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Mastering PLC Programming

You're reading from   Mastering PLC Programming The software engineering survival guide to automation programming

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Product type Paperback
Published in Mar 2023
Publisher Packt
ISBN-13 9781804612880
Length 386 pages
Edition 1st Edition
Tools
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Author (1):
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M. T. White M. T. White
Author Profile Icon M. T. White
M. T. White
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Toc

Table of Contents (25) Chapters Close

Preface 1. Part 1 – An Introduction to Advanced PLC Programming
2. Chapter 1: Software Engineering for PLCs FREE CHAPTER 3. Chapter 2: Advanced Structured Text — Programming a PLC in Easy-to-Read English 4. Chapter 3: Debugging — Making Your Code Work 5. Chapter 4: Complex Variable Declaration — Using Variables to Their Fullest 6. Part 2 – Modularity and Objects
7. Chapter 5: Functions — Making Code Modular and Maintainable 8. Chapter 6: Object-Oriented Programming — Reducing, Reusing, and Recycling Code 9. Chapter 7: OOP — The Power of Objects 10. Part 3 – Software Engineering for PLCs
11. Chapter 8: Libraries — Write Once, Use Anywhere 12. Chapter 9: The SDLC — Navigating the SDLC to Create Great Code 13. Chapter 10: Advanced Coding — Using SOLID to Make Solid Code 14. Part 4 – HMIs and Alarms
15. Chapter 11: HMIs — UIs for PLCs 16. Chapter 12: Industrial Controls — User Inputs and Outputs 17. Chapter 13: Layouts — Making HMIs User-Friendly 18. Chapter 14: Alarms — Avoiding Catastrophic Issues with Alarms 19. Part 5 – Final Project and Thoughts
20. Chapter 15: Putting It All Together — The Final Project 21. Chapter 16: Distributed Control Systems, PLCs, and Networking 22. Assessments 23. Index 24. Other Books You May Enjoy

Getting to know methods

The term method has been thrown around a few times thus far in the book. A method is a special type of function that belongs to a function block. Methods are members of function blocks that consist of blocks of code that are executed when called. Without methods, a function block is mostly useless. To conceptualize a method, consider the blueprint example before. If the function block is a car, then the methods are the brakes and engine of said car.

Unlike the functions we explored in Chapter 5, methods are not global. This means that they cannot be called from anywhere like the functions we previously explored. Essentially, the only place that can call these functions is a file with an object to the function block or from somewhere inside the function block, such as another method.

To create a method, you must first have a function block. Since we already have a Calculator function block, we are going to add four methods to it that will handle addition...

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