Small helpers, big impact

How a customised OPC UA tool simplifies the machine data connection of injection moulding machines

In the world of Industry 4.0 and the Industrial Internet of Things (IIoT), data plays a crucial role. Machine data in particular enables the automatic collection of valuable information on the shop floor to determine the OEE (Overall Equipment Effectiveness).

But sometimes seemingly simple tasks present us with unexpected challenges. This is what happened to me recently with the manufacturer-independent machine connection of injection moulding machines. All manufacturers (for example: KrausMaffei, ENGEL, Arburg and others) have agreed on the Euromap 77 and Euromap 83 standards for digitalised plastics processing and MES connectivity and published a joint OPC UA Companion spezification . However, as always, the devil is in the detail: the data provided by the machines via the OPC UA server must be validated and compared with reality.

The search for the right tool

For this task, I needed a reliable OPC UA client and data logger. It quickly became apparent that the existing solutions were not optimal:

• UA Expert, a free OPC UA client, could only log tags of type Double.
• Commercial tools are oversized for the task with limited, time-limited free versions.
• Open source OPC UA implementations and SDKs offered either rudimentary clients or no ability to persist history.
• Commercial SDKs also required customised developments to meet the requirements.

The solution: A customised OPC client based on open source

The Python FreeOPCUA Client with graphical Qt user interface and the graphical Node.js OPC UA CLI Commander turned out to be the most promising solutions. Due to the GUI, I then decided in favour of the Python implementation as the basic tool, as it already has a good basic range of functions. However, I had never written a QT application in Python before.

In this situation, I turned to Claude.ai mit der 3.5 Sonnet Engine, as it advertises itself as being particularly good at solving programming tasks and is one of the most up-to-date and powerful large language models on the market. The tool was at the top of my list of tools that I wanted to evaluate and test for daily use. The result of half a day of LLM-supported programming is a FreeOPCUA client fork with a DuckDB connection. This tool makes it possible to log a history of all tags that the user has subscribed (subscribe to data change) to in the GUI in a DuckDB database

Advantages of DuckDB

DuckDB is an embedded analytical database that is particularly suitable for this application:

• 1. High performance for analytical queries.
• 2. Easy integration without separate database installation.
• 3. Columnar storage for efficient data processing.
• 4. SQL support for flexible queries.

The data model used is deliberately kept simple and flexible.

The data model

This schema makes it possible to store all relevant information for each logged data point, regardless of the specific OPC UA data type.

Practical benefits and outlook

With this customised tool, I was not only able to successfully validate the EUROMAP 77 and 83 OPC UA implementations of the various manufacturers, but also map the production processes in detail using machine data acquisition via OPC UA, regardless of the manufacturer. Based on this data, the variables required for the OEE calculation were identified and validated.

This connection now forms the basis for recording and optimising the OEE in our customer's Manufacturing Execution System (MES). This enables us to continuously improve production processes and increase efficiency.

Conclusion

This experience shows me how LLM significantly speeds up and simplifies programming and how small, customised tools can solve major challenges. At a time when Industry 4.0 and complex systems often take centre stage, we should not underestimate the power of simple, targeted solutions. They can not only solve immediate problems, but also pave the way for further optimisation and innovation.

Would you like to find out more about exciting topics from the world of adesso? Then take a look at our previous blog posts.