IEC 61131-3 in safety applications

The majority of safety related systems within process applications rely on plant or process specific software to define their functional safety operation. Previously, many of these systems have employed bespoke programming languages and environments. However, IEC 61131 is increasingly expected, and its absence maybe a barrier to entry for some sectors. The paper presents an overview and introduction to elements of IEC 61508 as a summary of the safety requirements, how some of these requirements are addressed by an implementation of IEC 61131-3, and the practical experience of addressing these requirements whilst adopting a commercial off the shelf package.