| 摘要 |
PURPOSE:To ensure the changeover from a system with a fault caused therein to a standby system by disconnecting a data transmitter through an input/output optical fiber cable in a prescribed time after a power supply is interrupted. CONSTITUTION:When a power supply 13 of an active system is interrupted, a voltage detection circuit 14 sends an earthing signal to a timer relay 15 and it is operative after a prescribed time. When the relay 15 is active, its contact 18 is opened after it is closed, an optical switch 11 is disconnected from a battery 17 and power supply is terminated. A fault such as out of synchronism caused in a transmission line for the prescribed time is detected by other data transmitter of the active system and the changeover to the standby system is implemented. Then the system changeover at interruption of power supply is ensured by selecting a time constant of the timer relay to be a time or over when other data transmitter of one system detects a fault such as out of synchronism caused in the transmission line after the power supply of one system is interrupted and the changeover to the other system is finished. |
