| 摘要 |
PURPOSE:To uniform a transmission speed before and after switching, by transmitting an order wire signal by another current system when one fault is generated at a current system, and transmitting a main signal and a switch controlling signal of the current system being generated the fault by a spare system. CONSTITUTION:When one fault is generated in the current system, another current system having no fault continues to transmit an order wire signal while superposing the order wire signal to a main signal. On the other hand, the spare system 1-0 transmits the main signal of the defective current system in stead of a specific pattern signal and superposes a switch controlling signal to the main signal. Since both current and spare systems superpose any subsignal, the same operation is performed practically and the transmission speed is not changed. |
