Omron, Dome’u serin bir yer haline getirmektedir

Milenyum Dome, Londra’nın yakın tarihindeki en büyük projelerden biridir ve şehrin önemli yapılarından biri olmak üzere tasarlanmıştır. Yüzbinlerce ziyaretçinin gelmesini bekleyen proje mimarları, Dome’un mühendislik açısından mükemmeliğinin binanın sistemlerine ve altyapısına aynen yansıması konusunda anlaşılabilir bir şekilde titiz davranmışlardır. Mimarların özellikle önem verdikleri bir konu da bina içindeki klima sistemidir.

A deceptively simple control system The specification for the climate control system is built around 36 roof vents, which were to open to various positions - in reaction to rising or falling temperatures - to adjust ventilation, and which were to close automatically in the event of rain. A manufacturer of screwjacks was commissioned to provide the actuators for the vents, and the manufacturer recommended Lintran as a systems specialist to provide the motive force and the associated control systems. Lintran was approved by the primary contractor, British Aluminium, and the dome architects, and the contract was awarded.

The construction of the Dome and the requirements for ventilation offered some key challenges. A particular problem was the location of the vents - hardwiring the motor/drives to control the screwjacks would have involved tens of thousands of metres of cable, which would have been unsightly, heavy, very difficult to install, and expensive. Instead, Lintran was keen to use a two-wire, twisted pair remote I/O network, which would be cost effective, reliable and expandable. To meet its needs in terms of control components and networking capability, Lintran turned to Omron.

Working together, Lintran and Omron devised a control system that was deceptively simple. A motor, driven by a softstart, actuates each screwjack. The vents can be actuated to any of four positions: either closed, or open at 25o, 50o or 75o. The softstarts are networked on the two-wire link to an Omron SRM1 PLC - a micro PLC little bigger than a matchbox that combines high speed control with the ability to act as a bus master, offering the capability to handle up to 256 remote I/O. As well as the softstarts, the remote I/O link also extends to the sensors which provide the positional information on each vent. Compact and flexible, the SRM1 provided a highly capable and cost effective means of controlling the roof vents.

Each C200H's PLC is connected to an Omron NT30 MMI. The full colour, touch screen HMIs made it easy to program the vent actuation, as well as providing excellent monitoring stations for the Dome temperature and associated systems, where operators could see the status of every zone at a glance.

"We were able to simulate the system at our own premises before taking it on site," Chalk continues, "so we were confident that the control architecture would meet the Dome's climate control requirements."

Despite the precarious position of the installation team, experience had taught Lintran to be confident in the Omron equipment. Chalk comments: "Omron products are always reliable, and because Omron controls the support of its products, the company can offer a better service - and there are plenty of people on the ground to help with enquiries and problems.