What is High-Performance HMI?

Hello and welcome to Take Five with Automation World. I’m David Greenfield, Director of Content, and in this episode we’ll explore the split over user preference for high-performance HMI displays and the more colorful HMI displays that started becoming more prevalent in the early 2000s.

Though the term high-performance HMI sounds like a very advanced and possibly complex type of HMI display, it’s actually quite the opposite. High-performance HMIs, in contrast to more standard, modern HMI displays, are not very colorful. For example, each device or piece of equipment won’t be represented with different colors, and you won’t see pipes actively filling with blue or green fluid, or flames underneath a tank indicating an active boiler operation. Instead, a high-performance HMI will be primarily gray with just the devices or systems requiring attention highlighted in any kind of attention-getting color.

Proponents of high-performance HMIs say the gray-scale screens with minimal color enable better situational awareness for operators by better directing their response to high priority problems.

Despite this, there are many industry professionals who prefer the more highly graphical type of HMI displays. They like the realism provided by the colorful graphics, and some equipment manufacturers say the more advanced and colorful HMIs allow OEMs to encode help for operators inside the HMIs.

Clark Kromenaker, product manager at Omron Automation, says machine builders have been quick to pick up on the expanded capabilities of these colorful HMIs to embed things like operator instructions or machine fault diagnostic videos. He says: a touch of realism on faceplates, for example, can also enhance the safety of interacting with a machine. For example, the operator can adjust the HMI-displayed template of an array of smart sensors, just as if he had the control cabinet door open and was adjusting the physical device itself. Such HMI faceplates also exist for recipes and alarms.

Possibly the biggest reason for choosing a high-performance HMI are the data that show the potential downsides of the more colorful HMI displays. Investigative bodies such as the U.S. Chemical Safety and Hazard Investigation Board, have identified the more colorful HMIs as causal factors in at least three refinery explosions. And a study commissioned by the U.S. Navy found that users of more simple HMIs outperformed users of the video game-style HMIs by 70%—despite an overwhelming preference among the users for the video game look.

An example of operators who have come to prefer the low-graphic version of high-performance HMIs are the operators at the Pima County Regional Wastewater Reclamation Department.

Pima County’s engineering staff said the previous, more colorful HMI design had been overwhelming the operators with too much data and nuisance alarms. Using Aveva’s InTouch software, Pima County’s engineers were able to avoid these problems by applying the principles of situational awareness to the HMI’s window structure, color scheme, and alarm hierarchy. This enhanced the staff’s ability to perceive and understand what’s happening in the facility and focus their attention on what needs to be done. As a result, key alarms no longer get lumped in with the nuisance alarms, enabling operators to address them right away…before they have time to develop into serious problems.

John Krajewski, vice president of product management at Aveva, says: Color can be very effective in catching the attention of an operator, but overuse greatly diminishes its ability to continue capturing the operator’s attention.

Despite the proven success of high-performance HMIs, the look and feel of consumer applications will likely continue to influence industrial HMIs. Eric Reiner, industrial PC product specialist at Beckhoff Automation, says: Beyond generating a comfort level among users, the use of advanced graphics in HMIs can help improve the user experience and shorten the learning curve for machine operators.

Bottom line: it looks like the debate over HMI styles will continue.

So keep watching this space for new episodes to keep you on top of what’s happening in the world of industrial automation.