Working of buffer

[Dhruv1140]

How does the input buffer for File I/O works in Labview ?

[GerdW]

Hi Dhruv,

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@Dhruv1140 wrote:

How does the input buffer for File I/O works in Labview ?

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Which "input buffer" for which "File I/O works" are you talking about?

[Dhruv1140]

 write to text funxtion or any write to file function. How does it works and how big data log can I take by continuous reading. As per my understanding the buffer at write to text function will append data for every iteration and replace with previous data upto 4 gb only, So I will get the data log as text file upto 4 gb. Is my understanding is correct ?

[rolfk]

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@Dhruv1140 wrote:

So I will get the data log as text file upto 4 gb. Is my understanding is correct ?

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No. LabVIEW file functions are fully large file capable since 8.0. They use 64 bit file offsets and will happily write beyond the 2/4 GB boundary.

But a LabVIEW string is limited to 2^31 elements so you can’t write more than 2GB per write operation.

[altenbach · Accepted solution]

Well, all file IO buffering is done by the OS caching, but I don't think you are talking about that, but are simply interested in any potential size restriction. (To ensure that the data is actually on the disk, you can flush if needed )

The file offset is I64 (i.e. 63 bits, (allowing almost10 exaBytes of data)) and you will run out of disk space way before even putting a dent in that. 😄

Since you seem to write "continuously", you just need to make sure that each portion fits into a LabVIEW datatype, i.e. 2^31 elements which is already guaranteed, since it is a LabVIEW program. Same for reading it back.

For massive data, I recommend to do flat binary, not e.g. any numbers as formatted text, of course.

[Dhruv1140]

Thanks I got it

[Dhruv1140]

Thank You