Method and apparatus for sharing a single telephone line between a

Abstract

A device and a method for directing incoming calls from a single input telephone line to either a facsimile machine, a data modem, or a telephone is provided. The device and method provide for 'isolating' both a facsimile machine and a data modem until after a predetermined delay period, thus preventing them to answer the call. If a person or answering machine has not answered the call within the delay period, an off-hook condition is simulated to the input telephone line, thus 'answering' the call. The signal on the input telephone line is then detected. If the signal includes a DTMF digit, various functions are performed including resetting internal variables. If a facsimile handshake signal is detected, the facsimile machine is rung with a ring simulator. The facsimile machine can then read the incoming handshake signal and proceed in a conventional fashion. If, however, neither of these two signals are detected, and a telephone answering device has not answered the call, the data modem port is rung with the ring simulator. The data modem will then begin receiving the transmitted signal in a conventional fashion. If the call is answered during the delay period provided by the invention, and the transmission is a facsimile handshake signal, the call is automatically transferred to the waiting facsimile machine.