Splitting Digital Waveform

[kdoorc]

Hello,

I am continuously collecting several digital signals using NI-HSDIO and a PCI-6552. I would like to save all collected waveforms into one HWS file (using a modified version of the Continuous Acquisition- Stream to Disk example VI) and then split the waveforms out into their various channels so that they can be processed by other VIs. Is there any way to do this using digital signals that are not dynamic data?

I would also appreciate any suggestions on how to save the split waveforms as an array to file, or how to split the waveform and save each waveform as a separate file.

Many thanks,

Kristen

[JaredW]

There is a LabVIEW VI called "Digital Signal Subset". It is found in the Programming-->Waveform-->Digital Waveform palette.

This VI will take a single waveform and index out specific signals into a new waveform. You can call this VI within a for loop to index out each signal to create an array of waveforms with one signal in each array element. See the example VI I've included.

Now for saving each signal individually. NI-HWS has the ability to save mulitple waveforms in one file. The niHWS New Wfm Reference VI has a string input called waveform name. You can us this VI with an input waveform name multiple times on the same file reference to create multiple named waveforms within a single HWS ifle. Then to read the waveform, you will need to use the niHWS Open Wfm Reference multiple times with the same waveform names as were used for saving.

[kdoorc]

Thank you, JaredW, I think that solution will work perfectly. Is there any way you can save your example VI so that it is compatible with 7.1? I haven't upgraded yet.

Thanks,

Kristen

[JaredW]

Kristen,

Ok, things are more difficult in LabVIEW 7.1.  There were very few support VIs for digital waveforms in LabVIEW 7.1.  LV 8.0+ has many more digital support VIs. The VI I referenced for you to use was not added until LV 8.0.

So, I wrote another VI for you that essentially does what the LV 8.0 VI does. Subsetting signals from a DWDT is not an easy task in 7.1.

-Jared