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Undefined Symbol Error in LabWindows/CVI with VXI and GPIB 488.2 Libraries

Updated Dec 22, 2017

Reported In


  • LabWindows/CVI Full
  • LabWindows/CVI Base

Issue Details

I am upgrading a LabWindows/CVI project that uses NI VXI or GPIB libraries to LabWindows/CVI 2013. When I build the project, I receive undefined symbol errors for each of the VXI or GPIB functions in my project. I did not receive these errors in earlier versions of LabWindows/CVI and have not changed any project settings. What is causing this error and how to I resolve it?


This error occurs when the LabWindows/CVI linker cannot find the .lib file for the VXI or GPIB libraries. These libraries can be automatically linked into projects from the Library»Customize Library Menu dialog. Select VXI or GPIB/GPIB 488.2 to add these libraries to the LabWindows/CVI Library Menu and enable them to be linked to projects. 

In earlier versions of LabWindows/CVI, a stub version of these libraries was automatically linked to projects when the VXI or GPIB/GPIB 488.2 libraries were disabled. This stub version allows projects with VXI or GPIB references to be built when the vxi.lib and gpib.lib libraries are not on the system. 

You may find the stub files in the following locations:
  • GPIB — <National Instruments>\CVIversion\bin\msvc\gpibstub.obj
  • VXI — <National Instruments>\CVIversion\bin\msvc\vxistub.obj
Where version is the version number of LabWindows/CVI you are using. You can add the stub files to your project to build your project without the .lib files.

The "Undefined Symbol" error is generic and can appear in a lot of cases. Other cases in which you could get that error are listed below.