| 摘要 |
PURPOSE:To prevent the increment of load of a computer due to the abnormal operation of a contact by stopping the internal state value of the computer when the ON/OFF frequency of an apparatus exceeds a fixed value within a regulated time in a plant monitoring system. CONSTITUTION:A contact input processing part 1 enters a contact state from a process in each second, and if a change or more is generated from the preceding state, trigers a contact change processing part 2. The processing part 2 trigers a prescribed program in a relation processing part 3 in accordance with an item generating the contact state change. A contact operation monitoring part 4 monitors a contact state change generating item in each 20 seconds. Namely, the changing frequency of the same contact number is counted up, and when the count value exceeds the regulated value for deciding contact abnormal operation, an input stop flag is set up to request contact input stop and output an alarm. |
