| 摘要 |
PURPOSE:To suppress an influence to a system to minimum when the trouble of a power source is recovered by holding a bypass condition until synchronization is established when the power source is recovered and cancelling the bypass when the synchronization is established. CONSTITUTION:When the power source is troubled, optical switches 11 and 12 are operated in a real line side and an input signal is outputted from an optical fiber cable through a bypass route 14 to the optical fiber cable. When the trouble of the power source is recovered, a relay 6 is turned off since the synchronization is not established in a synchronization detecting circuit 3. Then, the optical switches 11 and 12 are still in the real line side and the signal passes through the bypass route 14. When the synchronization is established in the synchronization detecting circuit 3, the relay 6 is turned on by a synchronization deciding output and the optical switches 11 and 12 are operated in a broken line side. Then, the bypass is canceled. |
