| 摘要 |
PROBLEM TO BE SOLVED: To facilitate the inspection of an optical transmission system by transiting the central processing unit of a slave machine to maintenance mode, and outputting an optical signal for maintenance for a fixed time to perform the inspection and judgment. SOLUTION: When an optical field bus apparatus 3 (A1) is used, for example, an optical signal power measuring optical signal can be transmitted from the optical filed bus apparatus 3 (A1) for a fixed time by transmitting a command of transition to maintenance mode from a host apparatus 1 to the optical field bus apparatus 3 (A1). Consequently, the host apparatus 1 can inspect whether the received optical signal from the optical field bus apparatus A1 exceeds a predetermined power level or not by use of an optical power meter 7 by connecting an optical fiber 51 to the optical power meter 7 after transmitting the command of maintenance mode transition to the optical field bus apparatus A1. |
