Industrial safety news including functional safety, safety instrumented systems (SIS), IEC 61511, IEC 61508, ISA 84, ATEX, HAZOP
November 2, 2007
(Opinion Column)
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Integrating Control and Safety – Where to draw the line? Irvine, California, USA – November 5th, 2007
Robin McCrea-Steele, TÜV FSExp
Invensys-Premier Consulting Services
New digital technology now makes it feasible to integrate process control and safety instrumented functions within a common automation infrastructure. While this can provide productivity and asset management benefits, if not done correctly, it can also compromise the safety and security of an industrial operation. Cyber-security and sabotage vulnerability further accentuate the need for securing the Safety Instrumented System (SIS).
In this opinion column we will discuss good engineering practices in integrating control and safety in a secure manner, while maintaining independent layers of protection. Potential benefits and side effects of the different approaches will be highlighted.
Future Trends in Safety Instrumented Systems The central role of the safety-PLC forces companies to decide on the logic solver integrity class (e.g. SIL 3) taking into account the current risk levels to be reduced by the SIS, as well as future higher risk levels. This article describes the future expectations with regards to the requirements and application of dedicated safety-PLC’s.
