| 摘要 |
PURPOSE:To allow a caller to recognize the end of its call and to allow a person in house to notice that a device installed in the house is under control from a visiting place by a telephone call and to obtain a margin time for talking by providing a means for sending an alarm tone to a telephone line even when the personnel in house is going to apply control while the device installed in the house by telephone from the visiting place is under control. CONSTITUTION:A synthesized voice tone is sent several times, someone resides in the house, the operation of a remote controller is informed to the called party, and it is utilized that a DC circuit is not opened while the synthesized tone rungs continuously and the telephone control is informed to the person in house through the blinked LED regardless of the residence mode. Then the time margin for talking is given if the person notices it soon and lifts up the handset.
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