Embedded Control / PLCs / Sensors

PLC vs. programmable relay

Can a simple application still benefit from a programmable logic controller, or is a programmable relay all it needs?

By Mike Bacidore, editor in chief

A Control Design reader writes: I have a small test system that I want to put error proofing on. The sensors are actuated in a very simple extend-and-retract sequence. The application only has four inputs and three outputs. Because it’s such a simple application, how do I decide whether to use a PLC or a programmable relay?


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REAL ANSWERS: What should you use — PLC or programmable relay?

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