Book Image

Mastering PLC Programming

By : Mason White
Book Image

Mastering PLC Programming

By: Mason White

Overview of this book

Object-oriented programming (OOP) is a new feature of PLC programming that has taken the automation world by storm. This book provides you with the necessary skills to succeed in the modern automation programming environment. The book is designed in a way to take you through advanced topics such as OOP design, SOLID programming, the software development lifecycle (SDLC), library design, HMI development, general software engineering practices, and more. To hone your programming skills, each chapter has a simulated real-world project that’ll enable you to apply the skills you’ve learned. In all, this book not only covers complex PLC programming topics, but it also removes the financial barrier that comes with most books as all examples utilize free software. This means that to follow along, you DO NOT need to purchase any PLC hardware or software. By the end of this PLC book, you will have what it takes to create long-lasting codebases for any modern automation project.
Table of Contents (25 chapters)
1
Part 1 – An Introduction to Advanced PLC Programming
6
Part 2 – Modularity and Objects
10
Part 3 – Software Engineering for PLCs
14
Part 4 – HMIs and Alarms
19
Part 5 – Final Project and Thoughts

Exploring functions

The most fundamental module of any program in any programming language is the function. We’ve thrown around the term quite a bit, but what is a function? In the most basic sense, a function is a named, callable block of code that performs a task. Essentially, a well-written program will be a collection of functions.

With that being said, it is common for entry-level students and non-formally trained professionals to assume that a function is merely allocating functionality to separate files. This, however, is a major fallacy that can lead to a poorly written program that will not last. Though it is very common to split functions into separate files in PLC programming, a separate file is not a function. As such, it is important to remember that there is a major difference between code in separate files and functions.

What goes into a function?

Before we start writing functions, we need to determine what goes into a function and when a function needs...