| 摘要 |
PURPOSE:To improve the efficiency of maintenance when one transmission system is troubled in a working and spare double-loop network by connecting the transmitting/receiving part of the spare system to the transmission line of the trouble system and switching the transmission side of a supervisory control unit in the spare system to manual operation. CONSTITUTION:At a normal time, selectors 21, 22 connect data receiving parts 12, 12' and transmitting parts 13, 13' inparallel respectively and are connected to a transmission line 0. When the line 0 is troubled, working transmitting and receiving parts 13, 12 are connected to a transmission line 1 so as to operate as an on-line and the spare transmitting and receiving parts 13', 12' are connected to the line 0. A selector 23 connects the transmitting and receiving sides of a supervisory control unit SV19 to the transmitting parts 13, 13' and the receiving parts 12, 12' respectively. A selector 24 switches the transmitting side of the spare system from the automatic side 26 to the manual side 27 to manually send a control signal to the transmitting part 13' and check the trouble status of the line 0. After finding a trouble position of the line 0, a maintenance man is dispatched to the trouble position to repair the fault, improving the efficiency of maintenance. |
