| 摘要 |
PURPOSE:To decide on abnormality securely and to perform secure backup operation by allowing a sub-controller to execute two systems of software, providing an output module with a controller selection switch, and making one round of the backup operation covering the whole system at the time of a sub- controller failure. CONSTITUTION:A main controller 102 and feed water pumps 611, 621, and 631 are provided. The controller 611 has individual kinds of software A-BFP and C-BFP, the controller 621 has A-BFP and B-BFP, and the controller 631 has B-BFP and C-BFP respectively. When a decision making circuit 70 decides on the failure of the controller 611, the selection switch of the output module 613 is changed over to the side of the controller 621, which backs up the A-BFP. Each diagnostic module consists of an exclusive OR element, etc. so two modules are dissident at the same time in case of a controller failure unlike a double system, thereby deciding on the fault of a controller securely. |
