FAULT ANALYSIS ASSISTING SYSTEM FOR PROCESS CONTROLLER

摘要

PROBLEM TO BE SOLVED: To obtain a fault analysis assisting system for process controller by which the true cause of a fault is discovered in its early stages by trace back of changes of execution result data of each instruction of a control program. SOLUTION: Input value data and output value data of program instructions in the previous N cycles and the present of memory data to be used by the control program are stored in a storage means 18 by a data storage means 19 provided in a controller 10 and the execution result data of instruction of the control programs by every cycle is displayed by using the input value data and the output value data of the program instructions in the previous N cycles and the present fetched by a data reading means 22 by a data display means 24 provided in a maintenance device 11.