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TECH TALK Systems Integration Asia April - May 2015

by Peter van Dijk

Choosing The Right Display Technology An industry commentator recently made a startling comment: Every two days, apparently, we create as much data as we did from the beginning of time until 2003. It’s claimed that over 90 per cent of all data ever created has been created since December 2012. While much of the focus of attention within business over the last few years has been how to make use of this so-called ‘Big Data’ revolution, for control room engineers and facility managers, the problem is far more immediate – how to present that data to operators in a meaningful and practical way. The proliferation of data has been driven by the affordability of IP enabled devices and the networks that connect them together. This is a trend expected to take a sharp upward swing in the near future as the Internet of Things (IoT) revolution really gets underway. And it’s a trend that’s pretty much universal, from traffic control, to factories, CCTV, financial institutions and facilities management. There is more data converging on the control room than ever, and so developing strategies for operators to deal with this tsunami of information is a pressing problem. To make sense of the flood of information coming in, operators need primarily to maintain situational awareness – the ability to see the big picture – but without losing the ability to drill down to individual data streams as necessary. In times past, many control room display systems were based on a schematic arrangement, with screens dedicated to particular information feeds in a rigidly structured, hierarchical way. In today’s world, this is no longer a practical solution. The generally accepted modern approach is to use a single display – usually known as a displaywall or videowall – as a flexible workstation, allowing operators to structure and present data in a much more versatile way that can easily adapt to changing needs and situations. But this in itself

Example of a control centre using DLP Technology

presents a whole new range of problems for the systems integrator. The proliferation of data sources has, in its wake, created a need for control rooms suites where perhaps none existed before. One example might be a local authority that has installed or enlarged its CCTV network using IP cameras. So a major challenge facing many SI’s today is how to physically create a display solution within a space – or a budget – that often was not conceived for that purpose. Thankfully, the two main professional display technologies today, DLP rear projection and LCD, provide some flexibility. However the two technologies are not interchangeable and need to be selected with care if an expensive mistake is to be avoided.

Rear Projection DLP Displays

Rear projection DLP displays based around the Texas Instruments’ DMD chip have been the mainstay of control rooms for many years. Originally lit by mercury lamps, today’s devices use ultra-reliable LED light sources which can last for many years – in the case of Mitsubishi Electric, over a decade of continuous use. However the real reason

for the popularity of rear projection DLP cubes is not just their longevity but the characteristics of the DMD chip which make it eminently suitable for control room applications. As many readers will know, the DMD chip consists of thousands of individuallycontrolled microscopic mirrors which reflect light from a light source onto a rear projection screen. Changing the angle of the mirrors effectively turns an individual pixel on or off. The key feature of this technology is that the light controlling element is not light transmissive – light doesn’t shine through it, but is reflected off it. Unlike LCD projection, very little energy is retained within the DMD chip itself, so theoretically there is no limit to the amount of light energy it can switch without any ill-effects due to heating. In practice, this means that unlike other display technologies, an individual pixel can be run continuously at maximum brightness for years – decades in fact – without any danger of screen burn or image sticking. This makes DLP absolutely ideal for control room displays, where a static image such as a network diagram or SCADA schematic needs to be displayed for very