Telecommunication installation with two sets of function keys - enables calls to be made from subsidiary installation via main switchboard to subscriber in public network

摘要

The subsidiary installation (7) is connected by two wires (8,8') to the main installation (1) which has connections (3,3') to the public switched network and (9) to other subscribers. Up to eight system telephones (6 bar) having lines (5) to the subsidiary installation are equipped with two function keys (H1,H2) for access to the main switchboard and two function keys (A1,A2) for the public network. This enables a subscriber in the public network to be called directly without recourse e.g. to earthing keys or an exchange code. Destination keys (Z) eliminate the dialling of numbers. ADVANTAGE - Desired subscriber can be reached more rapidly and reliably by simplified operation.