Configuring the COM Wrapper

The app.config file for each of the sample applications contains a configuration section called Opc.Ua.SampleServer.

The section has the following elements which control the wrapper:

NamespaceUri	The URI for the namespace used by the wrapper.
BrowseName	The browse name of the folder that contains the wrapped server address space.
Url	The URL of the COM server.
SeperatorChars	Specifies the separator characters that the server uses for its item ids. This field is not required and is only used to improve performance when it is possible to extract the browse name from an item id.

Note
The COM server must be accessible to the server process. This is a particular concern when running the IIS hosted version of the server which runs using the ASPNET account.

Configuring the COM Proxy

The Opc.Ua.ConfigurationTool application is used to create COM servers that COM clients can connect to. The COM server stores all of the information required to connect to a UA server in the registry.

The Opc.Ua.ConfigurationTool application includes a wizard that will allow administrators to browse for servers using the Local Discovery Server, select an endpoint and then create a new COM server.

This application can also be used as a command line utility.

When a COM client connects to a UA server via the proxy it launches the OpcUaComDllHost.exe process. This is a local COM server written in C++ that wraps the Opc.Ua.ComInterop.DLL. The host process is required because .NET does not support EXE COM servers.

By default, errors connecting to the UA server are written to the OpcUaComDllHost.log.txt file in the same directory as the executable.