Some PLCs are very simple and some are quite complex, but one thing they do have in common is they are usually programmed using ladder logic. If you’ve ever wanted to learn how to program PLCs ...

They are programmable via software interfaced via standard computer interfaces and proprietary languages ... Relay Ladder Logic (RLL), or ladder diagrams, is the primary programming language for ...

A family of programming languages for programmable logic controllers (PLCs). Of the three graphical and two textual languages, ladder logic (see example below) was the first language and widely used.