| 摘要 |
PURPOSE:To detect the status change of plant information in high speed, by executing the detection of fetching and its change of the status information of a plant with the hardware and providing a virtual input changed with a prescribed period. CONSTITUTION:When various control parameters are given from a computer program to a data input controller 5, the control for the fetching of information from an input module 6, operation of status change check and report to a main storage device 2 is made under the control of the device 5. On the status change table of the device 2, one bit reflecting the operating state of the device 5 is provided, a prescribed period is monitored with a built-in timer of the device 5, the timer is preset when the period is elapsed for a given time and the corresponding bit of the device 2 is set to 1. This bit is a bit representing the state of the device 5 and a virtual input to the program, and when this is at 1, the device 5 is in normal operating state. The virtual input bit is monitored with a monitoring period of the program longer than the monitor time period, and when this bit is at 0, the device 5 judge the state as failure to output alarm. |
