| 摘要 |
PURPOSE:To eliminate the need to use a switch signal containing a transmission line code error and apply a transmission line switch device for both wired and wireless transmission lines by transmitting the switch signal to both an in-use and a stand-by transmission line. CONSTITUTION:If a fault occurs on a transmission line 2, the transmission line fault is detected by terminating equipment and led in a transmission line switch device 17 to obtain switch information 5. The switch control circuit 33 of the device 17 sends a command to a transmission line switch circuit 34 according to the infomation 5, and a terminal station 19 is disconnected from in-use transmission lines 1 and 2 and connected to stand-by transmission lines 7 and 8. At the same time, transmit signal switch circuits 27 and 28 stop the signal from the terminal station 19 and perform switching to switch command information of signal generating circuits 25 and 26 to send the switch command information to an opponent station through both a transmission line 1 to be switched and a transmission line 7. When signal detecting circuits 29 and 30 of both in- use and stand-by transmission lines detect the switch command information in the switch device 17 of the same constitution of the opponent station, a circuit 33 operates a circuit 34 and then performs switching from an in-use transmission line to a stand-by transmission line. therefore, a switch signal which contains a transmission line code error need not be used. |
