| 摘要 |
<p>PURPOSE:To simplify the circuit constitution by connecting a transmission end of a standby line in advance in parallel with an optional transmission end switch of an active line, connecting the transmission end of the standby line in parallel with the transmission end of a faulty line when other active line is faulty and connecting the transmission end of the standby line in parallel with the transmission end of the restored active line when the faulty line is restored. CONSTITUTION:The transmission end of a standby line 0 is connected in parallel with an optional line (n) of N active lines (1-N) in advance and a transmission input signal is sent therethrough. When a line (m) of the active lines (1-N) is faulty, a line switching controller 100A at the sending end allows a sending end switch n1 connected in parallel with the sending end of the standby line 0 to release the parallel transmission, allows a sending end switch m1 of the active line (m) having the fault to connect the sending end of the standby line 0 and the transmission input signal is sent to the standby line 0. When the faulty active line (m) is restored, a receiving end switch m2 is selected to output a reception output Dm of the normal active line (m) externally. In this case, the sending end of the standby line 0 is connected in parallel with the sending end switch m1 of the restored active line (m) as it is. Thus, the circuit constitution is simplified.</p> |
