The major developments in industry - from the Internet of Things (IoT) and greater individualization to the closer linking of all process steps - do not stop at the components at the interface between man and machine. Digitalization not only provides deeper insights into the behaviour of individual components, but can also deliver added value in all aspects of machine operation.

Probes that are equipped with sensor technology and therefore act as a measuring device play an important role here. After all, companies can use the sensors to obtain valuable information such as the degree of soiling, the outside temperature and the frequency of operation. In addition to measuring the current level of functionality, such a push button also provides relevant data, particularly in the area of predictive maintenance.

This is made possible by a new generation of push-buttons that no longer have much in common with their mechanical counterparts.

Predictive maintenance

While these require mechanical pressure, electronic touch sensors are depressurized by touch. The button builds up an electric field and continuously measures the capacitance between the surface and the sensor environment. If a hand or finger, which as such has a relatively high conductivity, approaches, the capacitance increases and the switching process is carried out. Even a glove does not interfere with the functionality.

One specific application of such a button, which supplies additional data to the machine control system in the field of predictive maintenance, is the 'safeCAP' two-hand control from Captron. It is particularly suitable for applications in production automation where employees are exposed to a high risk of injury, for example when handling presses and punches. For safety reasons, these only start their work when two switches are actuated simultaneously. It is therefore essential that both switches function perfectly to ensure the safety of workers. A new-generation intelligent push-button also reports minor faults automatically, which reduces downtime.

Borrowing from the smartphone

At the same time, such buttons also enable operating patterns that were previously only known from smartphones and are now also proving their worth in an industrial environment. For example, a different function can be triggered depending on whether the user presses the button once or twice in quick succession or holds it down for a long time. Modern push-buttons can also be programmed for special sensitivities.

Each sensor is a measuring device and collects data such as degree of soiling, functionality or outside temperature.

© Captron

In view of these characteristics, a wide range of industries can benefit from the possibilities of intelligent push-buttons. In the traffic and transportation sector, for example, several aspects such as dirt and water detection, the transmission of various communication protocols or even switching through layers of ice are relevant. The same applies to the use of commercial and special vehicles as well as public and private buildings. Robust solutions that function reliably even when heavily soiled are often required here.

In the areas of industrial automation, plant and machinery as well as food and beverages, modern pushbuttons work as intelligent IoT devices. There are already corresponding projects in the logistics sector, e-commerce and warehouse management, where the pushbutton not only provides operating and status information to downstream IT systems, but also delivers operating instructions and instructions via its own small mini display.

Integrated into the ERP system

The potential of an intelligent pushbutton can be fully exploited if it is seamlessly integrated into downstream production solutions, such as ERP or MES systems. With RS232, I/O-Link, CAN bus, Profinet and TCP/IP, the corresponding interfaces are available.

With the help of machine learning, sensors connected in series will share learned data with each other in the medium term. This will make calibration to new environmental conditions faster and more efficient. It is also possible that capacitive sensors will be able to be fed with external data such as weather forecasts in the future. It is conceivable, for example, that buttons will automatically adjust their sensitivity when a cold weather front approaches so that users can operate them without any problems even when wearing gloves.

Author:
Philip Bellm is Managing Director of Captron Electronic in Olching.