| 摘要 |
PURPOSE:To always secure correct communications by intermittently transmitting terminal identification information and control information by means of a connector after the unoccupied condition of other equipment is confirmed, and transmitting the information by means of a telephone set only when receiving information and storage information coincide. CONSTITUTION:At the time of receiving, a receiving signal from a telephone line 1 is received by a connector 2, control circuit 14 confirms that neither of frequencies used for transmitting nor for receiving exist, thereafter, the information of a storage circuit 27 and receiving information are converted to a transmitting code, and it is transmitted with a weak wave from a transmitting antenna 7. At a telephone set 3, the code is received, and be connecting the pass of a receiving voice circuit 16 by means of a control circuit 24 when the receiving information and the information of a terminal identification information storage circuit 29 coincide, a receiving sound is generated from a receiver 15. At the time of responding, by making a condition input switch 30 into a service condition, the circuit 24 transmits response information and the terminal identification information with the weak waves different in frequencies from the transmitting antenna 1. At the device 2, after the response is confirmed, a line closing relay 13 is driven, a line 1 is captured, and a call condition is made. At the time of calling also, approximately the same action is executed. |
