| 摘要 |
PURPOSE:To select valid data out of redundant information just through the function of a selecting device by deciding whether the information can be used or not for plant control through the selecting device to recognize the number of valid data without obtaining the number of valid data from the number of CPUs. CONSTITUTION:When a plant generates a phenomenon to be controlled, the information on the phenomenon is sent to a transmission line by a system together with a unique number (phenomenon occurrence number). If a function A works with said phenomenon, the CPUs 8 and 10 which can execute the function A supply the relevant information to carry out the function A. Then the CPUs 8 and 10 add the phenomenon occurrence number equal to the input data to the processing result of the function A. Thus data is sent to a selecting device via a transmission line. The selecting device controls the allowable time covering from the generation of the phenomenon to the output of the control information and counts the processing results of the function A obtained within said allowance time in the form of valid data to perform decision by majority. |
