TELEPHONE SET INCORPORATING MODULATOR AND DEMODULATOR

摘要

PURPOSE:To eliminate the need for mode setting operation by providing a control circuit setting automatically the mode in response to outgoing and incoming operation. CONSTITUTION:The data communication state is attained by operating a communication switch DCS 17 and a transmission data signal is sent to a telephone line from the transmission output Ds of a switching circuit CHC12B via a talking circuit TKC2 and a reception data signal is given to a reception input DR. An MODEM 11A has the 1st and 2nd modes in response to the operating carrier frequency and any mode is set in response to the mode selection signal MS from the control circuit CNT 16. The opposite mode is set at transmission and reception.