PURPOSE: To perform monitoring and control easily without increasing the number of couples of transmission lines by switching the monitor part and control part of a monitor station upon occasion, and connecting power sources for them so that their polarities are opposite between the monitor part and control part.
CONSTITUTION: A changeover switch 13 is connected normally to the monitor part side including a power source 41 and a current detecting circuit 5 at the monitor station 1, and a monitoring voltage is applied from the power source 41 to a terminal equipment 2 through a monitor control line 3. The control relay 9 of the equipment 2 is disconnected from the circuit by a diode D14 and does not operate, a resistance sending circuit is formed of diodes D151 and D152 to vary a circuit current by opening and closing contacts 71 and 72, and the monitor station 1 detects that by the circuit 5 to obtain monitor information on the terminal equipment. When the switch 13 is placed on the lower side corresponding to the control part side and a push button 6 is depressed, the D14 conducts by the control voltage of a power source 42 and the control relay 9 is energized to perform control, turning off the diodes D151 and D152.
SAITOU TOSHIO
YUSA HIROSHI
DOI SHIYUNICHI
NIPPON TELEGRAPH & TELEPHONE
| JPS5129375A | 1976-03-12 | |||
| JPS5164313A | 1976-06-03 |
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