Prevent Unexpected Equipment Start-Up with Defensive PLC Programming

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Power-On Safety Macro for the Crouzet PLC

Return to the Industrial Control and Automation Index for related content. All Programmable Logic Controller (PLC) programmers must pay attention to the corner cases. It is never enough to make the machine function. Instead, we must consider how the system will respond to unexpected events. One such event is the machine’s immediate action when the power is first applied. For this article we will focus on a class of machines that feature a physical ON / OFF switch. This physical switch may dir…