Read Custom Signal Names in LabVIEW From an HWS File Created in DWE

[Jordan F]

Introduction

This vi reads the signal names in an HWS file created in Digital Waveform Editor with LabVIEW.  Before running the program, it is required to install the Hierarchical Data Format utility (HDF5). This utility accepts an HWS file and will return the underlying HDF structure required to view or adjust certain properties.

The block diagram below shows the programming flow using the HDF5 library to read in the signal names from the HWS file in LabVIEW. The property  /wfm_group0/traces/trace0/render_info/digital/bit<n> corresponds to the name of each of the lines in the waveform file.

[Larry.]

Hi,

using this vi I met a problem with HWS that contain more than 32 channels, what can I do to make it works anyway?

Thank you!

[James_P]

The file H5G Find-Open Numbered Groups.vi assumes that the 'bit#' groups are numbered sequentially from 0, stopping the search at the first missing #.  Editing that VI to find arbitrarily numbered bit groups may correct your issue Larry. 

I've noted in one of my projects that the bit groups are NOT numbered sequentially, but rather as bit0..bit31 then bit256+.  I had less than 64 signals, but I'd guess the numbering pattern continues with an 8-bit shift every 32 signals. 

[Larry.]

Thank you deadcool, I've checked but my HWS file has sequential signals.

The file that I've to manage is to big to post it, but also if I process the following example that I've created I get from the .vi just 32 channels.

https://decibel.ni.com/content/docs/DOC-21769

Can you try it for me?

[James_P]

Larry,

The names of your signals are sequential, but the group identifiers (hidden) used by the HWS file are not.  You can open the file using HDFView (http://www.hdfgroup.org/hdf-java-html/hdfview/) and look at/wfm_group0/traces/trace0/render_info/digital/ to see the bit identifier/signal name relationship. 

A sloppy fix would be to replace the while() loop in H5G Find-Open Numbered Groups.vi with a for() loop that has N wired to a large number (1000?).

[Larry.]

Now all is more clear, thank you!

To extract all the name from my .hws I have to do more than 1000 loops also if my file was made by about 170 signals...

Thank you again for your help!

[JChristensen]

I tried this tool but I get error when reading in the file. Is there a compatiblity problem with HWS 1.5.1? or Digital Waveform editor 3.0?

Error -1 occurred at ERROR: H5FD_sec2_open : unable to open file [maj(04): File interface : (min12): Unable to open file
ERROR: H5FD_open : open failed [maj(22): Virtual File Layer : (min23): Unable to initialize
ERROR: H5F_open : unable to open file [maj(04): File interface : (min12): Unable to open file
ERROR: H5Fopen : unable to open file [maj(04): File interface : (min12): Unable to open file

This error code is undefined. Undefined errors might occur for a number of reasons. For example, no one has provided a description for the code, or you might have wired a number that is not an error code to the error code input.

Additionally, undefined error codes might occur because the error relates to a third-party object, such as the operating system or ActiveX. For these third-party errors, you might be able to obtain a description of the error by searching the Web for the error code (-1) or for its hexadecimal representation (0xFFFFFFFF).

[Rahul_S]

Hi, I am not able get HWS pallete in LabVIEW. I have installed NI-HSDIO driver, NI-Scope, NI-DAQmx. Could someone reply what could be an issue. Thanks.