The use of open systems controls technology is increasingly being proven as cost-effective and viable.
As buildings have evolved with technology, the controls that run them have progressed from analogue systems to the networked, microprocessor-based systems now common in many commercial buildings.

Open systems offer low-cost network communications technology, creating the possibility of distributed and integrated control of the whole building.

Foremost among the contenders for a widely-adopted open systems standard is Lonworks, which is supported by over 3500 manufacturers worldwide, and already embedded in at least some of the controller products available from all the major controls companies. Other possible solutions are EIB and CAN.

As multi-vendor suppliers, controls specialists can mix and match products from different suppliers, combining them to suit the needs and budgets of particular projects. They can also interconnect the devices to create interoperable systems.

  There is an ever-widening choice of open products on the market. As new devices are launched, so the price of controller I/O has fallen significantly. For example, in 1998 there was no obviously viable Lonworks-compatible open supervisor, but the introduction of the OSS 2000 from Image, and developments in TAC's Vista program, have given Lonworks systems front-end functionality ahead of proprietary products.

Also, until 1999 there was no open systems solution for time control and optimisation at a network level, but Sontay Open Systems' LN-SCH open scheduler modules have filled that gap. Truly open systems can now be achieved, providing choices for contractors and end-users.

With the growing acceptance of this open standard, Lonworks technology is increasingly being integrated into building plant. This allows equipment to be delivered pretested to site and joined to a common network in the same way that it is connected to the power supply. An additional benefit is the integration of the various systems in a building.

These advantages are now being harnessed to the Internet, backed by world-leading companies, such as Cisco. Occurring simultaneously with the migration to open systems is a change in the way the data from such systems is accessed. IT increasingly allows easy routing of data from the control system to almost anywhere using standard IP protocols. A new breed of products enables this approach, such as Echelon's I-LON embedded web server, or the Open Supervisor software OSS2000. With these products, only a pc browser connected via a lan or wan is required to interact with the system. This ensures that the right control system information is available where and when it is needed.

Technology and innovation continues to reveal new control possibilities with open systems. At the same time, Lonworks product, installation and maintenance costs continue to fall.

What’s new in controls

Exodus Electronic has appointed Novaspec to manufacture its lighting control system, which encompasses three different receivers facilitating control of linear and compact fluorescent lamps. Invensys claims its Digistat RF roomstats now use a stronger signal and therefore offer an “even greater operating range”. They are said to be particularly valuable in large and steel-framed buildings, which tend to absorb radio waves. Eurotherm has launched a multi-function control and display product called Visual Supervisor. It is “a process controller, data logger, setpoint programmer and interactive touch-screen display in one unit”. A new binary input device from Siemens Instabus EIB, UP220/02, is designed for use with box mounts. This means that any conventional switch or push-button can be used as an intelligent EIB switch, including shallow profile switches. Leuze Mayser electronic has launched a miniature interface controller – bringing added functionality to safety systems. It also “adds functionality to certain equipment, improving productivity and reducing costs without sacrificing safety”. Sontay has introduced its BL BusLink cabling range of LonWorks building control systems. The new series offers “an innovative pre-designed approach to system wiring, saving engineers up to 25%”. Dätwyler has launched Ecobus, a building management cabling system for intelligent buildings. It is said to be an open system, allowing any manufacturer’s products to operate on the same cable.

Source

Electrical and Mechanical Contractor

Postscript

Phil Longhurst is business development manager at Sontay Open Systems.