MONITORING METHOD FOR OPTICAL ADM DEVICE, AND OPTICAL ADM DEVICE USING THE METHOD

PROBLEM TO BE SOLVED: To provide a monitoring method by which a more accurate fault recovery is made possible and to provide an optical ADM device using the method. SOLUTION: Power supply sections 13, 14 are configured in duplicate to supply power to optical switch control sections 7-10 so that optical switches 3-6 can continue their operations even when one power supply is faulty. Furthermore, an alarm signal to troubleshoot the power supply sections is synthesized (17) with a main signal and the resulting signal is transmitted to a transmission line so as to inform a terminal station device of fault information of the power supply sections. Thus, a relief job of the failure on the occurrence of the fault is executed without causing any mistake.