MISCONTROL PREVENTION METHOD AND PLANT MONITOR CONTROL SYSTEM

PURPOSE: To prevent the miscontrol output caused by the software abnormality in a processing mode and to improve the reliability of a plant monitor control system. CONSTITUTION: The control request information inputted by a man-machine input device 100 is received in the control reception process L1 and processed in a control information production process L2 and a control information storage process L3 in parallel to each other. In the process L2, a control instruction message is produced from the request information and then transmitted through an output process L5. In the process L3, a control object device is extracted out of the request information and stored in a control mode information management table. Then the device under control is notified after the start of the process L5. In the process L5, the rationality is decided based on the outputs of start requests of both processes L2 and L3 when they are ready. When the rationality is confirmed, a control output signal is outputted to a remote monitor controller 300. When no rationality is confirmed, the occurrence of abnormality is notified to a CRT 100. The abnormality is also notified when the start requests of both L2 and L3 are not ready after the process L5 is started at a prescribed time of a timer L4.