Secretarial answering system with distributed processing

Abstract

A secretarial answering system for use with a switching system which includes a plurality of subscriber telephone stations each equipped with a buzzer, and a secretarial telephone station equipped with an audible signalling circuit and a plurality of lamp and switch pairs. A first processing unit periodically scans line circuits to determine changes in the busy, idle or ringing status of the subscriber stations. A second processing unit converts status and line identification information from parallel to serial format, and transmits it to the secretarial station via a link bus protocol for packetized messages. The secretarial station then provides visual and audible indications of subscriber station status. The secretarial station transmits a switch initiated directed call pickup or a call transfer message to the switching system, and a buzzing requested message to the second processing unit. The directed call pickup message identifies the subscriber station whose incoming call is to be transferred to the secretarial station for screening. The call transfer message identifies the subscriber station which is to receive a screened call. The buzzing requested message is converted from serial to parallel format by the second processing unit and is then sent to the first processing unit. The first processing unit is thus informed to cause the called subscriber station's buzzer to provide an audible signal indicating that the current incoming call has been screened by a secretary.