| 摘要 |
<p>PURPOSE:To attain mass production of the entire monitor systems and to reduce cost, by multiplexing a specific pulse train signal from each monitor slave device and using cable cores in common. CONSTITUTION:A receiving display device 1 for the centralized monitor is connected to monitor slave devices 3, 5, 7 via an aerial cable to be monitored. The devices 3, 5, 7 transmit respectively the specific pulse train signal to a pair of cable cores used in common at each transmission timing, when cable sections 2, 4, 6 are not faulty. Further, the monitor slave devices 5, 7 monitor subsequent cable sections 8, 9, 10, 11, and when they are not faulty, the corresponding specific pulse train signal is transmitted in the timing succeeding to the sound signal of the cable sections 4, 6. Further, if the receiving display device 1 cannot receive the specific pulse train signal for a period, e.g. once per 30sec, it is discriminated that a failure takes place in the monitor sections.</p> |
