EN ISO 13849-1, a guide to the transition from EN 954-1

This guide has been written to help machine builders and system integrators make the move to designing safety-related control systems according to the requirements of EN ISO 13849-1, which is due to replace EN 954-1 at the end of 2011 (see this article: EN 954-1 extension confirmed as two years. In addition, the booklet will help machine specifiers and those who are modifying or upgrading machinery and need to apply the new functional safety standard for machinery safety.

Following an introduction, the book provides an overview of the basic differences between the old and new standards, and introduces Sistema, the free software utility from the German organisation BGIA (Institute for Occupational Safety and Health) that performs the calculations necessary for designing systems to EN ISO 13849-1.

The bulk of the guide works through the process necessary for designing systems in accordance with ISO 13849-1, with clear diagrams to help explain the points being made. Where appropriate, references are made to Sistema so that readers gain an insight into the tool (which has been described by some users as not particularly intuitive). Topics covered include:

• System architecture
• Reliability data
• MTTFd (mean time to dangerous failure)
• Methods of data determination
• Diagnostic coverage (DC)
• Common cause failure (CCF)
• Systematic faults

At the back of the booklet is an explanation of how machinery safety affects machinery manufacturers (OEMs) and end users differently. As part of this there is an interesting discussion of the way complying with legislation (and standards) can raise unexpected challenges such as reduced machine performance, additional costs and harder maintenance - and how these can be addressed or avoided by choosing the right supplier of safety components (and appropriate support services). There is, as you might expect, also a brief overview of the safety products and services available from Rockwell Automation.

For copies of the free guide to EN ISO 13849-1 and the transition from EN 954-1, go to the Rockwell Automation Safety Solutions Portal.