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Lightning and power protection

Why duplicate wiring, sensors and engineering quite unnecessarily? Occupancy schedules and infrared sensors might be used by an environmental control system to run the hvac, and could also be employed to switch the lighting controls. And, if someone was in the wrong place at the wrong time, the security system as well.

Then again, the same occupancy information might be used by life safety systems to provide 'intelligent' smoke control. At first glance, the applications of this approach appear to be almost limitless. In theory, such integration offers the user more sophisticated control and more highly automated systems.

Attractive? Maybe. But do users actually want it?

Software integration tools have been around for many years and some of these allow a host of different proprietary systems, network architectures and communications protocols to be meshed together. But in the majority of applications, there is very little 'cross functionality' or overlap between building systems.

Free-standing entities

This is not too surprising as most building systems are designed to operate as free-standing entities. Indeed, they have emerged from industries which are, by tradition, separate specialisms - hvac, fire, security, etc - and were all developed in isolation.

As a result, even in the most highly serviced 'intelligent' building, out of thousands of connected control and monitoring points, the requirement for integration seldom extends to more than a handful. The only times when integration is essential is when systems depend on each other for common data and so need to be 'mapped' together.

For example, a life safety system may need to inform the hvac control system of a smoke condition so the latter can disable the air handlers as the smoke dampers close. However, the amount of integration is minimal when compared to the overall size of the services installations. Indeed, it can usually be dealt with by either hardwired interlocks or a one-off custom interface between the two systems.

Integration between building systems, therefore, begins to look less like a major issue and more like a red herring.

However, there is one important area where building users often encounter problems and where the capabilities of integration equipment can be exploited to good effect. In many situations, the management of buildings has become cumbersome because of the sheer number of separate displays that are required.

The image of a control room littered with computer screens is familiar but, in the rush to advance technology, the system manufacturers may actually have created a rod for their own backs. Displays are normally designed by manufacturers for use on their own equipment, and information from other systems can rarely be introduced successfully.

Simplifying the display interface

Even though many displays can co-exist under the same software operating environment - such as Windows - each system display still has its own structure and array of functions, features and foibles. And the fact remains that each still has to be learned and used quite independently.

Few organisations can now afford the staffing costs or time to support this state of affairs, so finding a more rational approach has become a matter of hard economics, and simplifying the display interface is essential in order to reduce operational cost. So what is more important than continuing the debate about integration is the whole concept of making displays appropriate to the user.

Inappropriate displays cause untold problems, eg, night security guards locked in combat with feature-laden screens. To make any real progress with the management of buildings, the displays must acknowledge the divergence in the needs and services knowledge of potential users - and all unnecessary technical 'overheads' should be abolished.

Tools are now available which reduce the necessary skill level and design time to a level where custom displays can be entirely viable even for a single user on a single site. Of course, making display systems more appropriate is intrinsically linked to multisystem operation. In general, the end user does not care whether the luminaires are switched on by a lighting control system or the airconditioning controls - or both for that matter - as long as the display allows the information to be presented and used in a convenient and consistent way.

This raises the old question of compatibility. The way in which current display products achieve communication is via 'drivers' - that is, software modules that allow information from any combination of systems to be collected and displayed absolutely simultaneously.

But will system manufacturers go along with this?

The good news is that they already have. Sufficient numbers of manufacturers have already permitted drivers on to their systems to make this concept very viable. Communications techniques such as high-level networking - whereby each of the building's systems is connected to the display system by an ultra-fast high-capacity network - mean that it is not even necessary to alter existing field installation practices to bring systems back to a common display.

So, while building systems continue to develop and increase in both power and complexity, we now have the means to ensure that the operator interface becomes much more appropriate and much less cumbersome. For it is this, rather than integration, which remains a thorn in the side for most end users.

For more information contact Dennis Esmonde-White, TAC, 031 767 0201.

About the company: Northern Communications is a manufacturer and supplier of integration products which enable engineering companies to construct truly integrated building control systems. The company is represented locally by TAC.

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