On Safety Fieldbus-based Interface Card For Nuclear Power Plant

Digital Instrument and Control (I&C) systems have been used successfully in Nuclear Power Plant (NPP), because of their great merits. It is essential to network communicate in I&C system. Fieldbus can be used in the bottom layer of general I&C system to interlink field devices, and also can be used to connect all kinds of functional computers to realize communication in a channel and between redundant channels, which are in the automatic control level of safety I&C system. So it is meaningful to develop communication interface to make field devices and functional computers be capable of communicating.To make nuclear grade digital devices based on software to have enough reliability, except for devices itself (including hardware and software) having high reliability, it also much lie on the system design, including its technical proposal and architecture etc., especially to follow all kinds of safety standards and design criterias. At the same time, in the develop procedure of nuclear grade digital devices, it is necessary to have special verification and validation (V&V) procedure, to check up and prove the performance and quality, and ensure that the requirements have been realized correctly.Therefore, the developed interface card has to satisfy both fieldbus communication requirements and nuclear grade requirements. This paper gives the overall design of nuclear grade interface card, particularly introduces how to apply the safety design criteria which bring forward by all kinds of standards and regulatory guides to the hardware and software development of nuclear grade fieldbus-based interface card. The developed interface card has function of self-monitoring due to the comparison circuit and the two-channel structure, so it is fail-safe, at the same time, the interface...