| 摘要 |
PURPOSE:To operate an optical local area network by providing an optical coupler and a control signal detector, supervising normally a command from a central equipment and excluding a failed terminal station equipment automatically. CONSTITUTION:If a terminal equipment supervised by a central equipment 7 is failed, a bypass mode command signal from the equipment 7 is inputted to a control signal detector 5 via an optical coupler 1 and an optical receiver 3 through an optical fiber cable and a changeover instruction of an optical switch 2 and a power interruption instruction of the equipment 6 are outputted. A switch 2 is connected to the output side of the coupler 1 and the network is in the bypass mode where the equipment 6 is disconnected. When the fault of the equipment 6 restores, a bypass mode release command is outputted by the equipment 7 and the detector 5 releases the switch 2. |
