A programming language for PLCs. It represents logic in a form resembling an electrical schematic of relay circuits (which kind of looks like a ladder with rungs and rails). Each rung defines a logical operation: contacts (inputs) on the left that simulate relay contacts, and coils (outputs) on the right. Ladder logic is popular because it’s very intuitive for engineers with electrical backgrounds. It’s part of the IEC 61131-3 standard languages for PLCs (along with others like Functional Block Diagram, Structured Text).
