Machinery Safety 101

Understanding Safety Functions: the start/restart function

Car engine start/stop button

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.

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Understanding Safety Functions: the Safety-related stop function

A stop sign - A red octagon with a white border, and white block text reading STOP.
This entry is part of 3 in the series Under­stand­ing Safety Functions

The most used safety func­tion on machinery is the safety-related stop func­tion. The require­ments dis­cussed in this post are not gen­er­ally applic­able to pro­­cess-related stop func­tions unless the pro­cess and… 

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Manual reset using an HMI

A Siemens HMI displaying control functions and data.
This entry is part 2 of 3 in the series Under­stand­ing Safety Functions

Ques­tion: Can a safety-related stop func­tion, for example, be reset via a graph­ic­al object rep­res­ent­ing a reset but­ton on an HMI? The short answer: No, with an excep­tion. Read on if you’d like… 

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