| 摘要 |
PURPOSE:To control terminal equipments in a center equipment, by transmitting control commands from the center equipment to terminal equipments in the communication system where the center equipment and plural terminal equipments are connected by a loop optical transmission line. CONSTITUTION:A center equipment 10 and plural terminal equipments 11-13 are connected into a loop by an optical transmission line 14. The center equipment 10 is provided with a controlling part 41, a transmitting part 16, a receiving part 19, an electrophoto transducer 17 and a photoelectric transducer 18, and terminal equipments are provided with control parts 38-40, photoelectric transducers 23-25, electro-optic transducers 26-28, optical switches 32-34, and optical branching equipments 35-37, respectively. In each terminal equipment, when the power is turned off, the optical switch is switched as shown by the solid line, and the terminal equipment is by-passed. When the power is supplied by a power source operating part, the optical switch is switched as shown by the dotted line, and the terminal equipment is connected to the line. |
