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 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 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…
Read MoreUnderstanding Risk Assessment
When people discuss ‘Risk’ there are a lot of different assumptions made about what that means. For me, the study of risk and risk assessment techniques started in 1995. As a technologist…
Read MoreIEC/TR 62061 – 1 Reviewed
Why You Need to Spend More Cash on Yet Another Document Standards organizations publish documents in a fairly continuous stream, so for those of us tasked with staying current with a large…
Read MoreInterlock Architectures – Pt. 3: Category 2
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.
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