| 摘要 |
PURPOSE:To release a loop by leaving a path through which a signal of a release instruction is sent into a loop island even when the loop island is formed in mistake. CONSTITUTION:A loop is formed through loop forming ports 9, 9' between amplifiers 10 and 11 through the changeover of switches 4, 4'. When the two amplifiers are taken in a loop island, an external signal is interrupted and the reception of any signal from optical cables 40, 41 or 42, 43 is disable and the transmission of a command from signal input ports 7, 7' or signal output ports 6, 6' is disable. In this case, the loop island is released by inputting a loop release command to either of monitor control circuits 5, 5' via signal input ports 8, 8' connecting to the amplifier of the adjacent system in normal operation. |
