Individual adaptation to the respective process and its environment plays a decisive role in the project planning of modern HMIs. Not only on the device side, but also in the graphic design of user interfaces and in the mobile operating concept of systems and machines.

Certain industrial HMI system designs are already state of the art today. For example, the front end of panel PCs with a flat embedded glass surface is now just as common a design as the hygiene-compliant construction of surfaces and housings. Widescreen displays with their variety of screen formats also cover the different requirements. Last but not least, analog resistive touch and protected capacitive touch meet all requirements for single and multi-touch operation. However, there are also new approaches in the design of HMIs. The following explanations outline some aspects of current topics that Schubert System Elektronik implements in the user-specific computer systems of the 'Prime Cube' series.

Design of the HMI interfaces

Various applications can be flexibly integrated into individual user interfaces using widescreen and multitouch. On the one hand, these technologies open up new possibilities in the design of graphical user interfaces (GUI) and thus support graphical configurations for the visualization of processes. On the other hand, interactive operating scenarios for convenient HMI menu navigation can now be implemented in combination with gesture-based control:

Operating a CNC machine: The GUI framework enables the HMI interface to be customized with a wide variety of elements.

© Schubert System Electronics

for example, navigating within process screens, changing data and values, enlarging characteristic curves and graphs. The user should be optimally supported in being able to clearly monitor, intuitively operate and logically control the respective processes.

For the development of user interfaces, it is now possible to rely on standard visualization libraries that enable cross-platform, portable GUI programming. In this way, users not only benefit from freely positionable windows, they can also define their own objects that represent the user interface elements exactly.

The flexibility of GUI design is illustrated by an application from the machine tool sector: CNC control panels today are usually still classically designed as a 4:3 visualization with an additional membrane keyboard. Graphic areas could previously only be implemented using overlapping or frequently changing windows, depending on the size and required area. With widescreen and multi-touch, the functionalities that were previously covered by direct keys can now be integrated into the display as touch functions. And secondly, the touchscreen can be divided into different areas (arrays) in the modern, horizontally expanded 16:9 display format, which document "everything at a glance" for the user: The NC interface can be adopted 1:1 directly and without any adjustment effort. At the same time, additional touch fields for customer-specific applications, such as file manager, database, tool management or a specific soft keyboard, can now be inserted directly to the right and/or left.

The GUI framework developed by Schubert System Elektronik specifically for the individual design of the Qt-based user interface now enables the control of an external PTC camera installed in the machine room with zoom and movement functions via gesture control. Further application-specific plug-ins integrate TCU data communication, PDF and VNC functionality. Internet-based connection with smart devices via an implemented web browser is also supported so that all functionalities of an automation process - in addition to the centrally installed IPC - can also be addressed by mobile IT end devices.

Today, automation processes in industrial environments are usually still operated and monitored via central control systems. However, there is an increasing demand from the technical sector to be able to access all functionalities on mobile devices. Modern, internet-based HMIs must therefore fully support both stationary and mobile solutions - both will have an equal right to exist in the future.

Interaction with smart devices

However, smartphones and tablets are more likely to open up sub-areas as practicable HMI solutions for such applications - for example, as docking stations in niche applications such as recipe management, setting up machines and systems and the diagnosis and maintenance of control or automation systems. This is because these devices provide access to the latest information: at any time, in any place, on any status.

This means that future Internet-based HMI solutions must be able to run in conjunction with mobile devices regardless of hardware and operating system. This is where HTML5 comes into focus, because this 'Internet core language' is an open standard and platform-independent. In addition, there are now countless frameworks available with which HMIs can be operated anywhere using an appropriate web browser. With HTML5, functionally sophisticated and graphically attractive operating and display functions - also in conjunction with multi-touch and gesture control - can be implemented in a web-compliant manner so that they can be accessed from mobile smartphones/tablets via the Internet. In this way, all intervention options and process images are displayed fully automatically on the end device.

Large displays on trend

Another trend: demand from industry is increasingly targeting larger screen formats. Driven by multi-touch functionality, there has also been a switch to widescreen. This is also driving the trend towards higher resolutions. At 3840 x 2160 pixels, the new Ultra HD technology with 4K picture resolution offers four times the resolution of Full HD - this means over 8 million pixels with 4K compared to 2 million screen pixels with Full HD. With a 4K resolution, the images look even sharper and more realistic. With a 28-inch UHD/4K display, Schubert System Elektronik is responding to the increased market requirements.

The industry often requires classic operating elements in addition to the touch function. The solution: an add-on PC with a multi-touch display and button modules.

© Schubert System Electronics

A problem that larger displays have often brought with them to date: The expensive front frame - usually milled from solid material. A new design consists of various individual profiles, each of which is identical in its side or top and bottom parts and serves as a flexible plug-in system for small to large display formats. The benefit lies in the modular design and the low-cost production.

There are also new technical processes for the front-end design of the displays, which ensure an improved, visually clear presentation. Until now, there has been a small air gap between the touchscreen and the actual display, which is mounted directly behind it, which can cause unwanted reflections, condensation effects or parallax errors. This greatly impairs the readability of the displays, especially in direct sunlight. The solution: With 'optical bonding', the display and touchscreen are bonded together directly using a highly transparent adhesive technology.

This process securely joins the two components together without air inclusions. This prevents internal reflections and fogging of the screen - dirt cannot penetrate. This makes the display unit much more robust against mechanical influences.
As machines are becoming ever larger in terms of complete processing, the distance between the HMI station and the PC is also increasing.

Remote monitor link

Decentralized structures, in which the host computer and the operating unit form a remote system network as a passive monitor solution, offer great flexibility in the solution of HMI topologies. The type of link depends on both the distance to be bridged and the required functionality of the application.

The 'Prime Cube' series provides appropriate methods for setting down the operating unit. Direct signal transmission is suitable for distances of up to approx. 10 m. Embedded clients can be used to implement networks over distances of up to 100 m. To cover complex system configurations, the digital transmission technology Remote-Link offers particular advantages: Independence from the operating system, no need for external transmitter/receiver modules, all signals (video+touch+USB) as well as the PoH supply (Power over HDBaseT) are transmitted together via a single CAT6 Ethernet cable between the display and host. It is also possible to bridge large distances - for example, up to 140 m with Full HD resolution or 100 m with UHD resolution, which enables optimum positioning of the host PC and panel, especially for extensive systems. Integration is possible with box PCs from the 'Prime Cube' series as well as via PCI or PCIe in third-party products.

Extended inputs via key module

New technologies enable the integration of additional operating elements into a multi-touch system - with a continuous glass surface without protruding contours in protection class IP65. The frequently required function keys outside the active touch array are embedded in the front glass as short-stroke keys for fast operation with haptic feedback. They can be individually designed in terms of symbols and lettering and can be controlled by LED depending on the function. The direct serial connection of these additional functions to the HMI or operating system ensures a fast response without having to route the signals via the controller. By providing all common fieldbus interfaces, such as CAN bus, Profibus, Profinet and Ethercat, a universally configurable connection to the control system can be implemented.

Software and hardware are crucial

The integral elements of industrial usability include both the technological requirements in the hardware and the necessary standards in the software. The same also applies to industrial systems: Not every trend in IT electronics is emerging as viable, as the focus in industry is on longevity and long-term availability. Only those technologies that prove to be reliable and marketable will find their way into future industrial HMI solutions.

Author:
Bastian Beha is a marketing consultant at Schubert System Elektronik.