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Compliance Corner – June 2024

    What’s new in OPC UA Certification

    We posted a new release of the CTT earlier this month (available here). Like in most cases, this is not only a maintenance release, but it also includes some new OPC UA Features. This includes testing for A&C Instances and Branches which completes the automatic A&C testing;  but the key addition is a new extension that can be used to test Off-line descriptors mandated for products implementing the OPC UA FX specifications.

    At this point in time, the test cases for a descriptor that have been implemented in the new component are very basic. They can check the basic structure of the descriptor and that it is a valid AMLx file with a valid signature.  In future releases, both the component and the test cases will be enhanced to add additional functionality, including full testing of the content of an AML file and verification of the content against the UA Application. Nevertheless, we encourage all users of the CTT to test their UAFX implementations to verify the new extensions and provide their feedback.

    This latest release of the CTT also included multiple additions for UAFX testing, further expanding the testing that is available. The target is still to provide initial UAFX certification at the end of the third quarter of 2024. A key reminder is that FLC requires that all UAFX applications are tested.  A manufacturer is not allowed to use the UAFX or OPC UA FX protected identities to describe their products, unless it has been tested.

    The test lab has also started to see an increase in products that have implemented features from companion specification that requires certification, such as MDIS Client and Server and O-PAS™ profiles.  The O-PAS™ profiles are now available in the profile application (, making the testing of OPC UA features required by O-PAS™ simpler.

    Also, our work on providing testing of OPC UA Companion Specifications has continued. In May, we published the test scripts for the OPC UA 40200 – UA for Weighing Technology specification. The test scripts can be downloaded (available here) and then imported to your existing CTT test project to extend the core OPC UA testing to verify your UA for Weighing Technology implementation. If you are looking for testing of another companion specification, please get in touch with us.

    If you have questions on these topics or are interested in getting involved in our activities, please do not hesitate to contact us at

    We wish everyone a relaxing summer break and if you use the quite time to test your products, please let us know about any findings you may have.

    Paul & Alex