PRIVATE BRANCH EXCHANGE CAPABLE OF RESPONDING TO DID DIL INCOMING

摘要

PURPOSE:To respond to a call regardless of the busy state of an extension telephone set of the call destination by controlling a switch means to temporarily connect a signal tone sending means by a connection control means at the time when a DID(direct in dial) DIL(direct in line) call comes to one extension terminal and the extension terminal is busy. CONSTITUTION:When a DID DIL call comes to one of extensions (extension telephone sets) 1 and 2 from a trunk line 10, a connection control means (B board controller) 6 controls a switch means 9 and temporarily connects a signal tone sending means 4 to this extension terminal 1 or 2 to send a DID DIL incoming indicating signal tone if this extension terminal 1 or 2 is busy. When the extension terminal 1 or 2 to which the DID DIL call comes responds to the call by hooking or dialing operation, the switch means 9 is controlled to connect the trunk line 10 to the extension terminal 1 or 2. Thus, one of extension terminals 1 and 2 receives the call from the trunk line 10 while being busy and alternately speaks with the other of terminals 1 and 2 and the trunk line 10 or these three parties speak with one another.