PLCs
A PLC, or programmable logic controller, is a rugged industrial computer that reads sensors and runs motors, valves, and other devices according to its program. Nearly every manufacturer, water utility, food plant, and packaging operation depends on PLCs. When buying, think about input and output count, communication protocols, safety rated options, and whether your maintenance team already knows that platform. Many plants finance a migration from obsolete controllers to a current platform before a failure forces the issue. Used PLC hardware is common for spares, but new is the norm for full upgrades.