The contenders – LCD, RPC and LED
Only Tiled LCD, RPC (Rear Projection Cube) and LED (Direct View LED) are considered to be viable technologies for control rooms in critical infrastructure environments. These include utilities, traffic/transportation agencies, and security and surveillance centers, where having accurate, real-time data can mean the difference between life and death. Each video wall technology has its own strengths and weaknesses, so how do you determine which one is right for you?
The purchasing decision should be driven by the particular requirements of the application. That means resisting the temptation of a special sales price, shiny new housing or initial brightness. The most important factors focus on image quality, reliability and other aspects that help you choose an option that performs consistently at optimum levels for the long term.
We believe that there are five key questions to consider when choosing a video wall for your 24/7 operation. We’ve rated these criteria with respect to the various video wall technologies on the market today: LCD, RPC and LED, indicating their suitability to critical infrastructure environments as follows:
GREEN – Optimal
YELLOW – Satisfactory
RED – Not Recommended
1. Image Quality: What is the level of color, brightness and contrast consistency over time?
Color and brightness are of vital importance in control rooms and are critical factors in comparing displays. While every video wall technology provides plenty of brightness for control room use, the real challenge lies in maintaining a constant brightness over the entire wall, over time.
Things to consider: Are the colors and brightness consistent across the wall? Do you need manual intervention to keep the wall balanced in respect to color and brightness? Will the display units still be equalized (internally consistent) five years from now? Or, even more fundamentally: is it even possible to balance these discrete image generators across an entire wall?
Moving ahead slightly, the fact that Barco’s new RGB laser video walls for 24/7 control rooms deliver the best possible color gamut and are the brightest displays make them the most attractive option for critical infrastructure environments.
2. Ergonomics: What is the viewing distance for control room operators?
A display wall installed in a control room should be ergonomically friendly for the control room operators and supervisors. It is a well-known fact that the display wall should be designed for operator legibility − i.e., can he/she read the fonts?
Legibility is a function of the right combination of the desired pixel pitch plus the aggregate resolution required to display all applications across the wall. Users should also consider the screen viewing angle that enables the operator to maintain a consistent view of the display wall with limited [little or no] brightness drop-off. Proper screen selection and positioning the operator in front of the video wall will produce the most positive result.
3. Reliability and Serviceability: What are the expected long-term reliability and service needs?
Control rooms are built to provide situational awareness in order to facilitate fast and accurate decision-making, so uptime is of paramount importance. Failure of the video wall could lead not only to crises, but devastating financial and company image problems.
These factors are critical in developing the requirements for a 24/7 environment:
• Designed for 24/7 usage
• Redundancy and/or high availability
• Modular design for fast and easy servicing
• Spare parts and service availability
4. Longevity: What is the lifespan and upgradeability of the video wall?
There is an inverse relationship between advances in video wall technology and the typical lifespan of the actual control room facility, i.e., video wall technology evolves much faster than the building housing the control room deteriorates. As a result of this dilemma, investment protection is often overlooked when evaluating the various video wall options.
In most cases, large screen visualization solutions have an average lifespan of eight years, but with the latest laser illuminated models, can extend to more than 11 years. But beyond the estimated lifespan, you should also consider the following factors:
• Designed for longevity in a 24/7 operation
• Supplier EOL (End-Of-Life) and EOS (End-Of-Service) policies
• Maintenance contract offerings and commitments
• Form, Fit, Function technology upgrade offerings
• Investment protection
Note: It is also very wise to invest in a display wall that has the ability to be upgraded over time to avoid costly re-construction work.
5. Total Cost-Of-Ownership (TCO): What are the total costs incurred over the control center’s lifetime?