Using HWS Files in a 64-Bit NI Development Environment

Updated Jun 11, 2023

Reported In


  • LabVIEW



Issue Details

I have been using Hierarchical Waveform Storage (HWS) files to log data from my Modular Instruments (NI-SCOPE, NI-FGEN etc) in a 32 bit application. I recently migrated to a 64-bit application and the HWS functions return this error in LabVIEW:

And this error in LabWindows/CVI: This function is not supported on 64-bit platforms.
Can I use HWS file in a 64-bit application?


NI-HWS VIs are only supported in 32-bit NI development environment, not 64-bit.
NI-HWS files are based on the HDF5 file format which is designed to store and organize large amounts of data. As an alternative to this, NI recommends using TDMS files as a means to store and and organize large data in binary format.

Additional Information

Refer to What Are TDMS Files and How Can I Use Them in My LabVIEW Program? to learn about TDMS files and modify your existing VI to leverage them. 
If you have existing log files in HWS format, refer to How Do I Convert a HWS File to a LVM or TDMS File in LabVIEW?  to learn how to convert them to TDMS files.