| 摘要 |
PURPOSE:To eliminate the use of a signal for information on the service interruption and its transmission channel and to simplify the constitution of the titled transmission system, by transmitting the information excepting for the service interruption information from the demander side in the form of analog signals and then transmitting the service interruption monitor information according to the presence or absence of said analog signal. CONSTITUTION:A monitor part 1 is set at the demander side of electric power of a monitor information transmission system to monitor the electric power equipment. The part 1 is connected to a transmission part 2 via a data transmission line 4, and the monitor data is transmitted to a subscriber telephone circuit 5. The part 1 also contains a signal conversion part 11 connected to each sensor 3, and the signals sent from the sensors 3 are processed by a linear wave detecting circuit 112, a filter 113, a limiter 114 and a PWM modulator circuit 115 of the part 11. These processed signals are transmitted in the form of analog data after PWM modulation performed by the signal sent from an oscillation part 12. A signal detecting part 22 of the part 2 monitors the presence or absence of said analog data. When no analog data is detected, the service interruption information is transmitted to a master device via a telephone circuit 5. Thus the constitution is simplified for the monitor information transmission system. |
