| 摘要 |
PURPOSE:To use one telephone circuit for both data communication and telephone, by constituting a telephone set in such a way that a MODEM automatically responds upon detecting a calling signal, and when a prescribed signal is detected within a prescribed time thereafter, the circuit is switched to the talking side, ringing tone are produced, and then, after hook-up is made the telephone set operates as an ordinary telephone set. CONSTITUTION:A prescribed signal detecting circuit 7 is provided, and when a prescribed signal is detected within a prescribed time even if a circuit is connected with a MODEM side after a call arrives, the circuit is not disconnected, but switched to a telephone set side. At the same time, ringing tone and produced and after the receiver of the telephone set is lifted up or a switch corresponding to off-hook is depressed, the telephone set operates as an ordinary telephone set. Therefore, a calling subscriber calls the communication control equipment of the called subscriber, and even after the MODEM responds, the calling subscriber can switch the MODEM to the ordinary telephone set by transmitting a prescribed signal and can talk with the called subscriber. When the prescribed signal is not sent, the set operates as an ordinary MODEM and can be used for data communication also.
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