The OPC UA systems architecture models Clientsand Serversas interacting partners. Each system may contain multiple Clientsand Servers. Each Clientmay interact concurrently with one or more Servers, and each Servermay interact concurrently with one or more Clients. An application may combine Serverand Clientcomponents to allow interaction with other Serversand Clientsas described in 6.3.7.

Clientsand Serversare described in the sub-clauses 6.2and 6.3. Figure 3illustrates the architecture that includes a combined Serverand Client.


Figure 3– OPC UA System architecture