The EasyUA CLient SDK includes:

• EasyUA.dll           for Windows Forms and Windows Console and Service applications
• EasyUA.WPF.dll    for WPF applications

The two DLLs differ only in the BrowseTree and UaDataBind classes, which display server data directly in Forms respectively WPF controls.

 

The EasyUA DLLs provide a set of classes that handle the OPC UA server communication.

The typical steps for an EasyUA based UA client application are:

• Create a UaClient object
• Load the UA configuration
• Create a session
• Connect to the UA server

 The application is now ready to access the server to browse for nodes or to read/write/subscribe nodes with known NodeIds.

 

 

Create a UaClient object

The UaClient constructor has one argument that controls the callback handling.
If a Windows Forms or WPF control object is specified the callbacks are synchronized with this object (handler is called thru Invoke).
Sample:
In Windows Forms or WPF applications:          uaApp = new UaClient(this);
In Windows Console or Service applications:   uaApp = new UaClient(null); 

 

Load the UA configuration

Every application needs to have a UA configurtion file in the executable directory.
The file name is   appname.Ua.Config.Xml

The UaClientConfigHelper utility is provided to create/edit the configuration file including the creation/import of certificates.

If it's not necessary to have application specific configuration settings or certificates then the property
     UaClient.UaAppConfigFileAutoCreate = "EasyUA Sample";
can be set to have EasyUA create a default configuration and certificate.

To load the configuration file the application must call the method:
    uaApp.LoadConfiguration(); // process the UA configuration

 

Create a Session

The Session can be created in two ways:

• With the UA server discovery URL and a selection for either minimal or maximal security
  Sample:  session = uaApp.CreateSession("opc.tcp://localhost:62849/Advosol/uaPLUSsim/discovery", false, "test");
• With a specific UA server endpoint
  Using server discovery methods the available endpoints can be retrieved from the server. The best suited one can be used>
  Sample:   session = uaApp.CreateSession( selectedEndpoint, "test");

 

Connect to the UA server

The application may first install event handlers for notifications and the Connect, either with or without user credentials.
Sample:    session.Connect(null);

 

 

 

Sample Applications

C# and VB.NET sample applications are provided for the different kinds of .NET applications:

The sample code is rather simple but includes important notification and error handling.
The WindowsFormsSample is more complex and uses many EasyUA features with synchronous and asynchronous server calls.