In the following series of blogs, we'll go back to basics and run down everything you need to know to get started in functional safety. We'll start with some more general terms and descriptions and make our way to more advanced material.
A SIS – Safety Instrumented…
IEC 61508 functional safety certification began in the 1990s. As I recall, the only organizations doing this work in those days were TÜV Rheinland and TÜV Product Services (now TÜV Sud). These two companies remain competitors.
Functional safety certification started with logic solvers. Some engineers and regulators at the…
I heard about a “safety certified” PLC in the late 1980s at an ISA SP84 standard committee meeting. The “logic solver” (as they later called it) was the focus of attention in the field of functional safety back then. Many engineers even said, “My system is safe because I…
In a marketplace where many of buyers of firmly committed to “proven in use,” many projects are still using 30 year-old logic solver designs. Proven in use is a valuable concept especially for field equipment where it is hard to evaluate how well a product design will…