KEY TELEPHONE LINE CIRCUIT TONE-ON-HOLD ARRANGEMENT

摘要

KEY TELEPHONE LINE CIRCUIT TONE-ON-HOLD ARRANGEMENT There is disclosed a circuit for generating tone signals from clocking signals present on each key telephone line circuit. The tone signals are transformer coupled onto the communication leads by an optional plug-in board arrangement. In present installations music-on-hold is provided by connecting an external music source to each line card. There is also disclosed an arrangement for utilizing the optional plug-in board to provide either tone-on-hold or music-on-hold by simply reversing a plug-in connector.