| 摘要 |
PURPOSE:To improve a system reliability by making it possible to switch automatically a transmission unit to a stand-by transmission unit at unit fault by adding a relay circuit to transmission units arranged in parallel. CONSTITUTION:Transmission units 3j and 3(j+1) consist of transmission circuit parts and connection parts, and relays rlj and rlj(j+1) of connection parts are operated according to turning-on and off of the power source of each unit 3. For example, when unit 3j is faulty, the driving power source of its relay and the relay driving power source of transmission unit 4j corresponding to unit 3j are turned off to supply transmission signals to stand-by transmission units 3(n+1) and 4(n+1) through cables 8 and 9. As the result, in case that one of transmission units arranged in parallel is faulty, the transmission unit is automatically switched to the stand-by transmission unit. |
