| 摘要 |
<p>PURPOSE:To prevent the transmission of a monitor control signal from being affected even in the middle of turning back by inputting a communication signal to a monitor control signal branching part as usual when a signal on a transmission line-side is turned back and transmitting a transmission signal to a transmission line as usual when a signal on a device-side is turned back. CONSTITUTION:At regular time, a transmission-side selection part 3 selects a signal from a monitor control signal insertion part 2, and a reception-side selection part 6 selects a signal from a reception interface 5. At the time of turning back the signal on the transmission line 10-side, the transmission-side selection part 3 and the reception-side selection part 6 select the signal from the reception interface 5. Since a reception signal is inputted to a selection control signal branching part 7, the monitor control signal is extracted and branched as usual. At the time of turning back the signal on the device-side, the transmission-side selection part 3 and the reception-side selection part 6 select the signal from the monitor control signal insertion part 2. Thus, turning- back to the device-side is conducted, and the transmission signal is transmitted to the transmission line 10 as usual. Then, the monitor control is signal to an opposite station is prevented from being stopped.</p> |
