| 摘要 |
PURPOSE:To improve the operating ratio and the reliability of the system, by instructing a station to be monitored to fold the transmission network by a monitor station when a fault occurs. CONSTITUTION:When a fault occurs, a monitor station 2 instructs all stations A-D to be monitored to fold dual transmission networks in every station. This instruction is executed first in the nearest station A, and the station A transmits its own station address to the monitor station 2. The monitor station 2 stores the address of the station A and releases folding of the station A. Though the monitor station 2 expects that a station B will tramsmit the address, the station B cannot transmit the address to the monitor station 2 because of the fault between stations A and B. The monitor station 2 detects that the address is not transmitted from the station B, and the monitor station 2 discriminates the occurrence of a fault between stations A and B and instructs the station A to fold the transmission network. Simultaneously, the similar processing is performed for stations D and C to ensure the line. |
