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

Inheritance versus composition

Inheritance is a very important concept and is, without a doubt, a great way to recycle code under the right circumstances. However, many new or inexperienced programmers will often use inheritance as a means of importing code. This is a bad practice because instead of producing clean organized code, they produce jumbled-up code that has no true relationship between function blocks. When developing object-oriented code, it is very important to consider the relationships between function blocks. One very common way to implement object-oriented relationships is with a concept known as composition.

When to use composition

For many inexperienced, traditional programmers, composition is often an ill-understood but, ironically, often-used concept. Composition is where you include object references from one function block in another. In other words, composition allows us to assemble things. Whereas inheritance consists of an is a relationship between functions...