| 摘要 |
PURPOSE:To continue status monitoring and abnormality monitoring by a sub- monitoring board even when functions of a central monitoring device get out of order by providing sub-monitoring boards that monitor each terminal equipment by address signals outputted from a transmission interface section and return signals between the central monitoring device on the signal transmission line and each terminal equipment. CONSTITUTION:An annunciator 9 which is a sub-monitoring board provided with a transmission interface section 10 that monitors transmission signals on a signal transmission line 1 and monitors each terminal equipment 2 by address signals and return signals is provided between the central monitoring device 3 on the signal transmission line 1 and each terminal equipment 2. The transmission interface section 10 always monitors transmission signals on the signal transmission line 1, and if there is any receiving signal, sends received terminal address and return signal from the terminal equipment to a CPU11. On receiving above- mentioned data, the CPU11 lights up an LED at a position corresponding to the terminal address in a display section 16 by setting above-mentioned return data as a state of operation of the terminal side if the terminal address is registered in a data conversion table memory 14. |
