SPECIAL NUMBER CALL SYSTEM

PURPOSE:To attain emergency communication by registering and storing only a dial number except a line wire calling dial number as to a specific line wire telephone set so as to have only to dial a number known in general. CONSTITUTION:A special number expansion memory 4 registers and stores only a dial number except a line wire calling dial number '0' as to a specific line wire telephone set 8, e.g., only a dial number '119' when the specific telephone set 8 is the telephone set of, e.g., a fire station. In hooking off a receiver and dialing a special number, e.g., '119' of a fire station by an extension telephone set 7, a line circuit 6 detects a call and a dial and its information is sent to a central control unit 2. Then the central processing unit 2 collates the number with a number registered in the memory 4, and sends its number information to a trunk 5 when they are coincident and the trunk 5 calls the line wire telephone set 8 connected to an NTT line 9 with said number.