KNX Semantics and Smart Linking in ETS: Functions and Benefits

How semantics and smart linking are changing KNX project engineering

The project engineering of KNX systems is becoming increasingly complex. Modern building automation systems integrate a wide range of sensors, actuators and functions that need to be interconnected. In addition to established concepts such as group addresses, communication objects and function blocks, new approaches within the KNX standard are gaining importance.

These include semantic data and smart linking. Although these concepts have existed for several years, they are only now becoming practically relevant due to the growing implementation of semantic data in KNX devices. Alongside topics such as security and encryption within the KNX standard, the structured description of data points is also becoming increasingly important.

These technologies are designed to support system integrators in structuring and engineering KNX systems more efficiently. Particularly in larger projects, a clearer description of data points and functions helps to identify relationships within the system more quickly and simplifies typical workflows in ETS.

In this article, you will learn what KNX semantics and smart linking are, how they relate to each other, and what practical benefits they offer for project engineering in ETS.

Smart Linking in the KNX ETS with channel selection and assignment of functions to group addresses based on semantic data

Structured links in KNX project planning using semantics and smart linking

Devices describe their function

Semantics in the KNX standard

In the KNX standard, semantics means that data points and communication objects are not only defined technically, but also in terms of their function within the system. A data point no longer represents just a technical value, but gains a contextual meaning, for example as a temperature value, wind alarm or brightness signal.

This semantic information is defined by the device manufacturer within the KNX application and is available in ETS as well as in supporting tools such as the KNX Association’s Smart Linking App. This enables software tools to better understand how functions are related across the channels of KNX devices and what role individual data points play within the system.

The quality and completeness of this semantic information depend directly on how it is implemented within the respective device application by the manufacturer.

As a result, a data point is no longer interpreted purely as a technical value, but can also be differentiated in context. For example, it becomes possible to distinguish whether a temperature value refers to an indoor or outdoor measurement.

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Identify connections more quickly

Smart Linking in ETS

Based on semantic information, the KNX Association’s Smart Linking App can identify potential connections between channels of KNX devices and provide system integrators with suggestions for appropriate links between communication objects. Typical functional relationships can therefore be identified more quickly. For example, weather data from a KNX weather station can be linked to shading or ventilation functions.

These connections are not created automatically. Instead, integrators receive structured suggestions that they can review, apply and adapt as required. These suggestions are based, among other factors, on the functions and properties of the devices used.

Compared to traditional project engineering, this means that relationships no longer need to be identified and assigned entirely manually. Instead, they become visible more quickly through semantic information. Particularly in larger projects with many functions, this approach can help to:

reduce engineering time
avoid errors when assigning communication objects
improve the structure of ETS projects

Smart linking does not replace project engineering in ETS, but provides targeted support and increases efficiency.

Foundation for automated functions

Practical example: weather data in a KNX system

Weather data plays a central role in many KNX installations, as it can influence multiple building functions at the same time.

KNX weather stations typically provide data such as:

wind speed
brightness
temperature
precipitation

This information is commonly used for functions such as shading, ventilation or energy optimisation.

In a traditional KNX workflow, these relationships had to be identified and implemented manually. Integrators needed to determine which data points were relevant and how they should be linked to other system functions via communication objects.

With semantic data, these relationships can now be described in a structured way. Software tools are able to recognise which functions are based on the same data and are logically connected. For example, the Smart Linking App can identify that a wind alarm is related to a shading function and suggest appropriate links.

As a result, a data point is no longer interpreted purely as a technical value, but can also be differentiated in context. For example, it becomes possible to distinguish whether a temperature value refers to an indoor or outdoor measurement.

Conclusion

Semantics and smart linking: the future of KNX project engineering

With semantic data and smart linking, KNX project engineering is evolving towards more structured and intelligent workflows. KNX devices can describe their functions more clearly, while software tools can better identify relationships between sensors, actuators and automation functions.

For system integrators, this primarily means less manual assignment of communication objects and a clearer overview of complex projects. Semantics does not replace traditional engineering in ETS; rather, it enhancesit with additional information that makes functional relationships visible and supports configuration more effectively.

Especially in larger installations involving multiple building systems, this approach helps to structure systems more efficiently and simplifies typical planning and parameterisation tasks. For this reason, system integrators benefit from familiarising themselves with these developments in the KNX standard at an early stage.

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FAQ

Frequently asked questions about semantics and smart linking

Does smart linking work with every KNX system?
Smart linking only works with devices that support semantic data. In existing KNX projects, limitations may therefore occur depending on the hardware and applications used. The more devices provide semantic descriptions, the greater the benefit.

What are the requirements for semantics and smart linking?
The prerequisite is that KNX devices provide semantic information within their application. This data is defined by the manufacturer and must be supported by ETS and tools such as the Smart Linking App.

Can smart linking be integrated into existing KNX projects?
In principle, yes – provided compatible devices and up-to-date ETS versions are used. The actual benefit in existing projects depends on whether the installed devices already support semantic data or are extended with new devices.

Do I need to change the way I work in ETS completely?
No. Traditional project engineering remains unchanged. Smart linking complements existing workflows by providing suggestions for connections and making relationships more transparent.

Are semantics and smart linking already implemented by manufacturers?
Yes. Some manufacturers already integrate semantic data into their KNX devices to support project engineering in ETS. Elsner KNX weather sensors, for example, include semantic extensions to better represent relationships between data points and system functions.

Are there training courses or support available for smart linking?
As semantics and smart linking are still relatively new developments within the KNX standard, relevant content is increasingly being integrated into training and further education programmes.