REPEATING DEVICE FOR OPTICAL NETWORK

PURPOSE:To prevent a system-down by providing two sets of repeating circuits in a repeating device for a bus system optical network, and providing a defect deciding controlling means which monitors the repeating circuit, and switches and stops the repeating circuit at the time of the occurrence of a defect in the respective repeating circuits. CONSTITUTION:The repeating device 1 is provided with the repeating circuits 10a, b, and these circuits are provided with a defect detection circuits 106a, b respectively, and when the defect occurs in the circuit 10a, it automatically switches it to the circuit 10b. The circuits 106a, b are due to detect the defect by the system to decide whether the input output signals of the circuits 10a, b coincide with each other or not. When a discordance continues for prescribed time in the circuit 106a is decides that it is defective, and informs it to a switching circuit 110, and the input gate 107a of the input terminal IN-A of the circuit 10a is closed by the signal from the circuit 110, and the input gate 107b of the input terminal IN-B of the circuit 10b is opened. Because the output signals of photoelectric converting parts 12a, b are respectively inputted to the opposite side circuits 106a, b of each other, even if the defect is generated in the converting parts 12a, b, the circuits 106a, b can detect said defect.