My Smart Home speaks KNX

Put simply, KNX is the language that light switches, motion detectors, brightness sensors and all the other components of a smart home system use to communicate with one another.

6:10 a.m.

– The alarm goes off, just like it does every day. I stay in bed for 20 minutes, checking my emails and notifications on my tablet while the heating in the bathroom and kitchen gets activated.

6:30 a.m.

– The bathroom is warm. As I enter the room, the light goes on. I step into the shower to wash away the last bits of tiredness. When I turn off the water, the coffee machine in the kitchen switches on.

6:50 a.m.

– The coffee pot is filling up. Dried off and dressed, I arrive in the kitchen right in time for a freshly brewed cup of coffee. As the sun rises outside, the blinds go up automatically.

From a non-profit idea to modern building control

As complex technical systems, modern buildings are home to a multitude of control units. To connect these in an intelligent and efficient way, data should be transmitted via a common path, independent of the transmitter and receiver. “Bus systems” establish these kinds of connections between technical equipment in an automation system – using standardised protocols to define identifiers, measurement data or commands – and enable a unified exchange of information between all components.

In 1990, the KNX Association developed the KNX bus, the only open standard for home and building systems technology globally. The founding members of this non-profit organisation include renowned companies such as Siemens, Merten, Hager and, last but not least, Gira. To date, more than 370 companies have joined the organisation. The advantages compared to conventional electric installations are obvious.

Intelligent control in your own home

New elegance on the wall - The Gira G1. Source: Gira

A separate control unit for information exchange

In conventional systems, control functions are usually connected to energy distributors. This goes hand in hand with a great deal of wiring, planning, and installation work - not to mention the high costs. Even implementing simple higher-level functions – such as centrally switching several circuits on and off, or making subsequent switching changes – is a laborious process. However, forming a separate control network, KNX bus lines enable the cross-system exchange of information between sensors – such as the presence detector in my bathroom – and actuators, such as the light switch in this case. The wires needed to connect the devices can either be laid individually or parallel to the building’s power supply. Alternative variants are based on Ethernet or wireless transmission.

KNX: individualised programming and control

With the support of the KNX protocol, manufacturers can ensure that their smart home products can be easily combined and controlled in a unified manner within one system..

The heating actuator that “speaks” KNX pre-heats the bathroom for 20 minutes after my alarm goes off. The room lighting responds to KNX presence detectors and brightness sensors. The coffee machine is programmed to switch on as soon as the water is turned off using the KNX shower valve. Ultimately, almost all functionalities can be connected and adjusted to suit individual needs and energy efficiency requirements. Desired actions are defined during the system programming process (“parametrisation” is the specialist term for this) and can be changed at any time.

As a standardised, independent, flexible and compatible system solution, the KNX enables all control processes in the building to be centrally recorded and displayed. Gira offers an extensive range of compatible components.

And what happens during the weekend? I set my alarm at 9 a.m. and let the blinds, lighting, heating and, of course, the coffee machine sleep in too.


What do you think of the KNX building control technology? We look forward to receiving your comments.

Building technology KNX System Smart Home

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