| 摘要 |
PURPOSE:To make the operating times of a centralized and an individual power supply device coincident with each other by detecting a feeding to a transmission line so as to control information processing and communication processing. CONSTITUTION:An output transistor(TR) of a feeding detection means 5 of a communication controller a4 an individual feeding terminal equipment 3 is turned on with a power supply 1 applied, and a voltage 0V is applied to a terminal 8. Then a transmission means a7 detects power-on and informs it to an information processing unit a9 and the communication processing is started based on the feeding from a power supply means 10 and data transmission reception are implemented among terminal equipments 3, 11, 12. With the power supply 1 turned off, the TR of the means 5 is turned off, a voltage V is applied to the terminal 8. Thus, the means a7 detects power-off and informs it to the processing unit a9, then the communication processing is stopped and the terminal equipment 3 takes the same state as the other centralized terminal equipments 11, 12. Thus, the operating period of the centralized feeder is made coincident with that of the individual feeder and thereby checking the feeding state and the connection state. |
