| 摘要 |
PURPOSE:To supervise a lighting load in a broad range and over a long distance by connecting a plurality of terminals to a control supervisory means through a transmission line of closed loop. CONSTITUTION:A plurality of terminals 12 which control and supervise a lighting load 15 are connected to control a supervisory means 14 by a transmission line 13 of closed loop. Then, a terminal 12 is addressed form the control supervisory means 14 to make such controls as ON/OFF of the lighting load 15 connected to that terminal 12, and the supervisory information indicating the operating condition of ON/OFF of the lighting load 15 is returned to the control supervisory means 14 from the terminal 12 through the abovementioned transmission line 13. Transmission lines 13a-13h which form such a closed loop can be made up of a single one by use of, for example, optical fiber, etc. They are especially advantageous when the lighting load 15 is provided in an open place over a long distance. It is thereby possible to reduce the number of signal lines and control and supervise many lighting loads. |
