Intermediate line circuit for telephone PBX - has special selectors and switching multiples which can be used only by exchange translations when all other devices are engaged

摘要

When one or all switching multiples to which the exchange translations and internal connecting circuits (BI JV1, JV2 ...) are connected, are engaged, switches switch over to the central switching device. There are selectors for connection to a PBX extension, and/or to one or more switching multiples which are pref. assessable only in the direction to a PBX extension. The selectors can be used only by exchange translations. A typical exchange circuit may be used for 50 subscribers. There are 5 coupling field groups (A) with several cross-connections to 4 coupling field groups (B).