The OPCDA.NET Professional Edition provides two invisible Windows Forms components that handle the server access and reduce coding requirements significantly.

• The DAServer control maintains and supervises the server connection
• The DAGroup control handles read/write access and Data Change callbacks

The controls are optimized for Windows Form application but can also be used in Windows Service application.
For WPF these controls are not yet available. The current version of the WPF Designer doesn't provide the features needed in the property dialog editors.

 

 

Sample Project

The Windows Form application has the invisible DAServer and DAGroup controls added. These controls are configured in the Visual Studio Designer for the details of the OPC server and the items to be accessed. Servers and item details can be typed or browsed and selected for a quick configuration.

 

 

 

 

Sample Code

The following image shows the complete sample application code. It uses the OPCDA.NET controls to connect to the server and subscribe items.
The controls contain high quality OPC server access code. The server connection is supervised and time out checked. On errors the OPC server is reconnected.

Disregarding error handling the DAGroup.Create() method is the only method that must be called to start the OPC server according the configuration definitions. 

 

 

Executing Application

The application shows the current values of two items and status information.

 

 

See the DACtrlSample1 application for a sample application that uses more features of the DAServer and DAGroup controls.