Does the interface conform to ergonomic principles? Does your operator interface terminal cause you pain? I'm not referring to mere disappointment and frustration due to its inability to function correctly. I'm referring to genuine, empathetic pain, like any real computer terminal; an HMI will encounter health and safety-related usage issues. When working with HMIs, correct ergonomics are generally not the first thing engineers consider. However, neglecting ergonomic principles leads to increased operating costs, not to mention eye strain, wrist syndrome, and sprains. What is ergonomics? There are many definitions, but essentially it is a rigorous science. Microsoft's Encarta encyclopedia defines ergonomics as: "The science of designing machine products and systems with the aim of maximizing safety, comfort, and efficiency for the people using them." The Board of Certification in Professional at Ergonomics (BCPE) calls it "a range of knowledge about human capabilities, limitations, and characteristics to consider when designing." Regardless of how you define it, ergonomics plays a crucial role in every HMI application, influencing how operators effectively use the product. More importantly, it addresses injuries caused by non-compliance with ergonomic principles. Furthermore, workplace-related ergonomic injuries can be the root cause of costly employee claims and lost work time. Ergonomics varies from place to place. Ergonomic challenges can be presented to HMI products in various ways, including, but not limited to, musculoskeletal and visual difficulties. Bill Martin, PanelView Plus 700/1500 Product Manager at Rockwell Automation, said, “For HMI devices, there are two ergonomic considerations: glare-resistant screens and easy-to-use buttons. Components like glare-resistant covers reduce eye strain and are easy to remove or replace when dusty or dirty. Operators using glare-resistant covers not only protect their eyesight but also benefit from their convenience and ease of maintenance.” He continued, “Many operators use touchscreens because they are easier to use; however, those who prefer buttons do so because they can hear and feel feedback when pressing them, reducing mental and physical stress. Operators don't need to repeatedly press buttons and worry about whether they've made contact.” Dave Kaley, Mobile at Rockwell Automation, said… A LabVIEW product manager observed handheld HMIs and commented: "Because the terminal is in your hand, it's important that it's easy to hold and operate. For example, a portable terminal must be comfortable and ergonomically friendly for both left- and right-handed users." Kaley suggested: "The hand holding the terminal should be in a natural, relaxed state, not in an awkward, bent, or uncomfortable position that could lead to wrist sprains." Norma Dorst, LabVIEW Platform Manager at National Instruments, pointed out: "An often overlooked area of ​​ergonomics is how alarms are set up. This is a part of ergonomics and deserves sufficient attention. The same alarm cannot be used for every malfunction. The sound must alert the operator, but not to the point of interfering with their reaction time. Many HMIs provide too many pulse and flashing signals, which is not ergonomically designed." The Reversible Tip When selecting and designing any HMI system, consider the following ergonomic factors: ■ When deciding on a selection, evaluate the ergonomic characteristics and functionality of the chosen HMI product. Is the screen resistant to strong light? Is it easy to operate? Is it ergonomically friendly? ■ When using HMI products, their functionality is similar to that of any computer, and the same warnings and limitations should be examined. Repetitive actions need to be minimized. HMIs are open to any modifications, thus adapting to different needs. ■ When installing any new system, time should be spent understanding the concepts and principles of ergonomics. Ergonomically designed intelligent operation can increase work efficiency and reduce lost work hours, personal injury, and consequently, employee claims.