Industrial Control Systems Basics

Industrial Control Systems (ICS) are the computers and devices that monitor and operate physical processes: power grids, water treatment, manufacturing lines, pipelines, and building systems. Together with the broader category of Operational Technology (OT), they bridge the digital and physical worlds.

A failure here is not lost data; it can mean stopped production, environmental harm, or risk to human life.

A Programmable Logic Controller (PLC) is a ruggedized industrial computer that reads sensor inputs and drives actuator outputs in real time. It executes control logic in a continuous scan cycle: read inputs, run the program, write outputs, repeat.

• Deterministic and reliable, built for harsh environments
• Often programmed in ladder logic resembling relay diagrams
• Directly controls valves, motors, pumps, and breakers