27.3.2 Advanced API Calls

27.3.2 Advanced API Calls Bwdllobj (an Atl COM Dll) or viewdll.dll (a Win32 Dll)

Visual C, Visual Basic users can develop their own interface to WebAccess using our Bwdllobj or viewdll.dll.

Bwdllobj also supports VB 6.0, VBScript, JScript, and VB.NET.

Note - JScript and VB Script are also supported by ACTION Commands used by Local Scripts and Global Scripts in WebAccess.

Visual C and Visual Basic use these Applications Programming Interfaces as the API for User-developed programs. The following commands are not needed for most applications. A User programs make calls to the viewdll.lib.

The viewdll.h, viewdll.lib, viewdll.dll, and webvsid.dll are located in the webaccess\node directory.

In order to resolve “stack overflow” issue when VB programs are used to call viewdll.lib, a new COM object is added to WebAccess. The functions defined in the new viewdll.bas illustrate how to use this new object. To use this viewdll.bas directly, please add this file into VB project and call the functions directly.

To test Bwdllobj on VB.NET, please install the latest version of WebAccess Node on the SCADA nodes and then upgrade the sample VB project using VB.NET upgrade wizards.