This document provides information about programmable logic controllers (PLCs), including:
- PLCs were developed in the 1960s to replace relay control systems and reduce costs for automakers. They allow flexible control without rewiring.
- PLCs have a CPU that runs a user program to monitor inputs and control outputs based on logic. Ladder logic is a common programming method that resembles electrical diagrams.
- The document discusses PLC components, architecture, programming methods like ladder logic, common instructions, timers, counters and their applications in automation. It also provides an introduction to supervisory control and data acquisition (SCADA) systems.