An OPC UA PubSub dataset gains a field: how should subscribers handle the change?

DataSetMetaData describes field meaning and structure, including the ordered field definitions. The metadata must correspond to the published dataset layout. Treat the change as a schema change and update the relevant configuration version through the supported implementation workflow.

Check how subscribers obtain initial and updated metadata in the selected transport and product. Do not assume a subscriber can infer a new layout from a few bytes of payload. The specification describes an error condition when received data requires metadata the subscriber does not have.

Test an older subscriber, one that joins after the change and one that misses the metadata update. Define whether the rollout preserves a compatible dataset or introduces a separately versioned feed. Log the dataset identity and configuration version so decoding failures can be traced to the actual change.