IN CONTROL - Sound & Video Contractor


Imagine the control room of almost any industrial enterprise-telecommunications, power management, traffic control, emergency management. Each of these
Publish date:


May 1, 1999 12:00 PM, Amy Silverman

Imagine the control room of almost any industrialenterprise-telecommunications, power management, traffic control, emergencymanagement. Each of these critical nerve centers must handle large amountsof constantly changing visual data. The information arrives at the controlroom in a number ofdifferent forms-video from a satellite downlink, sensordata gathered from remote monitoring equipment or systems analysisapplications running on networked workstations. Although the data and theprocess being controlled will be different, there are a few corerequirements for such facilities.

First of all, visual data must be managed in a multitude of formats.Constructing a display system for one type of video is easy; for NTSCcomposite video only, simply set up a video switcher and a video monitor.What if you also have to deal with S-Video and digital video? What aboutthose VGA, SVGA, XGA and SXGA computer screens you need to switch in to thedisplay? Consideration must be given to every variety of visual informationused in the command center. Analog vs. digital, color space issues likeNTSC vs. RGB, interlace vs. non-interlace, resolution, and different scanand frame rates all must be addressed in the display system configurationplanning.

Moreover, the typical command center is staffed by numerous operationspersonnel. To create an effective communications environment, informationon individual workstations and video monitors must be, at times, madereadily available to all or part of the command center staff. Instead ofcrowding around a small screen intended for personal viewing,decision-makers can do their jobs more effectively if the information isinstead routed to a large screen.

A third requirement derives from the first two-the need for individualoperators to monitor multiple sources of visual data. Bombarded by avariety of video and computer sources, the operator must keep track of allinformation. If the data is combined onto one large screen or multi-screendisplay he will have a much easier time tracking it. Additionally, a largescreen solves the second requirement for sharing that information with therest of the staff.

Most control rooms also use a high ambient light environment mostly becauseof the need to read printed materials. Although it is an attractive goal,most businesses have not quite made the leap to a paperless office. Thereis also a general concern for the alertness of the control room operator. Areasonable amount of ambient light is usually desirable to maintain anattentive command staff. These lighting conditions can prove challengingfor projection and display equipment. The brightness of these devices mustbe enough to combat the ambient light conditions and provide sufficientlumens for a legible display.

Lastly, the majority of control rooms are managing processes without downtime. They must operate 24 hours a day, seven days a week. The water neverstops flowing, and the power never goes off. Just as the process has itsbackups and failsafe supports, so must the control room. To the systemscontractor designing the installation, this can mean planning for redundantsystems and a store of backup components to replace a downed system quickly.

All of these requirements, combined with technological advances in managingvideo images, have meant the evolution to a more high-tech approach forcontrol room information management. You might have walked into an electricpower command center 10 years ago and seen static displays with scalediagrams of the power system being hand marked with tape and pushpins toindicate downed lines and other system problems. Fortunately, improvementsin handling and displaying computer and video data have changed the face ofcommand centers. For companies looking to upgrade control facilities or addnew ones, there exists a large selection of image processing and displayequipment from which to build a sophisticated visual communications system.

RGB Spectrum, for example, manufactures a number of video processingdevices and subsystems used in control rooms and other A-V applications.The following examples illustrate how leading-edge processing and displayequipment can be used to fulfill the core requirements of the moderncommand center.

The 1996 OlympicsWhen the Georgia Power Company was named the official power source for the1996 Olympic Games, it needed a command center to monitor the flow of powerto allOlympic venues and track everything from weather to traffic flow to mediareports. To manage this information and support its pledge to keep thelights on, Georgia Power and its systems contractor, Insight Research,designed and constructed a control facility with two completely redundantsystems. Although the games have left Atlanta, the center is in use todayas a storm watch facility.

The cornerstone of the command center is the high-resolution, multi-screendisplay wall, constructed with 67 inch (1.7 m) rear screen projectors fromBarco and a ComputerWall processor from RGB Spectrum. The display wallallows the command center staff to view dozens of different computer andvideo signals at high resolution on a large screen for greatly enhancedvisibility. With the ComputerWall, one signal can be magnified and splitover all four projectors, maximizing the image visibility for the entireroom. Supporting the wall is a network of switching and scan doublingequipment, allowing a large number of computers and video sources to berouted to the display wall. All of the video sources are first line doubledto generate a flow of enhanced-resolution component RGB signals. Thesesignals can then be sent through the RGB switching equipment along with thevarious computer sources and selectively fed to the ComputerWall fordisplay on the 2x2 wall of rear screen projectors.

Traffic managementIn the Los Angeles Automated Traffic Surveillance and Control Center(ATSAC), the application calls for mixing video and computer inputs intheir native formats on a single display, as opposed to line doublers. TheATSAC operations center was built to manage traffic in the city limits andon the Smart Corridor of the Santa Monica Freeway. By using a variety ofelectronic surveillance and detection systems, including video cameras,traffic engineers can pinpoint and solve problems more quickly and keeptraffic flowing.

American Video Communications, Los Alamitos, CA, designed and installedthis control room. The facility uses seven data grade CRT projectors on 67inch (1.7 m) rear screens. With the addition of RGB's SuperView windowingsystems, the center can show live video feeds, computer-generated trafficgrids and maps all on each large screen display. As events warrant, eachsource can be sized from a small window up to full screen for closerinspection. Being able to show multiple inputs on a single display makesthe individual operator's job easier. Instead of monitoring severalscreens, thereby increasing the likelihood of missing potentially criticalevents, vital information is kept on one screen.

The technology used in these control rooms continues to evolve, and systemsintegrators need to keep educating themselves on these advancements.Improvements in projector technology have delivered a slew of new productswith expanded specifications and functions to the visual communicationscustomer. The traditional display choice, a CRT projector or monitor, hasbecome increasingly challenged by such new discrete pixel technologies asDLP and LCD. These devices offer the benefit of higher output brightnessand a smaller, lighter form factor.

These discrete pixel projectors, however, lack the flexibility of CRTtechnology in accepting a wide variety of RGB signals. They have a nativeresolution and limited acceptance ranges for horizontal scan rate andvertical refresh rate. When selecting a fixed-resolution device,distinguish between the native resolution and compatible resolution range.The native resolution refers to the fixed array of pixels of the mechanism,but the compatible resolution range means that anything in the range can bemanaged, but it will be scaled by the projector's internal electronics.Most newer models have integrated decoding and scaling electronics, but thequality and precision of the translation varies among projectors and frominput to input. Thus, it is often necessary to consider pre-processingsignals prior to the projector so that they conform to the nativeresolution and preferred sync rates of the discrete pixel device.

For video sources, this pre-processing is achieved with line doublers.Traditional line doublers have been steadily advancing to higher qualitydigital video scalars, with the flexibility of taking video and scaling itup to the native resolution of the target display device. Previousgenerations of doublers use one of two approaches. One replicates each lineof video, giving an output that is free of motion artifacts but has lowvertical resolution. The other approach merges two interlaced fields toprovide a frame, preserving full vertical resolution but generating asevere feathering effect on moving objects. Digital video scalars applymotion detection and high-order interpolation algorithms to preserve fullvertical resolution with minimal motion artifacts. The precise scaling ofthe output signal means it can be tailored to the requirements of thedisplay. Video can be doubled, tripled, quadrupled or set to any line countand frame rate desired.

To match computer signals to the fixed resolution of DLP and LCDprojectors, there are RGB up and down converters. Once again, thispre-processing avoids activating the projectors' electronics, consequentlyyielding higher image quality. A secondary benefit of this signalpreparation is the ability to apply a consistent timing and sync frequencyto the projector, avoiding the glitch that occurs when the projector reactsto a signal change and must resync to the input. This provides a morestable display and requires only a single projector setup.

There is often an additional requirement that the integrator needs toaddress when designing a control room. For ease of integration, the roomdesigner will likely need to identify non-invasive solutions-signalprocessing, routing, and display systems compatible with existing computerhardware and software. When RGB's ComputerWall processor was selected todisplay computer images across a 2W5 configuration of rear screenprojectors from Electrohome Projection Systems for the telecommunicationscenter of the Provincial Telecommunications Authority (PTA) of China'sHubei Province, it was after an X-Wall system was considered and rejected.The X-Wall system is based upon the X-Windows system, a graphical windowingenvironment that runs under any OS. The main function of X-Windows is toallow users to run applications on other computers in the network and viewthe output on their own screen. It uses client-server technology requiringdedicated hardware and special X-Windows programming to manage the displaysharing, and it imposes processing and disk space requirements on the hostsystem. In the PTA application, the customer believed it too costly andcomplex a job to create the new software needed for such an approach. As astand-alone box solution, the ComputerWall provided a simple,cost-effective alternative. The PTA inserted the processor between theirexisting computers and projectors and achieved a display wall. This conceptof a non-invasive solution is illustrated opposite figure. The output offour computers are connected to the ComputerWall. The operator controlswhich computer is selected to be split and displayed across the 2W2configuration of projectors. In this example, Computer 1 has been selected.Alternatively, all four computers can be displayed at once with each beingrouted directly to one of the four screens.