Bidirectional signalling mechanism for interfacing computing devices to

Abstract

A signalling mechanism is used by a telecom adapter for interfacing a telephone line to a computer so as to exchange signalling information, such as pulse dialing information, ring indication information, or both. In accordance with one embodiment, the telephone line is sampled to produce a series of data samples. A signal is produced indicative of whether or not a ring signal is currently present on the telephone line, and the signal is combined with at least one of the samples in a single data unit. The single data unit is then transmitted to the computer. In another embodiment, a single data unit is received from the computer and separated into a data sample position and a pulse dialing control position. In one mode of operation the data sample position is converted to an analog signal; in another mode of operation, pulse dialing control position of the single data unit is used to perform pulse dialing. By transmitting the single data unit containing the ring indication signal to the computer and contemporaneously receiving the single data unit containing the pulse dialing (on-hook/off-hook)control signal in respective independent data streams an efficient bidirectional signalling mechanism is achieved, greatly simplifying pulse dialing and ring detection and allowing for relatively every compliance with international standards and regulations.