The logical identifiers allow PubSub objects be found in the PubSub configuration.

PubSub Connection Name, Writer Group Name, and DataSet Writer Name

A PubSub configuration contains a collection of PubSub connections, and each PubSub connection is identified by its name, which is a string. For publishers, a PubSub connection determines the physical publisher Id that is used by that publisher.

A PubSub connection contains a collection of writer groups, and each writer group is also identified by its name (a string). Each writer group has its physical writer group Id specified.

A writer group contains a collection of dataset writers, and each dataset writer is also identified by its name (a string). Each dataset writer has its physical dataset writer Id specified.

Published Dataset Name

In a PubSub configuration, each published dataset has a unique name (a string). Published datasets may be organized in a tree of (named) dataset folders. The name of published dataset, however, must still be unique across the whole PubSub configuration, not just in its dataset folder.

A dataset writer may be associated with a published dataset by means of published dataset name.

Logical identifiers with topic tree

When OPC UA PubSub Topic Tree is used, writer group name and dataset writer name are no longer considered logical identifiers.