In 1995 CEN published an important standard for machine builders – EN 954 – 1, Safety of Machinery – Safety Related Parts of Control Systems – Part 1: General Principles for Design. This standard set the stage for defining control reliability in machinery safeguarding systems, introducing the Reliability categories that have become ubiquitous. So what do these categories mean, and how are they applied under the latest machinery standard, ISO 13849 – 1?
This article expands on the first in the series “Interlock Architectures – Pt. 1: What do those categories really mean?”. Learn about the basic circuit architectures that underlie all safety interlock systems under ISO 13849 – 1, and CSA Z432 and ANSI RIA R15.06.
This article explores the requirements for safety related control systems meeting ISO 13849 – 1 Category 2 requirements. “Gotcha!” points in the definition are highlighted to help designers avoid this common pitfalls.