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6.3 OPC UA Servers ToC Previous Next

6.3.7 Server to Server interactions ToC Previous Next

Server to Server interactions in the Client Server model are interactions in which one Server acts as a Client of another Server. Server to Server interactions allow for the development of servers that:

  1. exchange information with each other on a peer-to-peer basis, this could include redundancy or remote Servers that are used for maintaining system wide type definitions (see Figure 6),
  2. are chained in a layered architecture of Servers to provide:
  3. aggregation of data from lower-layer Servers,
  4. higher-layer data constructs to Clients, and
  5. concentrator interfaces to Clients for single points of access to multiple underlying Servers. Figure 6 illustrates interactions between Servers.

readme_files/image008.png Figure 6 – Peer-to-peer interactions between Servers

Similar peer-to-peer interactions can also be accomplished using the OPC UA PubSub model where each peer Application is both a Publisher and a Subscriber.

Figure 7 extends the previous example and illustrates the chaining of Servers together for vertical access to data in an enterprise.

readme_files/image009.png Figure 7 – Chained Server example

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