We have a device, made by Teltone, that connects to a regular analog phone line. It has an audio output that plugs into a workstation and a serial port that also plugs into a workstation. The serial port accepts "Hayes"-style AT commands, such as "ATH" for hanging up or "ATD" for dialing. Hayes AT command, an introduction
Signal pins are 1-4-2-5-3 for DIN connector. Send the command sequence
ATZ1 - reset to default ATE - echo off ATV3 - use word return code ATS0=1 set to auto-answer AT*R2 after each call to get audio out to the phone lineSet to auto answer after given number of rings