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

Final project – motor control program

To demonstrate all the concepts we have covered so far, let's build a motor control program. The program will simulate five motors. The motors will be in an array and the program will set the speed of the motors based on a persistent variable. To begin, let us create a motor structure:

TYPE motorStruct :
STRUCT
     motorStateMsg : STRING[20];
     motorState    : BOOL;
     motorSpeed    : INT;
END_STRUCT
END_TYPE

This code will create a structure that will dictate whether the motor is on with a Boolean variable, the motor speed (which will be set with an enum value), and a string that will tell which state the motor is in. After this structure is created, add an enum named motorSpeeds. Once you create the enum, add the code to match the snippet:

{attribute 'qualified_only'}
{attribute 'strict&apos...