CODESYS ® is the leading manufacturer-independent IEC 61131-3 automation software for engineering control systems.


IEC 61131-3 Software Suite - the right decision for the Building Automation Industry

Buildings that already meet the standards of the future through the use of intelligent technologies sustainably save resources such as energy, natural gas, and water.

From the bare necessities to modern luxuries, energy in buildings is a must. In North America the major areas of energy consumption in buildings are:

  • 35% heating, ventilation, and air conditioning
  • 11% lighting
  • 18% major appliances such as water heating, refrigerators, and freezers, washing machines, dryer
  • 36% in miscellaneous areas including electronics.

With this in mind, energy efficiency in the construction of new buildings and in the renovation of existing buildings, complemented by low-carbon forms of new energy supply, are important aspects of today. Choosing the highly efficient building automation software CODESYS, investors, architects, planners, and technicians are able to generate a significant energy-saving potential of up to 30%, which directly affects the profitability of the investment.

All building technology systems are covered by CODESYS: from cooling, heating, ventilation, and air conditioning to lighting, shading, and energy data acquisition. The CODESYS IoT products ensure seamless and cycle-synchronous acquisition of building data. The cloud-based evaluation can be integrated directly into the control system.


  • CODESYS is a manufacturer-independent comprehensive and flexible system. All components for building automation applications are integrated directly in CODESYS, including editors for all IEC 61131-3 compliant implementation languages (6), compilers for native machine codes, a powerful debugger, and a clear project configuration. Add-ons can further supplement these components for efficient application development.
  • The Open Source Library ‘CODESYS Building Automation’ helps programmers to create building automation applications.
       - Room automation and controls such as lighting, blinds, access and security
       - Heating/cooling and ventilation (HVAC)
       - Control of aggregates for building automation
    In addition to numerous function blocks, the library also contains visualization elements for simulating and testing.
    Get started right away with the sample projects!
    The free of charge CODESYS Open Source Library is available in the CODESYS North America Store.
  • For efficient developments and diagnostics CODESYS has integrated analysis tests, simulations, and offline tests. 
  • CODESYS includes efficient configuration, commissioning, and debugging tools to assist building automation engineers throughout the development of their projects.
  • The option to use Object Oriented Programming (OOP) designs facilitates modular and highly reusable code for control applications and significantly reduce development and maintenance time. 
  • The CODESYS TargetVisu is ideally suited for the operation and maintenance of buildings directly on the controller.
  • CODESYS supports important communication protocols such as BACnet, OPC UA, MQTT, ETHERNET-IP or Modbus with integrated configuration tools. 


CODESYS Software Suite - perfectly suited for every industry

Application note
DALI-Aktoren via DALI-BACnet - Gateway MBS UGW

Application note
BACnet MS/TP via BACnet-MS/TP-Router MBS UBR-01 Mk II

Application Stories and Tutorials in BUILDING AUTOMATION

Part 1 - Introduction

Part 1 provides an overview of the solutions CODESYS offers for the most important challenges in the sector. After a comprehensive introduction, you will learn more about current standards, the levels of application development, and the benefits provided by CODESYS in Building Automation.

00:00  Intro
00:48  Overview
07:09  Standardization
11:57  Levels of application development
13:44  CODESYS features in Building Automation I
15:29  CODESYS features in Building Automation II

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CODESYS IN BUILDING AUTOMATION - Part 2 - standard features
Part 2 - CODESYS standard features for Building Automation

Part 2 begins with a brief introduction to CODESYS and its features. An example project will show you the concrete benefits of using CODESYS in Building Automation. We will introduce you to the most important features both in theory and in practice.

00:00 - Welcome
00:34 - Introduction to CODESYS
07:35 - Integrated visualization
09:41 - Libraries
10:52 - Project compare
11:39 - Revision control

Demonstration in CODESYS
12:31 - Contents of the example project
12:47 - Description of the project and its components
14:04 - Libraries
14:45 - Structured Text ST
15:49 - Visualization
16:14 - Projet compare and Revision control
17:24 - Live demonstration

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CODESYS IN BUILDING AUTOMATION - Part 3 - Important communication protocols
Part 3 - Important communication protocols

Part 3 will give you an insight into the most prominent communication standards in Building Automation. Protocols like BACnet, OPC UA, and KNX will be explained in theory and demonstrated practically.

00:00 - Welcome
00:51 - BACnet theory
04:12 - BACnet demonstration
08:40 - OPC UA theory
10:38 - OPC UA demonstration
13:21 - KNX theory
15:55 - KNX demonstration
18:44 - Modbus theory
20:32 - Modbus demonstration
24:38 - CANopen theory
27:02 - CANopen demonstration
32:22 - Network variables

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CODESYS IN BUILDING AUTOMATION - Part 4 - Application Composer
Part 4 - Application Composer

Part 4 will introduce you to the CODESYS Application Composer, which is a development tool for the efficient creation of application variants consisting of recurring functions. To get you started, we will explain the basic functional principle of the CODESYS Application Composer and its typical areas of implementation. This video will also use a sample project to demonstrate how to use the Application Composer, as well as a real world example.

00:00 - Welcome
00:22 - Introduction
03:20 - Creating modules
04:18 - Development of controller applications
05:34 - Demonstration in CODESYS
10:41 - Practical example

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In Part 5 you will learn more about the visualization integrated in CODESYS. Especially the HMI visualization is demonstrated with the help of an example project that you already know from previous videos of the series.

00:00 - Introduction
00:53 - CODESYS Visualization
02:36 - Demonstration in CODESYS

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Part 6 - More Features

In Part 6 you will learn more about the possibilities CODESYS offers in the areas of security, safety, and in the administration of your PLC landscape.

00:00 - Intro
00:56 - CODESYS Security
07:45 - CODESYS Safety
10:42 - CODESYS Automation Server

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CODESYS IN BUILDING AUTOMATION - Part 7 - for manufacturers of aggregates and plants
Part 7 - for manufacturers of aggregates and plants

Part 7 illustrates the challenges of the complex and rapidly developing industry that plant manufacturers face. With this in mind, you will learn how CODESYS can help you to create your own automation system quickly and safely.

00:00 - Intro
00:32 - Reasons to integrate freely programmable controllers
02:25 - Industry in transition - Soaring challenges for system integrators
06:05 - Industry in transition - Cloud software companies joining in
08:34 - Requirements for automation systems
10:47 - Realizing Building Automation systems with CODESYS
12:13 - Additional information

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CODESYS IN BUILDING AUTOMATION - Part 8 - for system integrators
Part 8 - for system integrators

Part 8 shows how system integrators can benefit by using CODESYS and freely programmable controllers. Selected example projects illustrate the benefits of working with CODESYS.

00:00 - Intro
00:27 - Reasons for the use of freely programmable controllers
04:02 - Advantages using CODESYS
07:02 - Projects realized with CODESYS

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