OPCDA.NET is .Net assembly that wraps the OPC DA V2/V3 Custom Interface to .NET. OPC clients can be developed in any .Net compatible language.

Application generation wizards are provided for Visual Basic and C#. These wizards create a Visual Studio project with a small sample application according the feature selection in the wizard dialog.
HINT: Using the wizards to create a sample application with the features of interest is often quicker than looking trough the sample applications.

The easiest way to create a OPC client application is by using the invisible DAServer/DAgroup controls provided by the OCPDA.NET Professional Edition. Coding requirements are greatly reduced. Much of the configuration is done in the Visual Studio Designer and high quality server access handling is encapsulated in the controls.

Sample applications are provided for Visual Basic .NET and C#. These sample programs use many OPC functions and can be studied to to see how OPC servers can be accessed and how the different OPCDA.NET features are used..

 

The wrapper assembly offers most functions defined in the OPC DA custom interface specification. The data types of parameters and result are converted into .Net types so that usage is convenient and simple. All functions are specified in this help documentation and most of the explanations provided in the OPC specifications are also part of this help. Study of the OPC custom interface specifications should be necessary only in rare cases.

Read the Getting Started chapter for an overview of the client development process and the program structure.

OPCDA.NET provides development support beyond the .NET wrapping. It offers extended browse support ( BrowseTree, ShowBrowseTree, ShowBrowseTreeList ) that makes is easy to browse the server, display the branches/items and select items. For client applications with a predefined set of items the item names can be loaded from an external or embedded XML file using the ItemListLoader helper class. This item definition XML file can be interactively created with the ItemListBuilder tool.

 

OPCDA.NET can be used with the DANW-Xi option to access OPC DA and OPC Xi servers through the same API. The DANW-Xi option is an Advosol product that need to be purchased separately from OPCDA.NET.

OPCDA.NET can be used with the DANW-UA option to access OPC DA and OPC UA servers through the same API. The DANW-UA option is an Advosol product that need to be purchased separately from OPCDA.NET.

 

OPCDA.NET Versions

Most OPCDA.NET versions are fully backward compatible. However, the strong named OpcDaNet.dll cannot be replaced with another version without making a configuration definition.

A version redirection has to be defined in the application configuration file. This configuration file must have the same name as the application and must be in the same directory as the application exe file.

 

The following sample application configuration file redirects older OPCDA.NET version to V10.0.
The redirect definition is required if a newer OPCDA.NET DLL is used without the application being rebuilt with a reference to the newer version.

<?xml version="1.0"?>
<configuration>
   <runtime>
       <assemblyBinding xmlns="urn:schemas-microsoft-com:asm.v1">
          <dependentAssembly>
              <assemblyIdentity name="OpcDaNet" publicKeyToken="5b58a8d8b6f4763b"/>
              <bindingRedirect oldVersion="5.2.0.0-10.0.0.0" newVersion="10.0.0.0"/>
          </dependentAssembly>
          <dependentAssembly>
              <assemblyIdentity name="OpcDaNet.Net4" publicKeyToken="5b58a8d8b6f4763b"/>
              <bindingRedirect oldVersion="5.2.0.0-10.0.0.0" newVersion="10.0.0.0"/>
          </dependentAssembly>
       </assemblyBinding>
   </runtime>
</configuration>