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

PLC code design

Since we are now moving into the PLC code development, we need to start looking at a design. Normally, the design of the PLC code is done in conjunction with the HMI design; however, we designed and implemented the HMI first because we are completing all the steps ourselves and this is an education project. Therefore, as stated before, it is common and best practice to perform the whole design phase for both the HMI and the PLC code at the same time if possible. Again, we only implemented the project the way we did so that we can have an HMI ready to start testing our PLC code.

To keep the design simple, let’s break the project down into the following function blocks:

  1. Oven: This function block will handle turning the oven on and off, as well as ramping the oven up to temperature.
  2. Alarms: This function block will trigger error, warning, and info alarms.
  3. Door: This function block will be responsible for locking and unlocking the oven door.
  4. ...