| 摘要 |
<p>PURPOSE:To improve the operability and the maintainability by detecting the abnormality between terminal stations in a terminal station device by frame step out of a main signal to give an alarm and detecting the abnormality between a terminal station and a repeating station or between repeating stations in a repeating installation by frame step out of an auxiliary signal to give an alarm. CONSTITUTION:The repeating installation converts an inputted optical signal to an electric signal by an optical-electric signal converting circuit 12 and decodes a CMI signal to an NRZ signal by a transmission line decoding circuit 10. Simultaneously, the auxiliary signal is detected by violation, and auxiliary signal frame bits sent from a counter device are detected by an auxiliary signal frame synchronizing circuit 14 to confirm the frame synchronization, and the result is displayed on a synchronization settlement display circuit 16. Meanwhile, the terminal station device converts the inputted optical signal to an original main signal through an optical-electric signal converting circuit 12 and a transmission line decoding circuit 10. The auxiliary signal is detected, and auxiliary signal frame bits sent from the counter device detected by an auxiliary signal frame synchronizing circuit 14 to confirm the frame synchronization, and the result is displayed on a synchronization settlement display circuit 16.</p> |
