The following figure illustrates the interactions between the website and the OPC UA ReferenceServer:
Restrictions on cross-site scripting require the web server to forward requests to the HTTP endpoint exposed by the OPC UA ReferenceServer.
A BadUserIdentityToken rejected error will appear if not logged in. The access token is sent to the server as the Authorization header in the HTTP request.
The syntax used to specify NodeIds is defined in Part 6.
Note that this example only allows writes to values that accept numbers as inputs. This was to keep the example as simple as possible.