The ResourceUriparameter of DataType Stringenables the transport implementation to look up a configured key from the corresponding KeyCredentialConfigurationTypeinstance defined in OPC 10000-12to use for authenticating access to the broker at the connection level or for queues configured below the connection.

If null, no authentication or anonymous authentication shall be assumed as default unless authentication settings are provided on a subordinated WriterGroupor a DataSetWriterto authenticate access to individual queues.