| 摘要 |
PURPOSE:To easily segment fault parts by providing a fault occurrence check means which checks the occurrence of faults in a transmission part by means of the detection output of a surplus bit check circuit and specifying the fault parts. CONSTITUTION:In a control signal addition means 260 provided on the precedent stage of an electricity/light conversion circuit 250 in the transmission part of an intermediate repeater 200, information that parity check is executed from the parity check circuit 240 in the reception part is received, and the information is overlapped with the surplus bit of a main signal in an incoming line. On the other hand, the surplus bit check circuit 600 in the reception part of a terminal repeater 100 detects information that parity correction is executed. In the fault occurrence check means 120 provided on the precedent stage of the electric/optic conversion circuit 110 in the transmission part of the terminal repeater 120, repeater the occurrence of the fault is checked in the transmission part of the terminal 100 by the detection output. As a result, whether the fault is occurred in the transmission part can be decided and it can be decided to have occurred in an optical transmission line if the fault does not occur in the transmission part. |
