OPC UA Server Development

OPC UA servers combine the functionality of all earlier OPC specifications (DA, AE, HDA) and support many new features. A UA server is therefore significantly more complex than current OPC DA servers.
The UA core implements a network database with nodes that describe items and item attributes. The nodes can be linked in a complex manner, allowing all kinds if information structures to be modeled. Network databases are difficult to implement therefore the more restricted relational databases are far more widely used.
The OPC Foundation implements a reference UA server and probably all UA server products will base on this reference implementation.

The server developer has to map the device data into the UA server network database. The complexities of the network database are less of an issue for the server developer than they are for the client developer. The server developer is free to choose a structure, either simple or elaborate. The client developer has to deal with different structures used in different servers.

Currently most OPC application use only the Data Access (OPC DA) functionality. This will probably not change because of OPC UA and therefore UA server SDKs could provide a DA specific mapping. This would bring the UA server development and configuration to the same level of complexity as the development of an OPC DA server based on a server toolkit product.

Advosol offers the uaPLUS OPC UA Server Toolkit for UA servers with DA/HDA/AE/Methods functionality. It bases on the latest version of the OPC Foundation OPC UA SDK.
The uaPLUS Server Toolkit uses the same device handling plug-in .NET assembly as the Advosol DANSrv OPC DA .NET Server Toolkit and the Advosol XML DA Server Toolkit. Users of these toolkits can offer UA servers without having to develop any code. The previously developed plug-in DLL can be used with the uaPLUS generic UA server.
The uaPLUS server toolkit can be used in combination with the DANSrv toolkit for server with UA and Classic OPC DA capability.

Another option to support UA is with converter servers. Instead of replacing the Classic OPC server a converter server is added. This approach has the advantage that existing classic OPC servers don’t have to be modified and Classic OPC clients can still access.
Advosol offers the UAtoCOM converter server with easy to use configuration tools.