LINE INTERFACE CIRCUIT FOR SUBSCRIBER TERMINAL EQUIPMENT AND ITS CONTROL METHOD

摘要

PROBLEM TO BE SOLVED: To provide a simplified line interface circuit in which a dialer, a line interface section and a DC masking circuit or the like are not in duplicate for a voice terminal equipment and a non-voice terminal equipment for the execution of the emergency mode. SOLUTION: The circuit is made up of a line interface section 370 to make impedance matching with an exchange, a speech network 150 amplifying a voice signal between a telephone line and a voice terminal equipment 180, a MODEM interface 310 making impedance matching between a MODEM 107 of a non-voice terminal equipment and the exchange, a dialer 360, a switch section 350 selecting a voice path VP or a non-voice path NVP, and a control section 320 which checks a power on/off state of a control section 101 of the non-voice terminal equipment through a communication port 340, sends dial information to the dialer 360 from the control section 101 via the communication port 340 in the power on mode, allows a key matrix 250 to send the dial information to the dialer 360 in the emergency mode thereby controlling a switch section 350.