| 摘要 |
PURPOSE:To improve the reliability with no increase of price for a loop type optical transmission system by providing a pair of optical transmission/reception units containing the light emitting and photodetecting elements connected optically to an optical fiber and capable of the bidirectional signal transmission, to each station. CONSTITUTION:A master station 1 is connected to stations 2 in a loop form via optical transmission lines. Optical transmission units 21 and 22 containing light emitting and photodetecting elements connected optically to an optical fiber and capable of the bidirectional communication are provided to each station 2. Then the light emitting element of one unit is connected electrically to the photodetecting element of the other unit directly or via a prescribed connection means. The reception signal is received by either one of both units, and this received signal is bypassed to the light emitting element of the other unit. While the transmission signal is transmitted via the light emitting element of at least one of both units. |
