Digitization of Process Systems

Food manufacturers are no longer faced with the question of whether they should digitalise their processes and implement the concepts of Industry 4.0, but instead with which technology partner and how they can smoothly integrate the new approaches. This development is reflected every three years at the Anuga FoodTec trade fair grounds in Cologne, Germany. "In recent years, exhibitors have done a great deal to simplify the use of data obtained via sensors," confirms Roland Thiemann, Director of Anuga FoodTec. Many sensor solutions have been developed that "make it possible to organise the operation of systems and processes even more efficiently", says Thiemann, who has been working in this role for Koelnmesse GmbH since the beginning of 2025.

At the last Anuga FoodTec it became clear: The integration of sensors plays a key role in digitalisation concepts such as Industry 4.0 or Industrial IoT. First and foremost, the aim is to standardise data and its exchange across all system boundaries right through to the cloud. A large proportion of the data is generated with the help of sensors. Their task is to record process variables and transmit them to the higher-level automation systems via interfaces. The basic idea behind cloud computing is to make this data digitally available for system components at all times. The goal is to connect the sensors at field level to the virtual evaluation platform - the cloud. They then, for example, record the temperature or pressure within a process or monitor the vibrations and power consumption of a system as the basis for big data algorithms. This requires a powerful, secure and flexible communication architecture.

However, connectivity to the cloud is associated with a number of challenges in practice. Even today, many sensors are not Ethernet-capable, but instead transmit the measured values to a programmable logic controller (PLC) via analogue current loops (4 to 20 milliamperes). In contrast, the IO-Link communication standard, which is becoming increasingly established in the food industry, is different. It marks the start of digitalisation in the direct machine environment. Experts see this technology, which is independent of fieldbuses, as an essential building block for the smart factory. "In addition to the actual measured value, sensors with IO-Link can also provide valuable diagnostic data. This then helps users to carry out predictive maintenance, thereby extending the service life of their systems," says Alexander Hof, Product Manager at Jumo in Fulda, Germany. The background here is that IO-Link allows these additional values to be accessed by higher-level systems in parallel to the actual measured value. Thanks to its bidirectional communication capability, IO-Link enables detailed diagnostics and real-time feedback from sensors and actuators. This is essential for comprehensive connectivity and precise machine-to-machine (M2M) communication.

The example of Danone, one of the world's leading suppliers of dairy products, shows how the IO-Link standard is a key factor driving automation. The constantly growing consumer demand for plant-based drinks prompted the company to convert one of its largest plants in France to the production of oat drinks. Thierry Pasquet, Director of the Danone plant in Villecomtal-sur-Arros, on the reasons: "80 percent of our customers say they want to switch their diet from animal to plant-based proteins. Naturally, we want to take this into account by increasing our oat drink production capacity. The decision also contributes to Danone's global corporate goals of reducing CO2 emissions and water consumption by 80 percent."

From storage tanks to piping, valve blocks and CIP systems: Everything was switched from milk to oats - within just twelve months. "During this time, all the old systems had to be dismantled in order to rebuild them at other locations," explains Sébastien Peres, who is responsible for automation at the plant. At the same time, the plant components for oat drink production, including the automation technology, were rebuilt step by step. The Peres team, which was supported by integrator Boccard, relied on two technologies from ifm electronic GmbH for digitalisation: AS-interface (AS-i) and IO-Link. AS-i is characterised by the yellow, two-core flat cable, which can be laid over distances of up to 1,000 metres. By adding fibre optic cables, distances of up to 3,000 metres can be covered. Sensors and actuators can be easily connected at any point using AS-i modules. Actuators with higher power requirements can be optionally supplied with supplementary power via an additional 24-volt flat cable, which runs parallel to the data cable and also through the modules. Special field-compatible IO-Link masters bundle the digital signals from the sensors and forward them to the AS-i level. "The IO-Link sensors offer us many more diagnostic options than conventional automation systems, which creates a high level of process transparency," emphasises Peres.

Many of the installed IO-Link sensors transmit additional data alongside the actual measured value. For example, a pressure sensor can also record the temperature at the measuring point. In addition to the current flow rate, flow sensors transmit the pressure, the temperature of the medium and the total flow rate as digital measured values. Another useful feature of IO-Link is the option of saving the parameters of a sensor on the IO-Link master to which the sensor is connected. This makes it very easy to replace the sensor in the event of a defect. Production of the oat-based drinks has now been launched in Villecomtal-sur-Arros. All information can be monitored in real time at a central location. "Thanks to digitalisation, we're informed about all processes and parameters. This allows us to react quickly to deviations," says Sébastien Peres.

The advantages of IO-Link are therefore obvious. Suppliers of machines or entire process units (skids) for food production in particular tend to integrate IO-Link-capable sensors and actuators. The majority of IO-Link sensors can be optionally operated in the analogue mode by simply changing the device configuration. This means that work processes in production can initially remain in place as part of retrofit projects. If, in addition to the actual process parameter, additional information such as diagnostic and service data is required later on, an installed IO-Link-capable device can simply be converted to a digital signal. One example of this are the FLOWave flow meters from Bürkert Fluid Control Systems, which have recently become available with IO-Link in addition to a 4 to 20 milliampere interface and Ethernet.

Even if IO-Link is not the most powerful communication standard for process engineering, it enables simple integration into established fieldbus systems. This in turn provides for communication at the lowest field level, allowing additional process and diagnostic data to be obtained from the sensor. Nevertheless, IO-Link is not a fieldbus, but is based on a point-to-point connection between the IO-Link master as a field device and the respective sensor or actuator. That means: Even modern sensors with an IO-Link interface are not cloud-capable per se. A master module is required that communicates with the higher-level PLC via Ethernet or other automation protocols such as Profinet. This can then forward the data to the cloud via a gateway using protocols such as OPC UA or MQTT. The gateway is the actual bridge between IO-Link and the cloud. It receives data from the IO-Link master and converts it into a cloud-compatible format. Optimised for the IIoT, the Industrial Internet of Things, the technology offers everything required for flexible cloud applications. This means that Industry 4.0 applications can be easily realised by retrofitting without having to replace the control unit or intervene in the control system.