This is a first On Thursday, 2023-04-27, ISO published ISO 13849-1:2023, the 4th edition of the dominant functional safety standard for machinery. Usually, I would be the first to tell you that you should buy the standard as quickly as possible and start using it immediately. Today is not a normal day. As Command Module…
Read MoreUnderstanding Safety Functions: the start/restart function
After the safety-related stopping and the reset functions, the start/restart function is the next most common. Without a start/restart function, there is no way to make the machine do what it’s supposed to do. If you’re designing a machine control system, you need to understand this function.
Read MoreISO 13849-1 Analysis — The 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 think readers would find helpful, please add them in the comments.
Read MoreISO 13849-1 Analysis — Part 8: Fault Exclusion
Post updated 2019-07-24. Ed. Fault Consideration & Fault Exclusion ISO 13849-1, Clause 7 [1, 7] discusses the need for fault consideration and fault exclusion. Fault consideration is examining the components and sub-systems used in the safety-related part of the control system (SRP/CS) and making a list of all possible faults. This is a non-trivial exercise!
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 to design safety-related parts of control systems. The underlying assumption is that these techniques apply to the design of hardware used for safety purposes. The remaining question focuses on the design and development of safety-related software that…
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