Ladder logic uses switch or relay contacts to implement Boolean expressions. In years past, ladder logic was made possible with discrete relays and was sometimes termed “relay logic.” Today most ...

When a PLC is used primarily to replace relays, timers, and counters, it's hard to beat the simplicity and usefulness of ladder diagram programming. Their ability to accept programming in ladder ...

Some control applications are too small or simple to use even the smallest PLC, but still need more flexibility than a simple relay. That's why engineers at Schneider Electric, Palatine, Ill.

Relay Ladder Logic (RLL), a graphical programming language based on relays, is simple to learn and easy to use. While earlier versions of International Parallel Machines Inc.'s software were DOS based ...

There are various approaches to developing programmable logic controller (PLC) applications using experimental techniques. Modifying existing PLC ladder logic programs is another common approach ...

There are many vendors and sources of PLCs: Automation Direct, FactoryMation, B&B Electronics, and yes, even eBay, among others. I will use the Click PLC available from Automation Direct as an example ...

In the first two installments of this series, we discussed whether or not an old transmitter was even worth fixing, followed by some techniques I ve used to repair high-voltage power supplies. This ...

On the surface, a programmable logic controller (PLC) might seem like nothing more than a generic microcontroller, perhaps outfitted to operate in industrial settings with things like high ...