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Read Unscaled TDMS Data in LabVIEW

When a TDMS file, group, or channel contains scaling information (i.e., NI_Scale[nn] properties), the TDMS Read function returns the scaled data (it applies the scaling info to the raw integer data).

 

Is it possible to retrieve the raw, unscaled integer data?

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I did some experimenting many years ago with replacing the scaling to a 1-to-1.  In my limited testing it worked, but I also made an Idea Exchange item for it.

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Thanks. I considered modifying (or deleting) the scale properties.

 

What I was really hoping for was a way to read the raw values without modifying the file. Then read the scaling properties and use them at my discretion. 


It’s strange to me that this isn’t an option.

 

In my case I have raw I16 data that is much smaller memory footprint than FP32. For efficiency I’d rather work with the I16 and scale later.

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Sorry for opening an old thread without a solution, but

 

npTDMS has an option for reading raw data (scroll drown to the Scaled Data section)

 

I assume NI wrote the API for npTDMS, why don't we have this option in LabVIEW 😞

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@mcduff wrote:

Sorry for opening an old thread without a solution, but

 

npTDMS has an option for reading raw data (scroll drown to the Scaled Data section)

 

I assume NI wrote the API for npTDMS, why don't we have this option in LabVIEW 😞


npTDMS is written by Adam Reeve.

ZYOng_0-1698706059691.png

 

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Control Lead | Intelline Inc
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@ZYOng wrote:

@mcduff wrote:

Sorry for opening an old thread without a solution, but

 

npTDMS has an option for reading raw data (scroll drown to the Scaled Data section)

 

I assume NI wrote the API for npTDMS, why don't we have this option in LabVIEW 😞


npTDMS is written by Adam Reeve.

ZYOng_0-1698706059691.png

 


Maybe not NI; but I assume he is using a NI supplied DLL. He could have wrote everything from scratch which would be quite impressive. But anyway, we are a second class citizen with respect to TDMS. I would love to read raw data instead of scaled doubles like the OP asked. It seems possible.

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