PBX and works telephone system - has voice connections simplified by including extra lines and specified operations may be included

摘要

The private branch exchange and the works telephone system allows voice connections to be made to subscriber devices in other branch exchange parts. The system is simplified in terms of switching the voice path and in terms of the witching processes that the operator has to undertake. Specified lines are provided and assigned to certain parts of the composite system (e.g. the switching matrix). These lines are used to engage certain devices when certain specified operations are wanted.