The term 'Industrial Internet of Things' is used to classify approaches that make data from the store floor available on platforms on the internet. This can be measured values from sensors, for example, but also data from other components of machines and systems. Traditionally, such data is used directly at the control level, where both storage space and computing power are scarce.
For the use case of condition monitoring as a basis for predictive maintenance approaches, however, larger amounts of data must be stored over longer periods of time in such a way that they can be accessed quickly and effectively. This requires suitable database structures, such as those available on cloud platforms. Modern communication modules for sensor/actuator communication support the IoT protocol MQTT, which is often used for cloud communication, in addition to the fieldbus protocols such as Profinet or Ethernet/IP that are usually used to connect to control systems. This protocol can be used to transfer data from the sensor/actuator level directly to cloud instances provided by Amazon Web Services, for example - in parallel with fieldbus communication.
This means that the global infrastructures of the so-called 'hyperscalers' can be used for automation. Data from machines and systems is available worldwide, so that information can be made available exactly where it is needed. The various application packages offered on the platforms can also be used: With little configuration effort, clear dashboards can be designed or algorithms supported by artificial intelligence and machine learning can be used. Particularly interesting applications here are anomaly detection and parameter optimization to adapt machines to changing environmental conditions.

Nothing works without digital twins

Communication modules for sensor/actuator communication: The IO-Link masters ICE 2 and ICE 3 from Pepperl+Fuchs are certified as 'AWS Partner Device'.

© Pepperl+Fuchs

When visiting Hannover Messe 2023, it was easy to get the impression (to paraphrase Loriot) that automation without digital twins is possible but pointless: digital twins are provided for many components and systems are advertised that can process them more or less directly. However, caution is required when making this assessment, as not all 'twins' are the same. The term 'digital twin' is not standardized and is often used for descriptive data records in proprietary formats that can only be used within the product world of a few or even just one manufacturer. No interoperable scenarios are possible with such data.
With the Asset Administration Shell (AAS), however, an open concept was developed and introduced into standardization as IEC 63278. The concept divides the administration shell into domain-specific submodels, which in turn contain descriptive characteristics for relevant properties of the respective domain. This division into submodels ensures the extensibility of the overall concept and also enables specialists from different domains to work on submodels independently of each other in parallel.

The International Digital Twin Association (IDTA) is responsible for coordinating the work on submodels, their certification, publication and provision. This organization, which was jointly founded by the VDMA and ZVEI industry associations and now has more than 100 member companies, is already working on or has already published more than 50 different submodels.

One of the first published submodels was the 'digital type plate', which combines all the information to be affixed to the type plates of automation components, such as the manufacturer's name, type, year of manufacture and serial number. The Machinery Directive stipulates which data must be listed here.

Identify connects

Benedikt Rauscher is Head of Global IoT / Industry 4.0 Projects at Pepperl+Fuchs in Mannheim.

© Pepperl+Fuchs

The connection between a physical component and its administration shell is established with the help of an 'identification link' applied to a physical component. The structure of such identifiers and their form as 2D barcodes are standardized in IEC 61406 ('Auto-Id'). With the help of the combination of identification link and administration shell, all information on the component, such as the manual, data sheet or installation instructions, can be made available digitally in a standardized form. The browser and end device such as a cell phone or tablet automatically select the appropriate language version and the manufacturer can update the documents with little effort.
For component manufacturers, there is a tangible economic benefit from the 'AAS' and 'Auto-Id' technologies if paper documents no longer need to be enclosed with the products. For users, the direct digital availability of information on the components used in their machines and systems is also advantageous, for example if the documents required for maintenance processes are available on site.
For these reasons, operators of process plants are already formulating requirement profiles for components to be used, according to which they must be identifiable in accordance with IEC 61406. At the same time, many component manufacturers are working on applying corresponding identifiers to their products.