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

Product type Paperback

Published in Mar 2023

Publisher Packt

ISBN-13 9781804612880

Length 386 pages

Edition 1st Edition

Languages

PLC programming

Tools

PLC

Concepts

PLC Programming

Author (1):

M. T. White

View More author details

Table of Contents (25) Chapters

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

Why subscribe?

24. Other Books You May Enjoy

Understanding state machines

As a software engineer, especially one that writes PLC code, you must understand what state machines are. State machines to PLC programmers are what the Model-View-Controller (MVC) pattern is for web developers. To be a quality PLC programmer, you must understand what a state machine is and how to implement one.

The most simplified way to think of a state machine is as a series of states that can transition from one state to another. A simple example of a state machine is a lightbulb connected to a switch. The following diagram represents the state of a lightbulb:

Figure 2.14 – Lightbulb state machine

As can be seen with the arrows, if the lightbulb is on, it can transition to off when the switch is flicked down. If the lightbulb is off, it can transition to an on state when the switch is flicked up.

The majority of state machines that you are going to work with as a PLC programmer are called finite state machines...