IEC has published a Technical Report IEC/TR 62061-1 ed1.0 Guidance on the application of ISO 13849-1 and IEC 62061 in the design of safety-related control systems for machinery, which is available as a 38-page paper document or as a PDF file. It was prepared jointly by Technical Committee IEC/TC 44, Safety of machinery – Electrotechnical aspects and Technical Committee ISO/TC 199, Safety of machinery. Note that the Technical Report has also been published in parallel by ISO as ISO/TR 23849.
This Technical Report, which does not have the same status as an International Standard, contains the following sections:
- Comparison of standards
- Risk estimation and assignment of required performance
- Safety requirements specification
- Assignment of performance targets: PL versus SIL
- System design
According to the introduction, it is intended that this Technical Report be incorporated into both IEC 62061 and ISO 13849-1 by means of corrigenda that reference the published version of this document. These corrigenda will also remove the information given in Table 1, Recommended application of IEC 62061 and ISO 13849-1, which is provided in the common introduction to both standards and is now out of date. Subsequently it is intended that ISO 13849-1 and IEC 62061 will be merged by means of a Joint Working Group (JWG) of ISO/TC 199 and IEC/TC 44.
IEC/TR 62061-1 describes which standards can and cannot be used in different scenarios, though users should take care not to interpret the guidance too liberally. For example, the document states: "safety-related control systems based on media other than electrical can mean that the use of ISO 13849-1 is more appropriate." In addition, the document discusses the way in which one standard may be preferred over another; it gives the example of safety-related control systems of machinery used in process industries where safety instrumented systems are characterised in terms of SILs, which makes the use of IEC 62061 more appropriate.
A bilingual (English and French) version of IEC/TR 62061-1 ed1.0 is available from the IEC Webstore (priced CHF90 for the hard copy of CHF99 for the PDF) and ISO/TR 23849:2010 is available as a 14-page document, in either English or French, from the ISO website (priced CHF80 for all versions, hard copy or PDF). In addition, the report is published in the UK by BSI as PD IEC/TR 62061-1:2010, priced £124 or £62 for members of BSI.