Machinery Safety 101 » Functional Safety

31-Dec-2011 — Are YOU ready?

Doug Nix — Fri, 30 Dec 2011 17:59:20 +0000

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. …

Inconsistencies in ISO 13849–1:2006

Doug Nix — Thu, 10 Nov 2011 13:30:02 +0000

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, the diagram that shows how the categories can …

Interlock Architectures Pt. 6 — Comparing North American and International Systems

Doug Nix — Mon, 03 Oct 2011 12:30:09 +0000

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 American systems. This comparison is not intended to draw conclusions …

Interlock Architectures – Pt. 5: Category 4 — Control Reliable

Doug Nix — Mon, 26 Sep 2011 12:30:41 +0000

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 exposure to risk. This post will delve into the …

Interlock Architectures – Pt. 4: Category 3 — Control Reliable

Doug Nix — Mon, 19 Sep 2011 12:30:13 +0000

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 …

Missing MTTFd data

Doug Nix — Mon, 13 Sep 2010 12:30:41 +0000

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...

IEC/TR 62061–1 Reviewed

Doug Nix — Wed, 08 Sep 2010 12:30:08 +0000

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 …

Interlock Architectures – Pt. 3: Category 2

Doug Nix — Tue, 24 Aug 2010 13:23:15 +0000

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.

New Guide to Applying ISO 13849–1 and IEC 62061

Doug Nix — Fri, 06 Aug 2010 13:51:28 +0000

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.

Safety is Good Business

Doug Nix — Wed, 28 Jul 2010 20:00:34 +0000

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