User`s guide

18 Agilent VISA User’s Guide
2 Building a VISA Application in Windows
Building a VISA Program (Visual Basic)
This section provides guidelines for building a VISA program in the
Microsoft Visual Basic (VB) language, including:
• Visual Basic Programming Considerations
• Sample VISA Program (Visual Basic)
Visual Basic Programming Considerations
Some considerations for programming in Visual Basic follow. This
information applies to Microsoft Visual Basic version 6.0; for
information on building a VISA application in Microsoft Visual Studio
.NET, see the VISA Online Help.
Required Module for a Visual Basic VISA Program
Before you can use VISA specific functions, your application must add
the visa32.bas VISA Visual Basic module found in C:\VXIPNP\
WinNT\include\ (assuming default installation directories).
Adding the visa32.bas File to Your Project
To install visa32.bas:
1 Select Project > Add Module from the Visual Basic 6.0 menu.
2 Select the Existing tab.
3 Browse and select the visa32.bas file from the applicable
directory (by default, C:\VXIPNP\WinNT\include\).
4 Click the Open button.
VISA Limitations in Visual Basic
VISA functions return a status code that indicates success or failure of
the function. The only indication of an error is the value of a returned
status code. The VB Error variable is not set by any VISA function.
Thus, you cannot use the ON ERROR construct in VB or the value of
the VB Error variable to catch VISA function errors.