| 摘要 |
PURPOSE:To measure the attenuating characteristic of a optical transmission line during the operation of the optical transmission line without changing the connecting of the optical transmission line by measuring the signal strength of the light added with a data location signal from respective light emitting sources, corresponding to the data location. CONSTITUTION:In the optical transmission line to link plural control devices 1(1-1-1-n) with respective optical fiber cables 2, an optical signal Lc emitted, for example, from the control device 1-1 for a certain period by the time division is equally divided into Lc' by a star couple 3, and respectively makes incident through two pairs of the optical fiber cords onto the photoelectric converting device and the power meter of a characteristic diagnosing device 4. Since the inherent data location signal to identify the number of the light emitted control device 1 is supplied to the optical signal Lc, by calculating processing the optical signal photodetected by the characteristic diagnosing device 4, the number and the signal attenuating quantity of the passed optical fiber cable 2 are obtained. |
