TOX^® software with certified OPC UA communication: Standardized Data Exchange for Networked Manufacturing

In networked production, machines and systems are increasingly required to exchange data with higher-level systems. OPC UA (Open Platform Communications Unified Architecture) provides a vendor-neutral communication standard for this purpose. It enables the secure and standardized exchange of data between machines, systems, and higher-level IT systems. TOX^® software already supports OPC UA as a standard interface. Certification by the OPC Foundation has now independently confirmed its standards-compliant implementation.

The certified TOX^® software is implemented as an OPC UA server. Certification was granted for OPC UA specification version 1.04 for the 2017 UA Server Profile and the Machinery 1.x Information Model. The interface enables machine, process, and quality data to be made available across systems. This allows the TOX^® software to communicate, for example, with HMI, SCADA, MES, analytics, and IT systems.

For TOX^®, certification was already part of the plan when the decision was made to support OPC UA as the standard interface. A specific customer project ultimately provided the impetus for its implementation. The reason for this is that companies sometimes define their own specifications for interfaces, which must be met before the system can be deployed in production.

“With this certification, we can provide our customers with independent proof that our OPC UA interface complies with the underlying standard,” explains Tobias Hainmüller, R&D Software Team Leader at TOX^® PRESSOTECHNIK. “This means the customer does not have to perform this verification themselves. This can significantly reduce the coordination and testing effort, particularly in the case of large-scale integration projects.”

For the TOX^® software, OPC UA communication is part of its middleware functionality. This means that process and quality data can not only be archived locally or on the network, but also transferred to other systems via communication protocols such as OPC UA or MQTT. OPC UA certification provides a reliable foundation for this data exchange.

The certificate is issued by the OPC Foundation. The required testing is conducted by authorized certification bodies in accordance with the Foundation’s guidelines. Throughout the process, TOX^® Software Development maintains close communication with the certification body. Test results are analyzed, outstanding issues are resolved, and next steps are coordinated.

A maximum time frame of six months is allocated for the certification process. All required tests must be successfully completed within this period. To prepare, developers can use the Compliance Test Tool (CTT) to simulate tests in advance. This allows potential discrepancies to be identified and addressed even before the actual certification tests take place.

On the TOX^® side, the certification was implemented by the software team. Johann Wesely is primarily responsible for developing the OPC UA interface. Christian Kieble is handling the integration with the TOX^® software’s quality data system.

A key technical challenge in OPC UA communication is clearly defining the required data and ensuring consistency across the participating systems. Even differences in terminology can complicate data mapping. If data is needed that has not yet been transferred from the controller to the TOX^® software, it must first be determined whether this data can be obtained and subsequently made available to the software.

For customer-specific applications, an XML structure is developed in collaboration with the customer based on the required data scope to serve as the foundation for communication. The TOX^® software, acting as an OPC UA server, provides the corresponding data and notifies the customer’s client, which then reads it. In the certification process, however, a defined server structure is established. Here, the focus is, among other things, on verifying data validity, value ranges, and update intervals.

“Certification goes well beyond simply providing an interface,” says Tobias Hainmüller, R&D Software Team Leader. “During testing, it becomes very clear exactly which data and functions must be available to ensure fully standards-compliant communication. These insights are directly incorporated into our software development.”

The experience gained from the initial certification process will also be incorporated into the future development of the TOX^® software. Additional data and functions required to meet the certification criteria have been integrated into the software and the underlying data exchange. This allows TOX^® to build upon a foundation that has already been tested when making future changes.

The certified OPC UA communication complements the functions of the TOX^® software for networked production. It supports the setup, operation, and monitoring of industrial pressing and joining processes and enables process data to be collected, evaluated, and documented in a traceable manner for quality assurance purposes.