Programmable Logic Controller (PLC)

A Programmable Logic Controller (PLC) is an industrial-grade digital computer designed to perform control functions—especially for industrial applications. PLC is ubiquitous in process and manufacturing industries today. Initially built to replace electromechanical relay systems, the PLC offers a simpler solution for modifying the operation of a control system. Rather than having to rewire a large bank of relays, a quick download from a PC or programming device enables control logic changes in a matter of minutes or even seconds. The majority of PLCs today are modular, allowing the user to add an assortment of functionality including discrete control, analog control, PID control, position control, motor control, serial communication, and high-speed networking. Compared to older technologies, the PLC is easier to troubleshoot, more reliable, more cost-effective, and far more versatile.