An interlocking control system A facilities management system interlocks the pieces of the system-control puzzle at Legoland to ensure a safe and entertaining day at the park.

As you walk through the gates of Legoland, you're greeted by a dinosaur made entirely of plastic bricks. It peers over a rolling hillside toward Windsor

An interlocking control systemA facilities management system interlocks the pieces of the system-control puzzle at Legoland to ensure a safe and entertaining day at the park.

Dec 20, 1996 12:00 PM, Simon ForrestForrest is with Phoenix Communications in London, England, and was bid consultant and

As you walk through the gates of Legoland, you're greeted by a dinosaur made entirely of plastic bricks. It peers over a rolling hillside toward Windsor Castle, home to Britain's royal family. And spread out before the dinosaur's feet is a colorful world of pirates, robots, musical waterworks, rides, shows - and, of course, Lego.

Lego is a wonderful thing. These small, interlocking plastic bricks become the most fantastic of creations. The same few bricks will be a robot today, a palace tomorrow, the next day a space ship or a dragon or maybe a submarine. And this sense of fun, of fantasy, of creativity and of learning is at the heart of the Legoland experience. The new park at Windsor, in southeast England, opened on March 29 and is a realization on a huge scale of the Lego ethos of entertainment and education.

Twenty-five million Lego bricks make this park a showcase for both Lego and modern theme park design. The park, with a young target audience, emphasizes participation and education. Legoland has no white-knuckle rides; the rides are designed specifically for preteens rather than older children and adults. It offers its guests an experience to be enjoyed at many levels, mixing the excitement of rides and adventurous activities with the delightful wit of Miniland, where the sights and sounds of Europe come to tiny life. Kids move from live music and stunt shows to hands-on, computer-based fun.

Technology in actionLego wanted a control and communications system to keep the staff in touch with everything going on in the park. Known as the building and attraction management system (BAMS), this system replaces the individual controls of a diverse communication system with a unified operator interface, providing all functions on a single console and supplying all communication paths through a shared route. This allows nonspecialist operators to concentrate on coordinating the park's activities and maximizing guests' enjoyment without struggling against the technology.

The BAMS concept calls for the control and monitoring of the park communications and security subsystems, each with its own proprietary hardware and software, including:

* Public address, with both live and digitally prerecorded announcements.* Fire alarm, with the automatic evacuations on alarm detection.* CCTV, with control of pan-tilt-zoom cameras, time-lapse and spot recorders and multiplexed displays.* Access control at staff entrances to the site and to secure areas.* Security alarm monitoring with a range of detectors, such as IR, contact and seismic.* Lego attractions - the rides and models.* Office and electronic point of sale (EPOS) LANs.* Telephone with quick dial numbers and call logging.* Personal mobile radio for site communications.* Site-wide radio paging using alphanumeric messages.* E-mail with automatic messaging to maintenance staff and park management.* Internal fault monitoring of the BAMS and subsystem communications.

The interface makes the operator's job easier by providing a consistent link to every system from a single spot. One operator can monitor all subsystems within the park and act as the focus for park-wide communications. A combination of automated and operator-initiated responses to external events coordinates control with Lego personnel, security, maintenance, attractions and entertainment staff; with the general public; and with outside services, such as fire, police and ambulance.

The operator controls and monitors the subsystems using a touchscreen display, which shows a scale representation of the park. Information is presented in an easy-to-assimilate graphical format with the same intuitive on-screen tools, icons and procedures for the different subsystems. Instructions are in everyday language, and control is by means of on-screen buttons. In addition to the touchscreen, two adjacent monitors display CCTV pictures, and the operator has a headset combining earphone and microphone for use with the PA, radio and telephone systems.

The system prompts the operators to respond to events appropriately. A system activity log is kept automatically, and operators can acknowledge alarm and fault conditions and add commentary by way of the keyboard. Events occurring in one subsystem can initiate responses from other systems without operator intervention. Intercommunication among the different subsystems is seamlessly presented to the user, with all protocol differences and contentions resolved by the BAMS itself.

The BAMS is part of the overall telecommunications infrastructure package for Legoland. Carter-Voce Ltd. and Westinghouse Cubic Ltd. designed and installed the system, and telecommunications consultants Mott MacDonald produced the specifications.

Whatever Lego wantsLego required an all-embracing communications and park management system, one based on state-of-the-art but proven technology. This had to be married to a record of established design and installation skills. With its background in both audio communications and security, Carter-Voce had the system-building experience necessary to take on a project of this scope.

VxLAN was originally considered only for the control and monitoring of the public address and fire detection systems, but as the scope of the BAMS package expanded, other parkwide systems, including CCTV and access control, were integrated into a common management system.

"The engineers heading up the Legoland project went into it straight from another VxLAN installation at the Glasgow Royal Concert Hall, where VxLAN runs the Hall's voice alarm system," said Neil Voce, managing director of Carter-Voce. "We've worked with VxLAN for a number of years now, and we know where its strengths lie when it comes to integrating large distributed sites with many subsystems."

VxLAN's graphical interface with touchscreen operation gave Legoland the required usability. Operators could perform a range of tasks, including park management during the park's open season and covering security throughout the year.

Carter-Voce's experience of installing VxLAN as a life-safety voice alarm system also guaranteed that the end-product would offer the resilience and redundancy required by the park's very demanding specification.

The importance of cooperation and coordination with other companies working on a project like this is often overlooked in favor of the hardware interfaces. But smooth interaction at the company level is always a major factor of a successful project. Carter-Voce committed key staff for the lifetime of the project, ensuring continuity throughout the design, installation, commissioning and support stages.

Ready, set, buildLegoland is built on the site of the old Windsor Safari Park, but the site was redeveloped with new infrastructure and services. Legoland is organized as a series of separate but interlinked activities, with its core attractions within five main activity areas separated by landscaping. The five activity areas are The Beginning, Imagination Center and Miniland, Duplo Gardens and Lego Traffic, My Town and Wild Woods. The three staff areas are the control room, the security area and the equipment room.

For BAMS purposes, these eight areas are known as clusters. Each cluster has one or more equipment racks, or cluster distributors, containing the BAMS hardware. Many building distributors contain active equipment, but most of the distributors are the point of entry for structured cabling.

BAMS is the main part of the Legoland telecommunications infrastructure, based on a generic structured cabling model (reference ISO 11801). This setup uses a primary infrastructure of a dual-redundant, site-wide fiber optic ring to the cluster distributors and a star topography secondary infrastructure feeding the individual building distributors in category 5 copper and fiber cables.

The fiber backbone is made with a 1.36 mile (2.2 km) ring of 64 cores of 62.5/125m multimode fiber, which carry all of the main park communication and security services, including:* Public address.* Fire detection.* Closed circuit television.* Access control.* Security alarms.* Telephone.* Office LAN.* Electronic point of sale LAN.* VxLAN.

The eight cluster distributors house most of the active transmission equipment on the site and form the main interface between BAMS and the subsystems. Dedicated fibers and interface equipment provide additional communications, as required.

Within the clusters, copper-structured cabling from the distributors serves mainly the telephone, office LAN and POS LAN systems. To meet various life-safety and security regulations, the other systems use their own cabling back to the cluster distributors. For example, the PA and fire detection systems come back to the clusters in low-smoke and -fume, zero halogen cable, which meets the requirements of the UK fire and voice alarm standard, BS5839. Connections between equipment and the structured cabling are via patch panels to facilitate rerouting and maintenance.

All about VxLANEach cluster has a VxLAN outstation, which distributes the control and monitoring data and the site-wide audio. The VxLAN system comprises the front-end Windows touchscreen software and a network of outstations that route, transmit and collect data from around the site. At its simplest, a VxLAN system can be a single intelligent outstation with on-board processing for all event handling, routing and automated responses.

At Legoland, eight distributed outstations have two independent controlling PCs. The VxLAN outstations are based on modular, open-architecture embedded controllers designed to the established STEbus industrial standard with high proven reliability. The outstations use a range of processor, networking, input and output boards. Legoland emphasizes data collection and transmission rather than localized intelligence. So here, the outstations format their inputs and outputs into a common network protocol and provide data integrity and network monitoring, otherwise acting as a transparent medium between the PCs and the subsystem hardware.

Majid Siadat and Tim Bierman designed the network hardware and software.

"Although we can supply standard units with user-configurable software for smaller sites where only public address and voice alarm facilities are required, a system of this size is not off-the-shelf," Siadat said. "If you're building a stadium or a museum, you don't expect to take delivery of a pile of black boxes, wire them together and be in business. You're buying the skill and experience to design the right system and to support it through commissioning, training and documentation as much as you're buying hardware and software.

"Modular units offer a much greater range of functions at a cost-effective price. We've got no need to design a single all-encompassing unit with the overhead of design and component cost. You only get the functions required for the project so you don't pay for unnecessary features. And more functions can always be added later."

With a linked, integrated system, support costs are lower because replacement parts are just that, and the entire system doesn't need to be replaced, Siadat said.

Data distributionThe cluster distributors have two types of interfaces. Some of the systems, such as PA and fire detection, connect directly into VxLAN outstations, which route their signals around the park.

The other systems, such as CCTV and LAN, use their own fiber hubs and drivers to transmit onto the fiber backbone. They collect and route their own data and interface to VxLAN in only one or two locations. The CCTV is connected to VxLAN at the equipment room, where all of the centralized CCTV equipment is housed. The security system interfaces with VxLAN at the control operations center and the security offices to provide alternate paths during a system failure.

The VxLANoutstations are connected by a dual redundant asynchronous serial network running over clockwise and anticlockwise fiber rings, and all VxLAN transmissions are broadcast on both fiber rings. Outstations receive data from one ring. If transmission is lost on the current ring or if the error rate goes above an acceptable limit, an outstation automatically switches to the other ring in order to re-establish communications. This switchover is transparent to the operator and happens without any manual intervention, but all faults and recoveries are then reported back to the operator, making the faulty cable segment very easy to identify, and thus fix.

The outstations at the operations center and the security control area are master controllers on the network. They are each capable of independent control of the timing and transmission protocol of the network, providing redundancy and resolving their own contentions. If one of these masters fails, the other one automatically takes over as the active master. The master outstations interface with the VxLAN PCs by a serial data link and provide the connection between the BAMS operators and the VxLAN network.

The other outstations are data gathering and distribution nodes that read and report the status of contacts from external subsystems via opto-isolated inputs. They control external subsystems via volt-free relay contacts that can be hardware configured to operate as normally open or closed and by serial interfaces that transparently pass serial information to and from the VxLAN PCs over the network. The VxLAN network provides a maximum of 32 serial channels, one used by the network itself for internal communications. The other 31 are available for interfacing with external systems. At Legoland, the outstations have either two or six serial ports depending on the connections required at each of the locations.

In addition to the data communications performed by the VxLAN outstations, they act as audio distributors to transmit audio signals around the site for the public address system. The audio network operates over separate dual redundant counter-rotating fiber rings. As with the data communications, each outstation listens to one fiber ring by default. If it loses signal or receives a signal with too high an error rate, it automatically switches to the other ring and informs the operator of the fault.

The outstations at the control center, the security area and the equipment room are master audio interfaces. They offer both audio inputs and audio outputs, with matrixing capabilities to route inputs and outputs as required. They encode analog audio to digital format and provide the audio feeds to the PA system. The network also provides the audio links between the operator headsets and the radio and telephone systems, with digital encoding and decoding for transmission over the fiber.

The other VxLAN outstations receive the digital transmission and decode it back to analog audio. This is then sent to the PA system as a 0 dB into 600 V audio input. As standard, VxLAN provides up to six simultaneous digital audio channels on each fiber ring at resolutions from 8 to 24 bit. At Legoland, two high-resolution audio channels provide high-quality audio for internal and external announcements.

One BAMS operator console is in the control center for operation during park opening hours, and the other is in the security area for operation after hours. The BAMS consoles are based on high-grade industrial PCs, which offer high reliability compared to commercial grade PCs. They maintain the required mean time between failures (MTBF) figures for the site much more efficiently.

The consoles comprise a VxLAN 486DX4-100 19 inch (483 mm) rackmount PC, a 20 inch (508 mm) capacitive touchscreen running at a resolution of 1,024—768, a high-quality headset microphone (50 Hz to 15 kHz bandwidth) and two 20 inch (508 mm) color CCTV monitors. Both consoles are connected by serial link to their respective VxLAN master outstations and by Ethernet to their own LAN (Microsoft Windows) and to the security LAN (Novell Netware). Both consoles have a laser printer for report printing; the console at the control center contains a tape streamer for software and database back-up.

Because VxLAN is the key to Legoland's communications and security, reliable and resilient performance are essential. The two touchscreen control positions have control duplication and automatic handover in case of a fault. To back up this full redundancy, a diagnostics modem allows engineers to dial up the system remotely, monitor its performance down to the status of every relay, and, if necessary, reconfigure the system on the fly by downloading new software into the outstations. This allows Legoland to have expert coverage 24 hours a day without on-site engineers and reduces long-term support and training costs for the system.

VxLAN Windows softwareThe Legoland BAMS is based on an extension of the existing VxLAN hardware technology. The software specification is a substantial advance on the current VxLAN system, and a new package running under Windows '95 has been developed to meet the wide-ranging requirements of the BAMS.

The VxLAN Windows-based front-end software is written using the EZFM graphical tool kit from interMETHODS. This provides a multileveled graphical display showing all areas of the site in overview and detail, with interactive data-aware objects representing the devices around the site (PA amplifiers, CCTV cameras, access-controlled doors, fire detectors, mains supplies, Lego models), and an event-handling engine for configuring automatic system and operator-prompted actions.

Jeff White, director of interMETHODS and head of its design team, said "The advantage of a development environment like EZFM is that it offers great flexibility in setting up the interfaces to external systems and establishing the interactions between events. It allows very rapid development of visual prototypes so clients can see what they're getting at an early stage in the contract. This is essential; you need client feedback throughout the project so you can avoid last-minute changes, which bring in extra costs and delays. With this sort of flexible system, you can get a working front end very quickly and fill in the fine details of the interactions between subsystems as the project advances."

From an operations point of view, the client is looking at what the system is saying and how the client can respond to these events. The clients want to know as much as possible about the status of the park's many systems, and they want timely information about specific events, such as fire detectors showing an alarm condition or security devices picking up an intruder. But presentation of status and event data has to be balanced against usability of the system. Show the operator too much and response times slow down because the operator has to pick out the required information. Even more dangerous, critical events may be overlooked, hidden by the greater number of routine events.

To overcome this, VxLAN presents information to the operator at various levels and accommodates automatic responses where a delay might be critical. New events are highlighted visually and audibly, and instructions suggest appropriate responses. The same event can initiate system actions automatically or when the operator acknowledges the event. For example, a fire detector can initiate a digitally recorded message via the public address system in the zone affected, or a security alarm can select a camera to focus on the area where the breach occurred, record the intruder on a VCR and page security staff to advise them of the breach.

As well as responding to external events, the operator can initiate actions on any of the controlled subsystems, such as making PA announcements, selecting and zooming CCTV cameras, recording and playing back videotapes, locking and unlocking doors or contacting staff by radio, telephone, pager or e-mail.

System status is monitored by checking the status of individual devices, by checking a log of all devices currently in fault or alarm or by checking the audit log that records all events and operator actions.

System integrationSo how does VxLAN handle integration among the different subsystems? First, it presents the controls for subsystems and all status information in a common format. Second, it automatically handles as much of the interaction between the systems as possible.

Each of the subsystems has its own protocol and format for control and monitoring. To simplify the operator's task, VxLAN handles all the protocol translation and imposes a common format on the presentation of controls and status information. All controls are based on simple one-touch operations without needing a keyboard or drop-down menus. (Have you ever tried to activate menus on a touchscreen, let alone double click on an icon?)

Real-world hardware is represented by interactive icons on the screen, which can be used to bring up suitable controls. For example, a window with pan, tilt, zoom and focus controls a CCTV camera and provides access status information about the device. Although the information presented varies from device to device, the procedure to bring up the information is the same for every piece of hardware, whatever the manufacturer and nature of the physical interface.

By imposing a common standard of presentation onto all subsystems, VxLAN simplifies the learning process for new operators and allows operators to deal with the park as a whole rather than with individual systems. A small number of basic operations can be applied across all the subsystems, such as touching a device icon on the screen to activate its associated controls, disabling or enabling a device with a single button and so on. All control buttons have a simple descriptive legend, avoiding technical jargon wherever possible, and this is backed up by an icon visually indicating the control function.

Unlike, say, a typical CCTV keyboard, the operator does not have to remember the command abbreviations, device code numbers and command sequences required for each operation. From the overview of the site, the operator can touch the area containing the device he wants to control and zoom to the area's map. The icon for the device itself can then be touched to bring up the relevant controls. A camera icon shows which way the camera is pointing and whether it is fixed or can be panned. All the controls applicable to that device are shown, and each control can be activated by a single touch.

With CCTV, for example, controls for pan, tilt and zoom are only shown for cameras with this feature. Preset camera views identify what will be shown by name and icon rather than by number. Buttons leading directly to associated controls are also shown. On the control window for a camera are buttons for the CCTV monitors and the real-time VCR. This means that the operator doesn't have to know in advance the features available for each device. Each device reveals its own capabilities when accessed.

This common style of presentation is applied beyond the device controls and monitoring to all operator functions. Current faults and alarms can be viewed in a single list, as can a historical log of all events, with filtering by event type, device name, operator, date and time, etc. The operator can review an event by bringing up the original message box relating to it; any operator comment typed in at the time is also shown. To check which device was involved, the operator can press a button to zoom to the relevant map with the device icon highlighted, which supplements the text description of the icon's location and uses the same visual links as the original event.

This simple, intuitive and graphical icon-led control interface is backed up by a powerful event-handling engine used to program automatic responses to events. Each event can initiate a range of different actions, and each type of action can be initiated by one or more events. This gives VxLAN great power and flexibility in automatically responding to events, allowing the operator to concentrate on coordinating human response to the event. And, of course, it means that if the operator is otherwise engaged at the time, the event is not ignored; the system makes most of the vital responses itself.

It might seem that this level of flexibility and power must carry with it an extensive overhead of complex programming and configuration. This is where the real beauty of VxLAN lies: the system administration tools that allow devices to be located on maps, addresses for device monitoring to be set and interactions to be programmed. Using the built-in graphical tool kit, VxLAN can be set up without any knowledge of programming. Anyone who has enough familiarity with Windows to format a word processing document or set up a spreadsheet can work with VxLAN. And the same format is used whatever the device type and however VxLAN receives the data: as bit data from direct contacts at outstations, as serial data from an intelligent device or via a DLL software interface.

Coming soonRegarding the future of integration projects like Legoland, Voce said, "We believe graphical systems such as VxLAN will be the main driving force behind the expansion of the integrated systems market. A package like VxLAN is powerful enough to handle large site requirements, as at Legoland, but it doesn't come with either the price tag or the steep learning curve often associated with integration at this level. This means we can look at using the system across the whole scale of projects, from single buildings up to multisite installations. As affordable, dependable systems like VxLAN become available, clients will be able to achieve very high levels of integration while knowing that they're dealing with proven hardware and software, not a custom-built, and therefore potentially risky, system. And mainstream contractors will be able to take on these projects without having to hire expensive digital engineers and software programmers."

As with all integrated systems, the real skill is in knowing what devices to install and what interactions to set up. This is where the expertise of the systems designer comes in to play: a grasp of the big picture with a working knowledge of all the subsystems involved so all system devices can be linked intelligently. Once these decisions are made, VxLAN is an excellent tool to vastly simplify the actual implementation and fine-tuning of integration.

Tweaking the systemNeedless to say, fine-tuning is an ongoing task. At Legoland it continues beyond the opening of the park. The system is being refined as operational requirements change because of the experiences of running the park live with its thousands of guests behaving in ways which no scenario or model could exactly predict. Using VxLAN, the BAMS grows alongside the park. Devices can be added, even while the system is online, and interactions can be changed quickly and smoothly without any operational downtime.

SubsystemsThe BAMS interfaces with a number of subsystems and includes everything from comprehensive control of all aspects of the subsystem to simple status monitoring.

* Public address: Audio is transmitted from the operator headsets and the centrally located DVA via the VxLAN audio network to TOA PA racks in the cluster distributors. VxLAN controls switching and routing to the clusters to address individual zones, groups of zones or the whole park. Zone selection is made by touching the specific area to be addressed on the screen, with shortcut buttons available for selecting whole clusters or the whole park.

In addition to the internal PA zones covering all the park's buildings, a parkwide system addresses only the external areas. This is signal-delayed down the park to provide coherent audio in all areas. Software interlocking prevents external delayed zones being addressed at the same time as internal nondelayed zones.

* Fire detection: VxLAN monitors the Wormald fire detection system and provides operator prompts in the case of either a fire alarm or a fault in the fire detection system. When a fire alarm is sounded, the screen zooms to the area on the map affected, highlights the zone in red and selects it for PA announcements while automatically clearing any other previously selected PA zones. The operator has a preset time to make manual announcements before the local recorded evacuation announcement begins.

* Closed circuit television: The site is monitored via the two CCTV monitors at each console. Camera selection is made by touching the required camera on the VxLAN screen, with options for full screen and quad displays.

Pan, tilt and zoom (PTZ) cameras are operated by on-screen controls with buttons for pan, tilt, zoom, focus, lamps, wash-wipe, etc. PTZ cameras can also be moved to preset views at the touch of a button.

All cameras record on time-lapse VCRs, with spot recording of events on a real-time VCR. Automatic event recording begins with the sounding of alarms from the security system. VxLAN selects the relevant camera, zooms it to a preset, if appropriate, and begins recording, all with no operator intervention.

The operator has complete control of playback from the VCRs for immediate review of incidents, with the VxLAN handling automatic switchover to a standby recorder to ensure all cameras are recorded at all times.

The two BAMS consoles have independent selection of the cameras displayed on their respective monitors at the control center and the security area. Only the active operator has control of the PTZ functions and the VCRs in order to prevent conflict.

The CCTV routing and transmission system is manufactured by COE, and VxLAN interfaces to the COE Telecommand matrix to control switching, recording, multiplexing, etc. Advanced recording functions are available by addressing the Mitsubishi VCRs directly.

* Access control and alarm monitoring: The access and alarm monitoring security systems have comprehensive monitoring and control. Alarms, tampers and faults are immediately reported to the operator, who receives instructional prompts for responses. As noted above, certain security alarms initiate automatic recording by the CCTV system.

Security devices can be remotely enabled and disabled from VxLAN with suitable operator authority, and the system can provide a list of all devices in alarm, tamper or other abnormal conditions.

A database of card-holders is available for up to 10,000 staff members with full control of details such as access levels, PIN codes and validation periods. The system offers remote updating and batch processing of the access control database and remote validation and registration of access control swipe cards.

An interface between the VxLAN software and the StarWatch security software from Remsdaq handles the security events and database management.

* Lego attractions: VxLAN is designed to monitor safety-critical and -noncritical alarms at the many attractions around the park, but these are not yet fully implemented. More extensive control of the attractions will be integrated into VxLAN in the future, providing building and energy management services within the scope of the overall parkwide management system.

* Telephone: An on-screen keypad has dialing with a quick-dial database of commonly used numbers. The operator headsets are used as telephone headsets with an interface to the SDX exchange through a custom DTMF interface.

The telephone allows the operator to contact the emergency services in the event of a fire or other emergency situation, and both incoming and outgoing calls are enabled.

In addition, the VxLAN event log provides a record of calls as part of its comprehensive audit trail of all operator and automatic system events.

* Radio: VxLAN is able to monitor and broadcast on any of the three radio channels through the operator headsets to provide communication facilities for the park staff, who use Motorola handheld radios.

* Radio paging: VxLAN has the facility to manually or automatically page maintenance, security, operations and attractions staff on a Philips site-wide paging system, telling them of faults and alarms as they occur. Each event can send a different preprogrammed message to the relevant groups of pagers.

Both the radio and radio paging facilities have been provided in accordance with the specification but have not yet been taken up by Legoland because of subsequent operational decisions.

* Office and electronic point-of-sale LANs: VxLAN can monitor hardware fault conditions on the Ethernet hubs at each cluster distributor. A future development is to install a network bridge to allow VxLAN direct access to the office LAN for e-mail, network printing, database back-up to the network server and so forth.

* VxLAN: VxLAN provides monitoring of its own hardware and the fiber rings connecting the outstations with a range of faults identified and reported back to the operators. A continuous dialog between the two VxLAN PCs provides automatic hand-over from one BAMS console to the other in the event of a fault.

VxLAN also maintains its own Ethernet LAN connection between the two VxLAN PCs for use by internal operations and for synchronization of the security system databases.

The use of this unified operator interface allows the park to control and communicate with everything going on in the park. The result is an easy-to-use system that allows operators to concentrate on the park, not the hardware.

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