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 mandatory application of EN ISO 13849 – 1 and ‑2. As of 1‑January-2012, the safety-related parts of the control systems on all machinery bearing a CE Mark will be…
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 today, 6‑Dec-18. – DN – The most reliable of the five system architectures, Category 4 is the only architecture that uses multiple-fault tolerant techniques to help ensure that component failures do not result in an unacceptable…
Read MoreInterlock Architectures – Pt. 4: Category 3 – Control Reliable
Category 3 system architecture is the first category that could be considered to have similarity to “Control Reliable” circuits or systems as defined in the North American standards. It is not the same as Control Reliable, but we’ll get to in a subsequent post. If you haven’t read the first three posts in this series, you may…
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 and controls designer, I had to somehow wrap my head around the whole concept in ways I’d never considered. If you’re trying to figure out risk…
Missing MTTFd data
Dealing with the huge information void that exists while trying to complete reasonable control reliability assessments is a major challenge for every engineer or technologist tasked with this activity. Here are a few thoughts on what to do now, and where things may be going…
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 number of standards (say, more than 10), the publication of another new standard or Technical Report isn’t news – it’s business as usual. The question…
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.
Read MoreNew Guide to Applying ISO 13849 – 1 and IEC 62061
IEC and ISO have published a new guide to help users select between ISO 13849 – 1 and IEC 62061. This new Technical Report will replace Table 1 in both standards.
Read MoreSafety is Good Business
In this excellent article from Rockwell Automation’s The Journal, Mike Miller and Wayne Solberg explain how EN ISO 13849 – 1 and EN IEC 62061 mesh for machine builders.
Well worth the read in my opinion!
The Journal: Safety is Good Business – Marshall & Solberg
Interlock Architectures – Pt. 2: Category 1
This article expands on the first in the series “Interlock Architectures – Pt. 1: What do those categories really mean?”. Learn about the basic circuit architectures that underlie all safety interlock systems under ISO 13849 – 1, and CSA Z432 and ANSI RIA R15.06.
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