OpenPLC — The Complete Guide: Open-Source PLC Programming to IEC 61131-3

OpenPLC is an open automation platform from Autonomy Logic for programming controllers to IEC 61131-3. You write logic in the editor, test it in the simulator and deploy it to a runtime that runs on a computer or a small controller.

OpenPLC

Autonomy Logic

Open IEC 61131-3 PLC editor and runtime — ladder, FBD and ST, with a built-in simulator and deployment to Raspberry Pi and Arduino.

Get it from the vendor

What you get

Three programming languages — Ladder Diagram, FBD and Structured Text.
Built-in simulator — run the logic with a live debugger, no hardware needed.
A flexible runtime — Linux, Windows, macOS and Docker.
Low-cost hardware — Raspberry Pi and small microcontrollers, including Arduino.
Learning and prototyping — an inexpensive way to learn PLC programming and build small control systems.

What is free and what is paid

The Community Edition is open and free for any use: the editor and compiler are under GPL-3.0 with a runtime library exception, and the runtime is under MIT. Paid: the Autonomy Edition for production deployments (with IEC 62443 security, proprietary protocols and support), the Autonomy Edge cloud services and commercial support. For learning, prototyping and small projects the free edition is enough.

Related tools

To test Modbus communication with the controller — QModMaster. To program microcontrollers directly — Arduino IDE. For a graphical measurement and control environment — LabVIEW Community.