Introduction to PLC programming with OpenPLC, the first fully open source Programmable Logic Controller on the Raspberry Pi, and Modbus examples with Arduino Uno and ESP8266.

PLC programming is very common in industry and home automation. This book describes how the Raspberry Pi 4 can be used as a Programmable Logic Controller. Before diving into programming, the author starts with the software installation on the Raspberry Pi and the PLC editor on the PC, followed by a description of the hardware.

You'll find interesting examples in different programming languages complying with the IEC 61131-3 standard. This manual also explains in detail how to use the PLC editor and how to load and execute the programs on the Raspberry Pi. All IEC languages are explained with examples, starting with LD (Ladder Diagram) to ST (Structured Control Language) and SFC (Special Function Chart). All examples can be downloaded from the author's website.

Networking is given thorough attention as well. The Arduino Uno and the ESP8266 are programmed as Modbus RTU or Modbus TCP modules to access external peripherals, read sensors, and switch electrical loads. I/O circuits complying with the 24 V industry standard may also be of interest to the reader.

The book concludes with an overview of commands for ST and LD. After reading the book, the reader will be able to create their own controllers with the Raspberry Pi.