Redundancy Digital Output Module Design Based on 1oo2D Architecture

Considering that most current nuclear power manufacturers have implemented diagnostic technologies for high reliability digital output modules to ensure the correctness of digital output signals, such technologies can only confirm the fault status of the digital output channels and report failures. however, Unable to predicted failures in advance to transition faulty modules into a safe output state. This paper discusses the design of a redundant digital output module based on a 1oo2D architecture. By paralleling the output channels of mutually redundant digital output modules and providing a communication channel for status interaction between redundant modules, the design achieves controllable status of redundant output channels in the event of a single module failure, ensuring safe output of redundant channels. Additionally, based on fault analysis, static and dynamic diagnostic circuits are added to detect short circuit and open circuit conditions of the relay contacts executing the digital output signals. This ensures that the downstream load equipment will not fail to act or act incorrectly when a single module fails, and allows for the prediction of failures in advance. Finally, the design's feasibility is validated through functional testing and fault injection testing.