| 摘要 |
PURPOSE:To report fault detection to a user automatically to stop the use of a telephone set by controlling a control unit according to a program, which is stored in a storage unit previously and detects faults of check positions, to perform self- diagnosis automatically. CONSTITUTION:A public telephone set is provided with control circuit MCC which performs various kinds of control based on the detection output from each circuit which realizes the function of the telephone set, and a program to detect faults of check positions is stored in storage unit ROM1 connected to processor CPU1 of control circuit MCC. At every off-hook of hook switch H connected to I/O circuit I/O1, the program is read to perform automatically self-diagnosis of various kinds of function part connected to I/O1; and when a fault is detected, the faulty position is displayed automatically on display part DIS1 connected to I/O1 to report the fault to the user, thus stopping the use of the telephone set. |
