Articles and whitepapers

Update on KNX - Why it Makes Sense (3/8/2007)

By Colin Price, Ivory Egg (UK)

KNX, or 'the protocol formally known as EIB (European Installation Bus)', is dominant in Europe and rapidly gaining traction as a building control system in the UK. This article will summarise where KNX has come from, and what it is about. We will discuss how developers' and home buyers' expectations have changed over recent years, and why it is important for smart home systems to be based on open protocols such as KNX.

Indeed, how can it be that KNX is so well-known in Europe and yet has not been adopted here in the UK, and why is now the right time, as in installer or user, to get to know KNX?

What is KNX?

Founded in the late eighties by a number of major European manufacturers such as ABB, Gira, Jung, Merten, and Siemens, the KNX Association (then the EIBA) now guides and defines the strategy of KNX for the future. Historically known as Instabus or EIB, KNX quickly became well-established in Europe. Being totally scalable, it is suited to installations from flats to airports, and at the last count, is estimated to be installed as a base level building control system in more than 40% of all new-build commercial space in Germany.

Gira KNX-compatible control plate, for controlling heating, lighting and AV.

After Germany, the largest markets are Holland, Spain, Belgium and Scandinavia. UK has lagged behind, but is catching up fast with the largest commercial projects, such as Heathrow Terminal-5, and many residential developments incorporating some or all of the functionality.

With around 140 companies already manufacturing KNX equipment, three of which are based in the UK, the future of KNX as a dominant technology is assured.

In 2003, KNX defined itself as the only international standard platform for building control when it was accepted as a European standard, EN50090, and now as an international standard ISO/IEC14543. These marks of approval provide a solid platform from which the member manufacturers use the protocol to deliver a vast array of totally interoperable products.

Key facts about KNX

1. KNX is a two-wire field-bus system with distributed intelligence, i.e. there is no central processor.

2. Sensors (switches) come in many functional and style variants, and task specific actuators are normally DIN rail mounted centrally.

3. Interfaces exist with most other systems including IP, DALI, DMX, RS232, Crestron, and AMX.

4. KNX is designed, configured, commissioned and maintained using a single software tool called ETS. This manufacturer-independent software is used to bring together products from multiple vendors in a design project using a simple drag-and-drop interface.

5. Qualification to become an accredited 'KNX Partner' can be obtained at one of three UK training schools.

ETS software with drag and drop interface for designing, configuring, commissioning and maintaining KNX-based systems.

For information about the protocol and installation, see hiddenwires.co.uk/resourcesarticles2006/articles20060103-04.html

Changing expectations

It can be argued that in the 1990s, lighting control was all that anyone associated with a residential control system. Now in the 'thoughtful noughties' the expectation is for lighting and heating control, as well as other functions, to be integrated together and driven from a single, simple front end. KNX delivers this by integrating heating, cooling, lighting and interfacing with systems such as AMX or Crestron simply and seamlessly. So, from being seen as a 'one-of-many' type product for lighting control, KNX stands apart from the rest as a holistic control system.

Additionally, and crucially, customers will no longer compromise style for functionality in their homes. Not only must the front-end - the 'bits on the wall' - look fantastic, be totally joined-up and simple to use, but the technology has to work reliably every single time it is called upon. KNX delivers this by having a wide choice of switch styles from a variety of manufacturers that include lighting, door entry, thermostats, data sockets and all the electrical accessories to finish a property consistently and beautifully.

ABB smart touchpanel.

Gira Homeserver3 user interface working on a PDA.

Why does the UK lag behind?

Until now, KNX has not been embraced in the UK in the same way as continental Europe. In no particular order, below are some of the arguments that have been levelled at KNX and, as I see it, the response of the industry to them:

1. A majority of the manufacturers are German, and the feeling is that they concentrated on their home markets first and left the English-speaking markets for later. As a result there has been limited information available in English, and we live on an island and need people to sell to us and support their products in English. The manufacturers have responded, and these days all programs and documentation are quickly available in English, making language much less of an issue.

2. KNX has suffered from not knowing what to call itself, and so the market hasn't known what to call it either - EIB, Instabus, EcoBus, iBus, Konnex, KNX are all names for the same thing. Since earlier this year, the name KNX has been fixed in stone, so finally we know where we are.

The KNX logo.

3. It could be argued that as an open standard no-one has been flying the flag for KNX in the UK. Understandably the manufacturers can only really promote their own brands, but with exposure of KNX at events like CEDIA Expo and the T3 Smart Home Show, and the formation of the KNX UK Association, there is a much greater visibility of KNX in the market and a greater understanding of KNX as a truly open system.

4. Historically, KNX products only fit into European backboxes. Problem? Not really. The European round boxes are easy and cheap to fit, or alternatively, Siemens have developed a range of sensors that fit UK square boxes, or adapter plates can be bought to fit UK boxes.

Recent developments and the future

KNX recognises the importance of IP, and in the last few years, KNX products have evolved with this movement so that many flavours of screen, interface and gateway are available. KNX can be controlled, programmed and diagnosed remotely by both the customer and integrator over IP, either via the Internet or over the LAN. Devices are available that deliver complex visualisation and functional interfaces.

To be a truly-integrated building control system, AV control must also be seamless, so, companies such as DKT and B+B technologies have developed AV interfaces that integrate with almost any of the major systems, thus allowing two-way communication of AV control from KNX, and control of the KNX from the likes of Crestron. So, KNX might be used to control multiroom audio whilst at the same time Crestron tablets are being used to display and control the heating.

Conclusion

KNX is a huge force in the European building controls market, and the UK is catching up fast. I would encourage all new integrators and installers to have a look at KNX to see if it is right for them. For the user and installer, KNX is a 'Mercedes' type product where you get the quality and reliability that is required and expected. It is a professional install which protects the installer's initial investment in becoming skilled, and the protocol continues to evolve, so it is here to stay. If you are in this market either as a user or an installer then at the very least KNX bears a good long look - I think you'll be delighted with the aesthetic possibilities and amazed by what it can do.

Useful KNX resources:
www.eibshop.co.uk - UK-based supply of parts, information and support.
www.knx.org - EU governing association of the protocol.
www.knxuk.org - UK trade organisation.
www.eibhome.com - useful site.
www.light-building.messefrankfurt.com - trade fair that features KNX.

Colin Price is a Director of Ivory Egg (UK) Limited, specialist wholesaler of a full range of KNX and related products, and provider of expertise and technical support.

www.ivoryegg.co.uk