PURPOSE: To perform trouble diagnosis without intervention of the operator, by transmitting the diagnosis mode instruction from the central processing unit to the communication control part and by forming a transmission and receiving folded path by the communication control part and by transmitting and receiving diagnosis data by the communication control part, when abnormality of the line operation is detected.
CONSTITUTION: When operation abnormality occurs in a specific line, communication line control units 20-0W20-n, or terminal equipments 24-0W24-m, the first diagnosis mode is transmitted from CPU10 to communication control unit 14 through bus 16. When receiving this diagnosis mode, unit 14 analyses the diagnosis mode pattern in the encoder under the control of the microprocessor and forms a transmission and receiving folded path. Next, prescribed diagnostic data is transmitted to the path, and this data is received to perform trouble diagnosis; and if no trouble is detected, the second diagnosis instruction is transmitted from CPU10 to unit 14, and the folded path is released, and succeeding lines and equipments 24-0W24-m are diagnosed between unit 14 and equipments 24-0W24-m.
OKADA KENICHI
SASAKI SHINJI
| JPS53138606A | 1978-12-04 |