| 摘要 |
PURPOSE:To realize a diagnosis of a data transmission line without giving any effect to a decentralized computer control system under operation, by giving an output request from a central computer system and according to whether or not the change in the state of the signal input point caused by said operation is detected. CONSTITUTION:A signal output request is given from the #1CPU2 and through the side of a central master station 1 to the signal output point of a closed circuit consisting of a connection line 11 between a signal output device 9 and a signal input device 10 in a remote station 7. This request is transmitted to the station 7 if the data transmission line is normal, and the #2CPU8 drives the devide 9 to deliver the signal to the corresponding output point. On the other hand, this delivered signal is supplied to the device 10 to be detected by the #2CPU8 as a change of state at the corresponding signal input point. In case this detection is possible at the side of the station 1 and through a data transmission line 5, the data transmission line is diagnosed as it is abnormal. |
