Simplyfying calculation of performance level

05 June 2009

The SISTEMA tool, developed by Germany’s BGIA organisation, helps to simplify calculation of the attained Performance Level (PL) of the safety related parts of a machine’s control system in the context of EN ISO 13849-1

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For many years the most common way of classifying safety related systems on machinery has been to use Categories as outlined in the standard EN 954-1 “Safety related parts of control systems”. This standard will be withdrawn at the end of December 2009. After this, EN 954-1 can no longer be used to provide a presumption of conformity with the European Machinery Directive.

A new standard to replace EN 954-1 has already been published and is available for use: EN ISO 13849-1:2008 “Safety of machinery - Safety related parts of control systems”. It provides a transition path from the previous five “Categories” (B, 1, 2, 3, 4) to the new classification of five “Performance Levels” (a, b, c, d, e).

In some circumstances it may be possible to use alternative standards such as EN/IEC 62061. However, the majority of designers will likely turn to EN ISO 13849-1 because the standard has been specifically drafted to provide a transition path for those who design systems to Categories per EN 954-1.

It covers all control system technologies (electrical, mechanical, pneumatic and hydraulic) and can be used either for a complete system or for a subsystem. for the next few years EN ISO 13849-1 is likely to become the most commonly used standard for machine safety systems.

What is the SISTEMA tool?
The SISTEMA tool, developed by Germany’s BGIA organisation, helps to simplify calculation of the attained Performance Level (PL) of the safety related parts of a machine’s control system in the context of EN ISO 13849-1. SISTEMA is available in English and German language versions and may be downloaded free of charge by following the link to BGIA’s website from www.discoverrockwellautomation.com/safety

How is Rockwell Automation supporting SISTEMA?
Data for Rockwell Automation machinery safety products is now available in the form of a library file to be used with the sistema calculation tool based on EN ISO 13849-1. You can download the library file free, when you register at www.discoverrockwellautomation.com/safety

The availability of this data library is evidence of the recognition by Rockwell Automation of the impact of EN ISO 13849-1 and other functional safety standards on industry. It is one of a number of activities and tools launched to provide help and guidance on how to deal with changes in legislation and standards in an ever more competitive environment.

The combination of the SISTEMA tool and the Rockwell Automation SISTEMA library will provide machinery and system designers with comprehensive support in the evaluation of safety in the context of ENI ISO 13849-1. Users are spared time consuming consultation of tables and calculation of formulae since these tasks are performed by the software. the final results can be printed out in the form of a multiple page report.