Note: Updated For 2026

Books can teach you a lot about PLC programming, from ladder logic and structured text to working with specific platforms such as the Siemens S7-1200.

The collection below brings together the best PLC programming books. Some are free PDF downloads; others are sold as printed books or e-books.

I selected these books to help you choose from the many PLC programming titles available and spend your time and money on resources you can learn from.

You will find many types of PLC programming books online. Most cover PLC programming in general, including how a PLC works and how to use its programming languages. One common [...]

A PLC programming language I rate among the best visual languages is ladder logic, also called ladder diagram (LD).

Ladder logic is much more visual than most programming languages. That visual approach often makes the language easier for people to learn.

Ladder logic looks similar to electrical relay circuits. If you already have some experience with relay control and electrical circuits, that familiarity will likely help you learn it faster.

You don’t need that background to begin. When I first learned ladder logic, I didn’t understand relays either.

You can build and simulate ladder logic PLC programs for free. Follow this guide to download and install RSLogix Micro Starter Lite and RSLogix Emulate 500, then use them to test your PLC programs at no cost.

Ladder logic symbols are the building blocks of ladder diagrams. This guide covers the symbols defined in IEC 61131-3 and includes downloads in several formats, including a PDF you can keep for reference.

This is an introduction to PLC logic and how to use it to build PLC programs from simple electrical circuit diagrams. In this article, I will work with combinatorial logic to put together the functionality of a PLC program.

To bring the example closer to a real PLC programming language such as ladder logic, I will draw the PLC logic as contacts and relays in an electrical circuit.

Understanding a PLC begins with its basic architecture and the hardware inside it. The components are the physical building blocks that make up the PLC. Knowing what each of these parts does, and how it fits into the system, makes it easier to understand the PLC as a whole.

Having looked at what hardware is inside the PLC, we can now look at the software inside the PLC and how it runs.

Every PLC has a scan time and a scan cycle. Understanding these terms explains how the PLC works and how the software inside it runs.

During a scan cycle, the PLC gathers the inputs and runs your PLC program before updating the outputs.

The PLC needs some time to complete this process. That time is often measured in milliseconds (ms).

We call the amount of time the PLC needs to complete one full scan cycle the PLC’s scan time.

Let’s start with a few basic concepts that explain how a PLC program works.

Once you understand the PLC scan time, you can examine how the PLC program works. Combinatorial logic explains how logic combines true and false, its two states. Combining logic is also the basis of PLC programming. Since the two share the same fundamentals, combinatorial logic gives you a useful starting point for learning to program a PLC.