PURPOSE:To monitor an in-use and a stand-by demultiplexing and multiplexing part on on-line basis and to improve the reliability of a communication circuit by utilizing effectively a stand-by circuit which is not used normally. CONSTITUTION:A DS1C type PCM signal is inputted to an in-use multiplexer M1C-DMUX and converted into two DS1 type PCM signals 1, which are inputted to and converted by an in-use multiplexer M12-1MUX into one DS2 type PCM signal, which is sent out. On the other hand, a switch SW1 is closed to input the DS1 type PCM signal to a stand-by M1C-1 demultiplexing part DMUX, which compares an output 2 with the output 1 of the in-use side, bit to bit, to monitor the in-use M1C-1 demultiplexing part DMUX. Further, the DS2 type PCM signal which is the output of a multiplexing part MUX of the in-use M12-1 is inputted to a stand-by M12-2 demultiplexing part DMUX by closing a switch SW2 and converted into a DS1 type PCM signal 3 to compare its output 2 with the output 2 of the M1C2, bit to bit, monitoring the in-use M12-1. |
