Doug Nix will be giving the third session in the three-part Introduction to Functional Safety seminar series at the IEEE Product Safety Engineering Society Virtual Chapter meeting.’ In this third…
Read MoreHow to do a 13849 – 1 analysis: Complete Reference List
Post updated 2019-07-24. Ed. As promised in previous posts, here is the complete reference list for the series “How to do a 13849 – 1 analysis”! If you have any additional resources you…
Read MoreISO 13849 – 1 Analysis — Part 8: Fault Exclusion
Post updated 2019-07-24. Ed. Fault Consideration & Fault Exclusion ISO 13849 – 1, Chapter 7 [1, 7] discusses the need for fault consideration and fault exclusion. Fault consideration is the process of examining the…
Read MoreISO 13849 – 1 Analysis — Part 7: Safety-Related Software
Post updated 2019-07-24. Ed. Safety-Related Software Up to this point, I have been discussing the basic processes used for the design of safety-related parts of control systems. The underlying assumption is…
Read MoreISO 13849 – 1 Analysis — Part 6: CCF — Common Cause Failures
Post updated 2019-07-24. Ed. What is a “Common Cause Failure”? There are two similar-sounding terms that people often get confused: Common Cause Failure (CCF) and Common Mode Failure. While these…
Read More31-Dec-2011 – Are YOU ready?
31-December-2011 marks a key milestone for machine builders marketing their products in the European Union, the EEA and many of the Candidate States. Functional Safety takes a positive step forward with the…
Read MoreInconsistencies in ISO 13849 – 1:2006
I’ve written quite a bit recently on the topic of circuit architectures under ISO 13849 – 1, and one of my readers noticed an inconsistency between the text of the standard and Figure 5,…
Read MoreInterlock Architectures Pt. 6 – Comparing North American and International Systems
I’ve now written six posts, including this one, on the topic of circuit architectures for the safety-related parts of control systems. In this post, we’ll compare the International and North…
Read MoreInterlock Architectures – Pt. 5: Category 4 – Control Reliable
Ed. note: I’ve made a few updates to this article since it was first published in 2011, with the most recent on 2020-05-11. – DN – The most reliable of the five…
Read MoreInterlock Architectures – Pt. 4: Category 3 – Control Reliable
This post was updated on 2020-03-28. Category 3 system architecture is the first category that could be considered to have similarity to “Control Reliable” circuits or systems as was defined in…
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