Implementation of a safety instrumented system

We have developed the ProSafe-RS Safety System as a core safety instrumented systems of Yokogawa. This system complies with safety integrity level 3 (SIL3) of the IEC61508, and has been certified by a third-party certification body as conforming to the standard. In addition, it has high availability and nice features so that it provides comprehensive solutions to users who implement integration with process control systems. The main feature of the ProSafe-RS hardware is the application of dual microprocessor technology, not only to the processor module, but also to the I/O module. This paper describes the technologies to achieve high safety integrity level such as dual redundant technologies and diagnostics.