| 摘要 |
PURPOSE:To supervise the state of a center without providing an external supervisory device by transmitting a supervisory signal to a centralized supervisory maintenance center at each prescribed period from a gateway station exchange and supervising whether or not a response signal is returned within a prescribed time. CONSTITUTION:The gateway station exchange GWS transmits the supervisory signal to a centralized supervisory maintenance center CMOC via a common line signal channel L1 at each prescribed period. A processor COM of the CMOC receiving the said supervisory signal returns the response signal to the GWS via the L1. The GWS receiving the said reponse signal decides that the CMOC is operated normally. If the GWS does not receives the response signal within a prescribed time after the supervisory signal is transmitted, it is discriminated that the CMOC is in abnormal state and a hardware alarm representing that the CMOC is in abnormal state is transmitted via an alarm transfer line L2. |
