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 ...

The programmable logic controller (PLC) is a microprocessor-based system that accepts input data from switches and sensors, processes that data by making decisions in accordance with a stored program, ...

Safety is a major concern in a good many motor-driven applications. This is true in industrial applications where motion starts when power is applied and especially true when power is restored after ...