Open Systems for Homes and Buildings: Comparing LonWorks and KNX
This white paper examines the development of the ideas and the impact of design and marketing decisions during that development, the associations that support the respective technologies and their impact in one particular market: home and building electronic systems.

Those two technologies are LonWorks from the Echelon Corporation and European Installation Bus (EIB) – now the mainstay of Konnex (KNX) – originally developed by Siemens. The scope of the study is limited to the application area of the latter technology: LonWorks is used in a much wider range of applications.

Executive Summary

It has been over ten years since Alan Kell first compared a number of bus systems for building control and, whilst a number of differing bus systems were considered, it was apparent then that two, European Installation Bus (EIB) and LonWorks, were the leading contenders. Among the others considered, European Home Systems and BatiBUS have merged, with EIB, in the KNX protocol whilst some, CEbus and SmartHouse from the US, never really made any substantial progress and, in the case of the latter, managed to achieve insolvency three times.

In the succeeding years both EIB and LonWorks have made substantial progress and a number of the issues noted in the earlier report have been addressed. LonWorks has acquired a two-wire, free-topology medium that was under development at the time of that first report, EIB has acquired a powerline medium and the installation tools have come on in leaps and bounds.

Both protocols have also adapted, to varying extents, to the most significant change in homes and buildings; the growth of information networks in general, the development of additional Internet protocols and, most importantly, the use of the Internet itself and the new terminology that this involves: web servers, web services, HTML, XML, etc..

There are differences. LonWorks has, as might be expected given its general nature, been adopted for a number of applications well outside the home and building space whilst, within that space, it is used for a wide variety of applications: lighting, heating, air conditioning, security, lift control, fire alarms and related devices and access control. The technology provides sufficient flexibility and capability that many complex buildings use LonWorks as the only control system. It is also apparent, both from product catalogues and from membership of the LonMark Interoperability Association (now LonMark International), that the applications are substantially worldwide. Europe plays a significant role in this global demand and Germany is host to the largest and most active of all the LonUser groups - the LON Nutzer Organisation or LNO as it is known.

EIB's use is more limited with the majority of applications being in the lighting, heating and shading space. The bulk of the products originate from German manufacturers and are used within Germany and its close geographical neighbours. However, within that area, there is a high degree of penetration within the commercial building sector, less so in the residential sector, and this is due, in large part, to the successful inclusion of EIB technology in the education and training programmes for professional electrical installers.

Overall we believe that the EIB technology is well adjusted to the electrical installation industry in Germany and surrounding countries and to the smaller building arena. We hear some reservations as to the ease with which it can handle larger buildings although we note many successful large projects. However these appear to also require other technologies, such as BACnet, to be included for security and HVAC applications. EIB appears to rely heavily on BACnet, and BACnet tool vendors, to provide support for larger installations and to handle enterprise-wide integration.

EIB training appears to be very well integrated with the training of installers and planners in Germany - less well so elsewhere - and has led to a wide understanding of the technology.

We believe that products incorporating LonWorks technology are suitable for both these larger buildings and for small buildings enabling the use of a single technology for all control applications in both commercial buildings and in homes. In the latter, good powerline technology coupled with self-installation methods fit well with the electrical installer. in business the technology is aided by the powerful LonWorks Network Operating System (LNS) and by the PanoramixTM Platform which permits enterprise-wide data integration at a machine to machine level. Hence the accounts department can, for example, track worldwide energy expenditure on a minute-by-minute basis. The very powerful installation tools, and their associated cost base, may require revision for smaller installations if they are to be seen as cost-effective.

LonWorks training has been delivered to a substantially smaller number of people concentrating on the more professional installers and integrators of larger systems. The similarity of EIB and LonWorks technologies should enable conversion training where required.

Obtain the full document in English or German by visiting i&i limited at http://www.iandi.ltd.uk.

About i&i limited

Alan Kell was the principal author of the 1993 study by DEGW etl entitled "Bus Systems for Building Control" which was the first detailed study in this area to compare, among others, EIB and LonWorks in the context of building control.

Peter Colebrook collaborated closely with Siemens in Regensburg in the late 1980's, was one of the 12 founder signatories of the European Installation Bus Association (EIBA) and subsequently served as a Director of that Association. He was also one of the founders of the LonMark Interoperability Association and similarly served as a Director of that Association.

Alan and Peter are directors of i&i limited. The Proplan division of i&i, established in 1980, has analysed the markets and technology for building controls and services in 37 different countries in North America, Western and Eastern Europe, Scandinavia, the Middle East, S.E. Asia and the Far East including Japan and China. A series of Multi-client studies entitled "Intelligent Controls in Buildings" have charted the progress of the advanced building controls industry and its players for seventeen years.

The objective has been to provide manufacturers and suppliers with accurate information on which to develop appropriate marketing and business strategies. This has been achieved with the assistance and co-operation of our clients who comprise the major suppliers to this business, including; ABB Building Technologies, Automated Logic, Novar Trend, Novar Gent, Carrier, Danfoss, Groupe Schneider, Honeywell Controls, Invensys, IBM, Johnson Controls, KMC, Olivetti, Omron, Philips, Saia, Satchwell Control Systems, Sauter, Siemens Building Technologies - Cerberus Division, Siemens Building Technologies - Landis & Staefa, TAC AB, Trane, Tyco, Weidmueller, Zumtobel.