| 摘要 |
PROBLEM TO BE SOLVED: To provide an alarm transmission method that can make an alarm notice with a simple configuration, without giving effect of distortion or the like on a signal to be substantially transmitted different from a conventional optical signal transmission system, and to provide an optical signal transmission system. SOLUTION: This system provides the alarm transmission method and the optical signal transmission system, where on the occurrence of a fault in one device, the one device informs other device about a fault occurred in the one device by decreasing an optical signal level of an opto-electronic converter 36', and the other device uses a light-receiving level monitor circuit 25 to detect that the level of the received optical signal has decreased, to recognize the fault occurred in the one device. |
