| 摘要 |
PURPOSE: To perform a division test without influencing main signal transmission in a testing system at the time of the division test of an optical transmission line. CONSTITUTION: In a transmitter for which a host station and a subordinate station transmit main signals by the optical signals of a first wavelength λ1 by the optical transmission line 1 in an outgoing direction and the optical transmission line 2 in an incoming direction, constitution is performed so as to transmit test signals by the optical signals of a second wavelength λ2 2 by the optical transmission line 1 in the outgoing direction and the optical transmission line 2 in the incoming direction. Then, when channel alarm is detected on a host station side or a subordinate station side, data for the test are sent out from a testing device 19 provided on the host station side to the subordinate station side by the test signals, the test signals in the outgoing direction are looped back to the incoming direction by a loop circuit 15 on the subordinate station side, the data for the test are received by the looped-back test signals in the host station and thus, the division test is performed to the subordinate station. |
