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Decoding LabVIEW data files..

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Hi,

we have lot of old data files created by LabView about 20 years ago. The files contain graph data in binary format and some other LV info.

 

Is there any possibility to read the graph data by using own custom software made in C# or C++? I need just info how the graph data is coded so can then decode it.

I would like to import the graphs into SQL server. It is not possible to make this job manually by hand because there are too many files. So I need to make a program for the transfer.

BR,
Ilkka

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Message 1 of 10
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LabVIEW is just a programming language and does not specify any specific binary file format. It was up to the programmer to decide how the binary data is arranged and thus how it can be parsed later.

 

Do you have the LabVIEW code used to write the files? In that case it would be easy to reverse engineer the process in any other programming language.

 

Sometimes an analysis of the binary files can be done by educated guessing, if it is not too complicated. Do you know the datatype of the data (DBL, SGL, I16, etc.) How much metadata is there (headers, etc.?). Do you know what "some other info" contains? Most likely, any multibyte data is stored in big endian format.

 

There is no such thing as "graph data". I would guess it is just data, maybe with some axis information.

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Hi,

 

There seems to be a Write to Binary File Function VI in LabVIEW. Just thought, if that is used.

Screenshot 2023-05-26 180312.png

 

I have tried to contact the company, who has made the LV program. But they have not replied. 

 

I attached one data file into this message. I opened it also with a HEX editor but little challenging to get the starting point of the data arrays.

BR, Ilkka

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The company has made also an exe program, which can open the data files and show the recorded curves. But I have no source code.

Screenshot 2023-05-26 181029.png

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Message 4 of 10
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Write to binary file just stores flat binary data. You said the file also contains "other info", so most likely they used custom code. I'll have a look.

 

A file is just a linear string of bytes. One clue is the *.rdd extension. That might be a documented standard.

 

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@Yltsä wrote:

The company has made also an exe program, which can open the data files and show the recorded curves. But I have no source code.

Screenshot 2023-05-26 181029.png


Depending how old the runtime engine is, try to right-click the graph and see if you get an "export..." menu. You might be able to get the data out this way.

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Message 6 of 10
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Solution
Accepted by topic author Yltsä

So looking at the file content in \-code, it contains text and binary data and various sections

 

altenbach_0-1685118477165.png

 

 

The first four characters are DTLG, so it is possible that we are dealing with a "datalog" file structure. Start reading here.

 

 

 

Message 7 of 10
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Yes, there is an export to CSV.. But we have these files a lot, maybe over 10000 files .. or 100k. I have to make an automated import and it would be best to read the binary data directly.

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Message 8 of 10
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Thanks a lot. You are right; this is possible to read.

I start hacking files next week. This is very interesting..  😉

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Hi. I have the same situation like yours .I want to write a python program to process the data which is ended with .dat_ads. The software of our lab was developed may be 10 years ago. A part of this file is encoded and I can't read it.This data is a curve about time and current.I will appreciate if you can help me to decode this.

Screenshot 2023-07-19 151624.pngScreenshot 2023-07-19 151650.png

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