| 摘要 |
PURPOSE:To enable precise fault separation without being controlled by distance resolution precision by using the testing light of a wavelength reflected in a wavelength dependent type reflection circuit and the testing light provided with a pulse waveform interrupted by a BPF built in a subscriber terminal of the wavelength transmitted through the wavelength dependent type reflection circuit. CONSTITUTION:First, by using the testing light of the wavelength for which reflected light is generated when the testing light is made incident on a short wavelength transmission type reflection circuit 8 generated in a light pulse testing device 40, a fault separation test is performed. Then, by using the testing light provided with the wavelength for which the reflected light is not generated when the testing light is made incident on the circuit 8 in the testing device 40, the fault separation test is performed. Thus, the interruption of testing signal light by the circuit 8 installed in front of the optical receiver 4 of the subscriber terminal 7 is performed by the BPF 5, and the fault separation relating to a fault point 20 is precisely performed. |
