Telephone Line Monitor

AI-5120 - Advent Instruments Inc. (AI)

The AI-5120 is a compact device designed for monitoring and analyzing signals present on the telephone line. By sensing the voltage present on the telephone line it detects and measures ringing, DTMF & pulse dialing, FSK (Bell 202 and V.23) signals, line polarity reversals, and open switching intervals (OSI). Working in conjunction with the TRsSim software on a PC, the AI-5120 becomes a valuable tool in analyzing and debugging Caller ID and SMS (Short Message Service) data transmission. Like an oscilloscope, it can capture and display waveforms showing various signals present on the telephone line.