As defined in OPC 10000-14, DataSetReaders in a ReaderGroup may extract their DataSetMessages from different NetworkMessages. However, it is recommended that the PubSubConfiguration generated for an AutomationComponent contains a ReaderGroup for each PubSubCommunicationFlowConfiguration. By this, common parameters (e.g., SecurityGroupId, SecurityKeyServices, TransportSettings, or MessageSettings) are configured on the ReaderGroup and do not need to be repeated in each DataSetReader.
For the example illustrated in Figure E.5, a ReaderGroup in AC_A is generated based on the parameters in SubA, a ReaderGroup is generated for each AC_B based on the parameters in SubB, and a ReaderGroup is generated in AC_C based on the parameters in SubC.
Figure E.21 – ConnectionConfigurationSet and ReaderGroup
Figure E.21 illustrates the relation between the SubscriberConfiguration and the PubSubConnection and ReaderGroup within the PubSubConfiguration. Note that the SubscriberConfiguration uses information from the parent Object as illustrated.
It is recommended to update PublisherId after issuing the ReserveCommunicationIdsCmd; see E.2.1 for details.
For a Subscriber, the Address will be in the PubSubConnection. See 220.127.116.11 on how to set the Address.
TransportProfileUri is used to set up the information in the PubSubConnection, whereas HeaderLayoutUri, PublishingInterval, Qos, SecurityMode and SecurityGroupId are used to set up the information in the ReaderGroup.
The PubSubConnection elements ConnectionProperties and TransportSettings are transport specific. For the UDP-UADP, both are set to null.
SecurityKeyServerAddress is set in the ReaderGroup only if a pull model is to be configured (for additional details, see 9.3.2).
For MaxNetworkMessageSize, follow the recommendations in OPC 10000-14.