Alarm information transmission system of public telephone

Abstract

Abstract PURPOSE:To transmit contents of abnormality and self control number to a trunk line by detecting a call signal from the trunk line and opening and closing automatically a DC loop in accordance with the detected call signal so as to make a self-diagnosis. CONSTITUTION:A processor CPU7 executes a call processing program in a ROM15 connected through a bus 6, and makes a self-diagnosis and control corresponding to the opening and closing of the DC loop while it is accessing to data necessary for a RAM16. In case of incoming call, the DC loop is automatically opened or closed in accordance with the action of a contact gs<1> so that an incoming call detection circuit 3 can give a trigger-like incoming signal to a start circuit 9 and can drive forcibly a relay GS with the aid of a power source E2, and accordingly the CPU7 starts its action and first makes a self- diagnosis. When it detects abnormality, it transmits contents of the alarm information corresponding to contents of the abnormality and its own control number stored in the ROM15 to the trunk line through a line terminal 1 with the aid of an MF signal.

Inventors

• 👤 Yoshiaki Takeda
• 👤 竹田　義昭
• 👤 Toshiji Kinoshita
• 👤 木下　利治
• 👤 Osamu Kai
• 👤 治 甲斐

Bibliographic Details