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

Auto declaring variables

In the previous chapters, we manually created variables. Manually creating variables is a common way of creating variables, but it is not the only way. CODESYS offers a simple tool for declaring variables called an Auto Declare tool. The tool is useful for declaring variables with data types that you may not be familiar with, creating a variable in a different file, and so on. The tool is also handy for assigning actual outputs, comments, and more for the variable.

The purpose of this tool is to help assist you in the creation of variables. However, this tool can easily be more trouble than it is worth. For the most part, it will be easier to declare a regular variable as we have been doing so far – that is, simply using the editor to write the variable’s code manually. However, if something is complex, in a different file, or you simply forgot the syntax, the tool can be of great value. In short, use the tool wisely and when necessary.

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