DIGITAL OUTPUT SUBSTRATE FOR MONITORING CONTROL OF PLANT AND ITS METHOD AND PLANT MONITORING CONTROLLER

PROBLEM TO BE SOLVED: To shorten a time required for the recognition and decision of the failure or defective part of an output system, and to realize the safe continuous operation of a plant. SOLUTION: A digital output register 103 outputs digital output signals S1 to SN of every channel from output channels C1 to CN to output destinations P1 to PN based on a command from a central control substrate 200. Disconnection detecting parts D1 to DN on each channel path individually monitors the power supply status of each channel to detect a disconnection status, and transmits the disconnection status detection information to a defective status change detection part 111. When any of the output channels C1 to CN and the output destinations P1 to Pn is disconnected, the defective status change detecting part 111 compares disconnection status detection information of this time and previous time, and when they are different, detects the changed contents as defective status change, and stores defective status change information showing the defective status change in a defective status change register 112. COPYRIGHT: (C)2007,JPO&INPIT