Need to speed up while loop

[pincpanter]

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@cstorey  ha scritto:

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@pincpanter wrote:

I'm not really familiar with interfacing oscilloscopes, so my question may not be relevant.

How many bytes do you actually receive? 999999?

If it's less, the full VISA timeout will elapse before the VISA Read terminates. Default VISA timeouts are typically long.

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That's not correct, that 999999 is just a memory buffer allocation size for the read, not a number of bytes to read.  It does not affect VISA timeout.  

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VISA Read Details

This function might return less than the number of bytes requested if the function reaches the end of the buffer, reaches a termination character, or if a timeout occurs. The output error cluster indicates if a timeout has occurred.

Well I did not say that that number "affects VISA timeout". But reading the help better I understand - although not very clearly stated - that there is a receiving buffer size which is different from the number of bytes requested.

The help of the Set I/O Buffer Size function states "If you do not call this function, the buffer size depends on both VISA and the operating system configuration". I don't know the actual size of this buffer, but I thonk it's unlikely to be of the order of than 1 Mb. In that case the actual number of bytes received should always be much less than 999999.