NI-DAQmx 19.0 does not install the correct 64-bits NIDAQmx.lib file!

[LeDrull]

Hi. I've just installed the latest version of NI-DAQmx (v19), and got a LNK4272 error while trying to build a 64-bit C application using MSVC.

The cause of the error is that the "NIDAQmx.lib" file installed in the "C:\Program Files (x86)\National Instruments\Shared\ExternalCompilerSupport\C\lib64\msvc" folder is the same as that found in the "lib32" folder (both md5 checksums are identical).

Is there any other place where I can get the 64-bit version, or I should downgrade to v18 until the problem is solved?

[Ludovic]

Hello,

I've got the same problem.

Have you got an answer?

Best regards

[LeDrull]

Hello,

No answer yet. I just downgraded to 18.6 and everything works fine so far.

Guess we'll have to wait for 19.1 patch release.

Regards.

[Ludovic · Accepted solution]

Hello,

If you are interested, I worked around by recreating the .lib file.

• Download the attached .7z file and unpack the .def file.
• In Visual Studio, click on Tools>Visual Studio X64 command prompt
• Type this command line : lib /def:nidaqmx.def /machine:X64 /out:nidaqmx.lib

That's all!

Hope this can help.

Best regards

Ludovic

[LeDrull]

Thanks, now everything works as expected!

I didn't realize the LIB file could be recreated from the DLL...

[bstreiff]

Hi all,

This was a defect in NI-DAQmx 19.0; the installer was installing the 32-bit nidaqmx.lib to both the 32-bit and 64-bit locations. This has been corrected in NI-DAQmx 19.1.

If you can't upgrade, the workaround that @Ludovic posted above for generating a replacement nidaqmx.lib will also work.