PLCs Chapter 2 Lecture 3 - CPU, Memory and HMI's

In this lecture, we will turn our attention to the core components that bring a PLC system to life. We’ll begin with the Central Processing Unit, often referred to as the brain of the PLC, which executes the control program and makes the decisions that drive the system. From there, we’ll look at PLC memory, where programs and process data are stored and retrieved during operation. Finally, we will explore Human-Machine Interfaces (HMIs), which serve as the link between operators and the automated system, replacing traditional control panels with graphical, touchscreen displays. Together, these topics provide a deeper understanding of how PLCs think, remember, and communicate—both with people and with machines.