星空传媒

Business trips are a real hassle: strange airport, strange town and worst of all, strange rental car. You know the drill; nothing is where it is on your own car. The indicator stalk is the other side of the steering wheel so you are forever flashing your headlights instead of indicating a turn. The petrol cap is on the wrong side which is a real pain and the radio has a mind of its own; serving only rap music if your preference is classical and vice versa. You would have thought manufacturers could have worked out some sort of standard by now.

Some business sectors have managed to get further than the car industry. The IT world has the de-facto Wintel (Windows plus Intel) standard in which (assuming you don't have an Apple, Unix or Linux computer) you can swap files between different systems without a problem. This standard came about by pure commercial pressure. Whether or not you agree that a few companies should impose their technology on an industry, there are plenty of examples, which show it to be vital to industry and market expansion. VCRs, electricity supply, telephones and railways are examples of innovations, which did not really begin to expand until one technical standard rose to dominance.

Most markets follow the same general path. Initially, the market is fragmented as suppliers see the opportunities in different ways. Engineers design products independently according to their own experience and prejudice. As the market grows and customers require products from different companies to inter-operate, many ad hoc schemes to link and integrate these systems are developed. Through a process of economic natural selection and customer pressure, the number of technologies is whittled down to a few. A dominant standard is imposed often by the largest supplying company in the market (as Microsoft has done in pcs) or by a powerful buyer (such as the US Department of Defense did with transmission control protocol/internet protocol (TCP/IP). It is not obvious at the outset, which will be triumphant but invariably one is.

Leading the field
From a technical point of view the intelligent building market can be seen as having passed the initial stage and is now consolidating. In the last five years the list of contenders for the standard building control protocol has been whittled down until it seemed there were only two protocols with a chance: BACnet and LonWorks. Until recently, the proponents of each seemed to spend as much time attacking the other as promoting themselves. Now peace has broken out largely thanks to some new kids on the block: Niagara and eXtensible Markup Language (XML). At the recent BuilConn convention in Dallas it became apparent that there may be a place for all of these technologies. If one of them finally does become predominant then the process will be gradual but will not hinder the larger movement: the realisation of the intelligent building.

So are these protocols competitive or complementary? Well confusingly, a bit of both. BuilConn confirmed that each has a role to play and because each is developing quickly, choice, economy and span of control is increasing rapidly for owners, operators and occupants.

LonWorks, invented, developed and promoted by the Echelon corporation can be viewed as building automation for plumbers; the output of one device is fed into the input of another using a common data pipe. This is often the LonBus but it can be a power cable, wireless or a number of others. So controls bought from one company can be hooked up to the machinery from another fairly easily. LonWorks does not depend on a central computer but it does require the use of devices with the Echelon Neuron chip or its equivalent. LonWorks systems can start small and grow incrementally to powerful multi-site control networks by sending the messages over lans and wans.

If LonWorks was designed by a plumber then BACnet was designed by a committee of computer geeks. The basis of BACnet is the abstraction of the real world into a number of software objects which when assembled correctly simulate the behaviour of a real-world item like a boiler or a fan. Describing one of these devices in BACnet is a bit like describing a car by its components (take one engine, add four wheels, connect together with a transmission train, etc, etc). To get the most out of BACnet system, a central control computer is almost essential. BACnet took eight years of committee work to develop and during that time the preferred target networking technology, ARCnet, got trounced by TCP/IP and Ethernet. So BACnet/IP was developed and is now the most common variant found.

By investing in a technology that is open and adaptable, owners, operators and occupants will reap the benefit for many years to come.

  The general feeling is that LonWorks is superior at the field bus level to connect simple devices to form more complex systems. BACnet comes into its own where its schedules and logic can automate operations between complex sub-systems. At management level, one usually finds bespoke software to implement the man/machine interface. Today this is usually some sort of graphical user interface with a database which represent the facilities and systems being controlled. This is where Niagara and XML are making their mark.

Niagara is a Java based framework which allows a number of 'plug-ins'. These correspond to incompatible subsystems that can then be integrated together under Niagara. LonWorks and BACnet do not directly interact but both can be operated and integrated using Niagara. Different databases may also be logically connected. For example, events from many different incompatible systems can all be logged in a preferred database format and controlled from one graphical screen. In this way users can continue to exploit legacy systems while ordering best of breed new equipment from any source without worrying about interoperability. Niagara can almost be viewed as universal adapter for building automation systems.

Niagara was designed specifically for the building systems market. XML however is the latest hot technology from IT. Integrating computer systems has historically been a nightmare. In some cases company mergers have been abandoned due to extreme incompatibility between computer systems. Many companies have legacy applications that have hundreds of man-years of development tied up in them. Rewriting them in more modern languages is often not an option due to cost. Yet a large amount of value is locked in the old system. There is also an increasing need for company systems to integrate closer with those from suppliers, customers and agencies. To achieve this required a radical new approach: XML/web services. because of the investment already made (Microsoft alone has spent over $9 billion on XML technology) this leverages the immense power of the Internet and its technologies to achieve integration and interoperability. Web services use XML extensively and there are many powerful software tools available to integrate disparate building systems.

Rising to the challenge
These developments come at a fortunate moment as energy use and changing work practices put new pressures on building services. In the US there is a developing energy crisis, which will come to Europe shortly. At first sight energy should not be a problem in America. However, recent sharp increases in energy costs, added to distribution bottlenecks, have prompted change. Instead of running lights and chillers flat-out companies are looking for ways to economise. Facilities represent a large part of the fixed costs of most firms. With static sales and squeezed margins companies are looking at ways to use space more efficiently. Combine this with a requirement for more agreeable workplaces plus an increased level of security and the need for integrated, intelligent buildings where people can work efficiently and safely becomes imperative.

Studies show that employees are positively motivated by an environment where they can control their personal space to a high degree. Heat, light, humidity and ambient noise all influence worker output. Only an intelligent building with flexible, networked systems controlled by powerful software can provide individual employee comfort while controlling corporate expenses and security.