Human Machine Interfaces - Touch control reinvented

Garz & Fricke Group Human Machine Interface

Wherever people normally come together, distance is the golden rule. This leads to an increased desire for security, even for vending machines that are operated by finger touch: Coffee and drink vending machines in public places and coffee kitchens, pay machines in parking lots and car parks, ticket vending machines in public transportation and at train stations - to name just a few examples. Many people are therefore asking themselves right now how a high level of hygienic and protective conditions can be guaranteed. The use of touch displays, which are easy to clean hygienically, is already an immense advantage compared to mechanical buttons and operating elements. These systems were already difficult to clean before COVID-19. This hygienic advantage can now be increased by eliminating even the last touch on the Human Machine Interface (HMI). The Garz & Fricke Group makes this possible with the new Remote Touch System (RTS).

Touch-sensitive remote control

"Basically, users can operate a device without touching the integrated touch display," explains Sven Liess, Managing Director of application developer e-GITS, which has been part of the Garz & Fricke Group since 2019. Instead of operating vending machines via the integrated touch panel, this is just as well to be done via smartphones. "The bottom line is that we have developed an enhanced touchpad," says Liess.

The innovative software solution can be used in devices with Wi-Fi or mobile phone modules. Via Wi-Fi, the smartphone can directly establish a channel to the vending machine. If a mobile phone connection is used, the Garz & Fricke Cloud works as an intermediary between the vending machine and the smartphone.

Contact is made via QR codes, a kind of two-dimensional barcode. The QR code is applied as a sticker directly on the vending machine or shown on its display. The user scans the code and thus selects the machine to be operated. It is not necessary to install an app on the user's device. Instead, a connection between the machine and the smartphone is established without further interaction.

A so-called WebApp is used for the actual operation of the machine. A special graphical user interface (GUI) opens in the web browser. In the simplest and most universal version, it does not display the surface of the machine, but simply registers touches, like a touchpad, and forwards them directly to the vending machine. "Via this control channel, the inputs are transferred from the smartphone screen to the machine itself", explains Sven Liess, "without having to touch the touch screen of the machine". For this purpose, the user's smartphone displays more or less only a black area in the web browser, the "touch-field" for machine interaction. A small arrow or a hand symbol in the display of the vending machine indicates the user where the pointer is currently located on the device to be operated. Now the user can intuitively control and click on buttons. "The user does not even have to look at his smartphone," explains Sven Liess, "but can concentrate on the screen of the machine. He controls the movement of the pointer intuitively, just like a touchpad on a notebook. Only without cables, but wireless."

For special customer requirements, the specialists of the Garz & Fricke Group have also developed a customizable interface that displays the screen content of the vending machine on the smartphone in a mobile device compatible format. The contents of the HMI are given an equivalent - for example a labeled button - in the web interface on the smartphone. If the user clicks on this button, it corresponds to the print of the equivalent button on the machine. The customer can recognize this by the fact that he can also see on the machine how the button is activated or virtually clicked. This is how the Garz & Fricke Group implements an intuitively usable and self-explanatory remote control that meets the highest demands on physical infection protection.

The remote touch system is technically realized as a software package that can be integrated into current and future developments of Garz & Fricke. The base of the RTS is a minimal web server, which delivers a special web interface to the smartphone. Via this interface, the touch events are registered and forwarded to the vending machine.

Safety first

During the development of the remote touch operation, IT security was a top priority in addition to an optimal user experience and operational reliability. By limiting the number of active connections to only one at a time in combination with unique session keys that are generated for each use, it can be ensured that only the terminal device that is currently logged on controls the machine. In addition, a recognition of the completed operating process ensures that the smartphone that was still active a moment ago is logged off again and the application is released for the next connection.


The Remote Touch System of the Garz & Fricke Group is available from now on. The Garz & Fricke Group also has many years of experience in the replacement of mechanical control blocks with same-fit glass touch HMI modules. The Hamburg-based specialists enable manufacturers to convert mechanical buttons and operating elements to modern touch display controls quickly and easily, even for existing series products.

"Do you have any questions about our news or do you need more information? I look forward to your call or e-mail."

Steven Kluge, Head of Marketing

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