Smart phones have become synonymous with user-friendly, intuitive devices. Many are the stories of children who grab a cell phone for the first time and quickly learn how to navigate and use the device, often to the chagrin of their parents.
Many of the qualities that make the cell phone interface so intuitive are enabled by the hardware of the human-machine interface (HMI) display itself. At long last, many of those same hardware features are finding their way to the operator interfaces that are the front end of factory and process equipment. This makes the HMI more akin to the devices we use and carry every day, and it adds to the general user-friendliness of the interface.
Multi-touch capacitive technology
We are accustomed to using multiple fingers for many actions on our personal screens, such as pinch to zoom, two-fingered scrolling and swiping actions. These features are enabled by multi-touch technology.
One additional major improvement that multi-touch brings to industrial HMIs is having to use a second finger on a designated area of a screen that enables the HMI’s other buttons. This two-hand requirement reduces false or accidental operations on the screen. This could be from accidental bumping, insects hitting the screen, in the case of outdoor installations, or visiting executives not realizing the panel is a touchscreen and activating buttons on the screen while pointing at it—a true story for another time.
Gesture support, both touch and touchless
Swiping, scrolling and pinch-to-zoom actions, which are mainstays of consumer devices, are enabled by the aforementioned multi-touch technology. These same actions can be very useful for HMI screens for zooming in or out of graphics of an assembly line to analyze where a fault or error originates, scrolling over a single large graphic of a factory line instead of having it split into several separate pages or to zoom in and out of a document or operating manual that gets pulled up as part of operations.
Similarly, touchless gesture support is enabled by cameras on the front of the display, and it gives some ability to activate the screen without physical contact. For areas with contamination concerns, such as cleanroom environments, this can be a very important technology that helps avoid both the cost and wear of cleaning the panel frequently.
Edge-to-edge displays
As display technology improves, one trend for HMIs has mirrored consumer devices: edge-to-edge displays. By minimizing or eliminating the dead space around the display, they maximize the available screen area. This allows a smaller display to have the same functional area as a larger one or the same size bezel now offers more display area. Both scenarios allow the user to have more content or better representations on the screen.
Haptic feedback
Providing a physical, tactile feedback to the operator’s touch inputs closes a sensory disconnect between the operator and the response from the HMI screen. A small bump or vibration can indicate that a virtual button is activated, very helpful in general but also becoming more critical in noisy environments where an audible click would not be an effective feedback mechanism. As haptic technology evolves, expect the ability for the user to feel and differentiate virtual buttons, switches and valves and even distinguish different textures, improving the tactile information back to the user.
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High-performance processors and graphics
Following Moore’s Law for processing power and speed, the latest generations of HMI processors are orders of magnitude faster and sharper than those of a few years ago. For graphics, this means a smooth-running HMI, free of screen button activation delays and slow graphic regeneration.
Beyond just the benefit of speedy graphics and communications, however, many HMI panels have enough spare processing power that they can be used as edge devices themselves. Running analytics or machine learning tasks directly on the panel is now a reality. Supervisory control and data acquisition (SCADA), predictive-maintenance (PdM) tasks and quality alerts can run on the same panel as the HMI program, saving the cost of a separate processor to run these tasks, or saving the communication traffic to, and processing power of, the main controller from having to complete these functions.
Improved environmental and durability standards
Of course, just as our cell phones have evolved into tough, waterproof devices that can survive an accidental dip in the pool or drop on the sidewalk, so have operator panels become ruggedized to survive vibration or water/dust ingress. Washdown models for food and beverage industries are completely sealed and waterproof, adding to the cost savings of having to build custom waterproof enclosures for the HMI.
Just as consumer products have driven advances in the automation industry with relation to communications, such as standard Ethernet fieldbuses, Wi-Fi and Bluetooth, and increased processing power in standard PC-based architectures in industrial controllers, so has the operator interface benefitted from consumer cell phone and tablet interfaces.
Not only is the benefit operational and functional, but as others have mentioned before, adoption of consumer-driven technology into the automation industry suppresses cost while improving performance and accessibility. And who doesn’t want that?
