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Fig. 1. Eurotherm 808


Display technology has come a long way from its roots at the start of the digital age and the production of LCD screens for watches and calculators.

Today, affordable industrial monitors with screen sizes in excess of 40 inches can be found in manufacturing facilities, and typical examples are used for shop-floor overview screens, production output displays and to provide quality/HSE information.

The technology continues to expand, and for home-use purposes, the latest 3-D televisions are starting to be produced without the need for uncomfortable glasses so that the viewer is fully immersed in the entertainment experience. New gaming systems such as Kinect (Microsoft Xbox) and the successful Sony Wii console have improved the gamers experience by concentrating on the user interface. Virtual-reality systems are starting to gain favor by high-technology manufacturing companies wanting to safely train operators in emergency health and safety practices within a true disaster scenario rather than just relying on outdated classroom teachings.

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How Does this Impact the Heat-Treatment Industry?

The development of large screens was primarily motivated by an initial requirement to produce screens above 14 inches to replace the existing energy-hungry, bulky CRT screens that were the norm of their day in home use.[1] Today, it is now cost effective to use these display screens within heat-treatment operations to display information (production, sales) in a timely manner.

LCD technology, having started with small monochrome screens (calculators and watches) and progressed to larger displays, has now filtered back down creating crisper displays on smaller devices such as cell phones and full-color Smartphones/PDAs. This technology is now available for use in instrument displays that are used in the heat-treatment industry. This article will further outline the technology trends and changes in product designs.

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Fig. 3. Instrument displaying simple bar graph

The Past

Over the past 20 years, industrial instruments on furnace equipment have slowly moved from 1/2DIN-sized instruments (e.g., Barber Colman 560/570) to smaller 1/4DIN, 1/8DIN (e.g., Eurotherm 808 – Fig. 1) and even 1/16DIN instruments (Fig. 2).

Technology improvements in component design have enabled many components to be shrunk in size. Screen technology has also improved, enabling greater detail to be shown in a smaller package.

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Fig. 4. Auto-scrolling text

The Present

The 1/4DIN is a typical instrument size on a furnace in the U.S., and 1/16DIN instruments are starting to be used on laboratory furnaces and small ovens. Typical LCD screen technologies used in today’s instruments are FSTN and DSTN (see sidebar).

Due to the improvements in screen technology, 1/4DIN instruments not only communicate the PV, SP and output %, but can display simple bar graphs (Fig. 3) as a quick-look operator aid to see if the process is in control.

Also, 1/16DIN instruments have started to incorporate features to make the display easier to understand. Auto-scrolling text (Fig. 4) that expands an alarm code and gives real-world information is typical of these enhancements.

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Fig. 5. The new nanodacTM has a 3.5-inch TFT color display (320 pixels wide x 240 pixels high)

The Future

The parallels between DIN sizes and products such as the iPhone and, more recently, the iPod nano serve to show what is possible to communicate via a small screen and give us a potential view into the future. In fact, if you look at an iPhone screen and a 1/4DIN controller, the screen size is amazingly similar. Eurotherm has recently taken advantage of this and the relatively new cost competitiveness of these screen types and brought out its new 1/4DIN recorder/controller product – the nanodacTM (Fig. 5).

Touchscreen technology is still typically in the 1/2DIN size and above, and many companies use this for paperless video recorders. With the features in the iPod nano (similar size to a 1/16DIN screen) it’s feasible (but speculation) to see these types of screens together with pinch and zoom being available sometime in the future.

For larger-screen systems there are new Immersive Virtual Reality Training Systems from SimSci Esscor (Invensys Operations Management). The EYESIM solution is comprised of a modeling engine, powered by SimSci-Esscor’s DYNSIM®, serviced through the SIM4ME® bridge and coupled with a high-performing virtual-reality engine and a high-quality 3-D modeling/scanning toolset, which is then displayed on a large LCD screen (40 inches and above).

The operator interacts with the system utilizing joystick-type controls that are found on most major gaming devices and wears 3-D glasses. This enables the operator to get a good visual as well as hands-on operation of a process. The benefits are seen as a more realistic environment for trainees with opportunity for extended practice sessions not normally permitted due to production constraints, improvements in health and safety compliance by practice in hazardous situations, and the ability to capture best practices across operators and reduce the up-front training costs associated with new recruits or cross-training. IH

For more information: Peter Sherwin, business development manager – heat treatment, Invensys Eurotherm, 44621 Guilford Drive, Suite 100, Ashburn VA, 20147; tel: 703-724-7300; fax: 703-724-7301; e-mail: Peter.sherwin@invensys.com; web: http://iom.invensys.com/eurotherm

SIDEBAR: Different Categories of LCD Technology[4]

“A Liquid Crystal Display (LCD) is a thin, flat electronic visual display that uses the light modulating properties of liquid crystals (LCs). LCs do not emit light directly.”[2] Different types of display are described below. The ability of the liquid crystals to twist and untwist at varying degrees allows levels of light to pass through.

TN – Twisted nematic LCD has a layer of liquid crystal material supported by two glass plates. It has single coloration with black characters on gray background, which is the least expensive of the LCD technologies with the lowest quality, particularly in viewing angle.

STN – Super twisted nematic LCD has a higher twist angle than TN, which enables a greater contrast.

FSTN – Film-compensated super twisted nematic displays enable higher contrast and better viewing angles.

DSTN – Double-layer super twisted nematic display can improve the color shifting that can occur with conventional super twisted displays.

TFT – Thin film transistor has the best resolution of all the flat-panel techniques, but it is also the most expensive. Each pixel is controlled by one to four transistors.