IN CONTROL
May 1, 1999 12:00 PM, Amy Silverman
Imagine the control room of almost any industrial enterprise-telecommunications, power management, traffic control, emergency management. Each of these critical nerve centers must handle large amounts of constantly changing visual data. The information arrives at the control room in a number ofdifferent forms-video from a satellite downlink, sensor data gathered from remote monitoring equipment or systems analysis applications running on networked workstations. Although the data and the process being controlled will be different, there are a few core requirements 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 NTSC composite 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 about those VGA, SVGA, XGA and SXGA computer screens you need to switch in to the display? Consideration must be given to every variety of visual information used in the command center. Analog vs. digital, color space issues like NTSC vs. RGB, interlace vs. non-interlace, resolution, and different scan and frame rates all must be addressed in the display system configuration planning.
Moreover, the typical command center is staffed by numerous operations personnel. To create an effective communications environment, information on individual workstations and video monitors must be, at times, made readily available to all or part of the command center staff. Instead of crowding around a small screen intended for personal viewing, decision-makers can do their jobs more effectively if the information is instead routed to a large screen.
A third requirement derives from the first two-the need for individual operators to monitor multiple sources of visual data. Bombarded by a variety of video and computer sources, the operator must keep track of all information. If the data is combined onto one large screen or multi-screen display he will have a much easier time tracking it. Additionally, a large screen solves the second requirement for sharing that information with the rest of the staff.
Most control rooms also use a high ambient light environment mostly because of the need to read printed materials. Although it is an attractive goal, most businesses have not quite made the leap to a paperless office. There is also a general concern for the alertness of the control room operator. A reasonable amount of ambient light is usually desirable to maintain an attentive command staff. These lighting conditions can prove challenging for projection and display equipment. The brightness of these devices must be enough to combat the ambient light conditions and provide sufficient lumens for a legible display.
Lastly, the majority of control rooms are managing processes without down time. They must operate 24 hours a day, seven days a week. The water never stops flowing, and the power never goes off. Just as the process has its backups and failsafe supports, so must the control room. To the systems contractor designing the installation, this can mean planning for redundant systems and a store of backup components to replace a downed system quickly.
All of these requirements, combined with technological advances in managing video images, have meant the evolution to a more high-tech approach for control room information management. You might have walked into an electric power command center 10 years ago and seen static displays with scale diagrams of the power system being hand marked with tape and pushpins to indicate downed lines and other system problems. Fortunately, improvements in handling and displaying computer and video data have changed the face of command centers. For companies looking to upgrade control facilities or add new ones, there exists a large selection of image processing and display equipment from which to build a sophisticated visual communications system.
RGB Spectrum, for example, manufactures a number of video processing devices and subsystems used in control rooms and other A-V applications. The following examples illustrate how leading-edge processing and display equipment can be used to fulfill the core requirements of the modern command center.
The 1996 Olympics When the Georgia Power Company was named the official power source for the 1996 Olympic Games, it needed a command center to monitor the flow of power to all Olympic venues and track everything from weather to traffic flow to media reports. To manage this information and support its pledge to keep the lights on, Georgia Power and its systems contractor, Insight Research, designed and constructed a control facility with two completely redundant systems. Although the games have left Atlanta, the center is in use today as a storm watch facility.
The cornerstone of the command center is the high-resolution, multi-screen display wall, constructed with 67 inch (1.7 m) rear screen projectors from Barco and a ComputerWall processor from RGB Spectrum. The display wall allows the command center staff to view dozens of different computer and video signals at high resolution on a large screen for greatly enhanced visibility. With the ComputerWall, one signal can be magnified and split over all four projectors, maximizing the image visibility for the entire room. Supporting the wall is a network of switching and scan doubling equipment, allowing a large number of computers and video sources to be routed to the display wall. All of the video sources are first line doubled to generate a flow of enhanced-resolution component RGB signals. These signals can then be sent through the RGB switching equipment along with the various computer sources and selectively fed to the ComputerWall for display on the 2x2 wall of rear screen projectors.
Traffic management In the Los Angeles Automated Traffic Surveillance and Control Center (ATSAC), the application calls for mixing video and computer inputs in their native formats on a single display, as opposed to line doublers. The ATSAC operations center was built to manage traffic in the city limits and on the Smart Corridor of the Santa Monica Freeway. By using a variety of electronic surveillance and detection systems, including video cameras, traffic engineers can pinpoint and solve problems more quickly and keep traffic flowing.
American Video Communications, Los Alamitos, CA, designed and installed this control room. The facility uses seven data grade CRT projectors on 67 inch (1.7 m) rear screens. With the addition of RGB's SuperView windowing systems, the center can show live video feeds, computer-generated traffic grids and maps all on each large screen display. As events warrant, each source can be sized from a small window up to full screen for closer inspection. Being able to show multiple inputs on a single display makes the individual operator's job easier. Instead of monitoring several screens, thereby increasing the likelihood of missing potentially critical events, vital information is kept on one screen.
The technology used in these control rooms continues to evolve, and systems integrators need to keep educating themselves on these advancements. Improvements in projector technology have delivered a slew of new products with expanded specifications and functions to the visual communications customer. The traditional display choice, a CRT projector or monitor, has become increasingly challenged by such new discrete pixel technologies as DLP and LCD. These devices offer the benefit of higher output brightness and a smaller, lighter form factor.
These discrete pixel projectors, however, lack the flexibility of CRT technology in accepting a wide variety of RGB signals. They have a native resolution and limited acceptance ranges for horizontal scan rate and vertical 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 be managed, but it will be scaled by the projector's internal electronics. Most newer models have integrated decoding and scaling electronics, but the quality and precision of the translation varies among projectors and from input to input. Thus, it is often necessary to consider pre-processing signals prior to the projector so that they conform to the native resolution 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 quality digital video scalars, with the flexibility of taking video and scaling it up to the native resolution of the target display device. Previous generations of doublers use one of two approaches. One replicates each line of video, giving an output that is free of motion artifacts but has low vertical resolution. The other approach merges two interlaced fields to provide a frame, preserving full vertical resolution but generating a severe feathering effect on moving objects. Digital video scalars apply motion detection and high-order interpolation algorithms to preserve full vertical resolution with minimal motion artifacts. The precise scaling of the output signal means it can be tailored to the requirements of the display. Video can be doubled, tripled, quadrupled or set to any line count and frame rate desired.
To match computer signals to the fixed resolution of DLP and LCD projectors, there are RGB up and down converters. Once again, this pre-processing avoids activating the projectors' electronics, consequently yielding higher image quality. A secondary benefit of this signal preparation is the ability to apply a consistent timing and sync frequency to the projector, avoiding the glitch that occurs when the projector reacts to a signal change and must resync to the input. This provides a more stable display and requires only a single projector setup.
There is often an additional requirement that the integrator needs to address when designing a control room. For ease of integration, the room designer will likely need to identify non-invasive solutions-signal processing, routing, and display systems compatible with existing computer hardware and software. When RGB's ComputerWall processor was selected to display computer images across a 2W5 configuration of rear screen projectors from Electrohome Projection Systems for the telecommunications center of the Provincial Telecommunications Authority (PTA) of China's Hubei 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 windowing environment that runs under any OS. The main function of X-Windows is to allow users to run applications on other computers in the network and view the output on their own screen. It uses client-server technology requiring dedicated hardware and special X-Windows programming to manage the display sharing, and it imposes processing and disk space requirements on the host system. In the PTA application, the customer believed it too costly and complex a job to create the new software needed for such an approach. As a stand-alone box solution, the ComputerWall provided a simple, cost-effective alternative. The PTA inserted the processor between their existing computers and projectors and achieved a display wall. This concept of a non-invasive solution is illustrated opposite figure. The output of four computers are connected to the ComputerWall. The operator controls which computer is selected to be split and displayed across the 2W2 configuration of projectors. In this example, Computer 1 has been selected. Alternatively, all four computers can be displayed at once with each being routed directly to one of the four screens.
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