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Using the CODESYS Help

The CODESYS Help is intended to assist you in using the CODESYS Development System easily and successfully. You will find quick answers to questions and solutions to problems.

Each help component consists of a concept section and a reference section.

In the concept sections, we explain in detail all of the topics which are relevant to create a CODESYS project. The concepts are supplemented with instructions which guide you step-by-step to the desired result.

In the reference sections, we provide complete reference works for the user interface and programming of CODESYS.

In the CODESYS options, you determine whether to use the CODESYS Offline Help or the CODESYS Online Help.

You can call the context-sensitive help directly from the user interface of the CODESYS Development System. In CODESYS, when you hover the cursor over an object, menu command, or programming element, and then press the F1 key, the respective help page opens. Alternatively, you could also use the commands in the Help menu. This is a full-text search. The index search is possible only in CODESYS Offline Help.

Search operators for the offline help

  • AND

    Used automatically, for example the input of the search terms Device Diagnosis has the same results as the input of Device AND Diagnosis

  • The * placeholder is used automatically. However, the * character must not be used as a wildcard because in this case the * character will be searched for specifically.

CODESYS system overview

The CODESYS Development System IEC 61131-3 programming tool forms the core of the CODESYS software platform for tasks in industrial automation technology. With additional, integrated solutions for motion control, visualizations, and fieldbus connections, the usual practical requirements are covered in one system.



The free CODESYS Development System is an IEC 61131-3 programming platform for automation devices controller tasks. It provides diverse and convenient engineering functions to help you with your developing tasks:

For this, see the online help topic:

Using wizards for project configuration

Creating and Configuring a Project

Customizing the user interface

Customizing the User Interface

Generating professional controller applications according to IEC 61131-3 with many standard functions

Programming of Applications

Convenient programming using the mouse and keyboard in all languages of IEC 61131-3

Corresponding editors for FBD, LD, IL, ST, SFC, including the variants CFC and extended CFC

Programming Languages and Editors

Input assistance for entering and configuring different data

Using Input Assistance

Support for object-oriented programming

Authentic object-oriented programming according to IEC 61131-3 3rd Edition in all languages of the IEC 61131-3 possible without additional tools

Inheritance of POUs to similar application parts in order to reduce development time and errors

Object-oriented programming is no mandatory: Functional or object-oriented programming can be employed and combined as you like.

Object-Oriented Programming

Comprehensive project comparison, even for graphical editors

Comparing Projects

Library concept for simple reuse of application code

Using Libraries

Debugging and online properties to optimize the application code and to speed up testing and commissioning

Testing and Debugging

Integrated compiler for many CPU platforms to optimize the performance of the controller

Compiler version

Compile Options

Security properties to safeguard the source code and operation of the controller

Protecting and Saving Projects

Protecting an Application

Handling of Device User Management

Managing Packages and Licenses

Fieldbus support and programming of devices from different manufacturers

Configuring I/O Links

Extensibility and adaptability without leaving the product interface

Managing Packages and Licenses

In addition:

Seamlessly integrated tools for other automation tasks, for example CODESYS Visualization, CODESYS SoftMotion, and CODESYS Application Composer

At any time, you can extend the functionalities by means of add-on Packages which are provided in the CODESYS Store International.

Setting the language of the user interface

In the Options → International Settings dialog, you can set the language which the user interface of the development system displays at the next start. You can specify the language of the help separately.

If you start CODESYS from the command line, then you can add a parameter to specify the language of the user interface.

Copyrights and trademarks

The rights of all companies and company named cited in this CODESYS Help, as well as products and product names, are reserved by the respective companies. Technical specifications are subject to change. Reproduction or further use of this help or parts of it require the express prior authorization of CODESYS GmbH.