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Maximum achievable USB transfer rate

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Maximum achievable USB transfer rate

Postby ttzoltan » Wed Nov 17, 2010 6:02 am

We need to take a single-shot capture and transfer the contents of the entire acquisition buffer to the PC via USB 2.0.
1. What is the maximum achievable transfer rate using the ps5000.dll API? (application written in C)
2. Is there any difference in USB transfer rate among the various Picoscope series: 3200, 5200, 6400, 9600 ?
Thanks in advance for your answers. :)
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Re: Maximum achievable USB transfer rate

Postby ziko » Mon Nov 22, 2010 1:00 pm

Hi this article will help in explaining the transfer rates:

kb/kbfiles/PicoScopeUSBStreaming.pdf

The 4000,5000 and 6000 (even the 2203/04/05) can stream data very fast depending on your PC and overheads, the 9000 does not stream as it is not a normal Oscilloscope rather a Sampling Scope. The 320Xs stream at about 1kS/s, whilst the 3224/3424/3425 can stream at about 1MS/s.

I hope this helps.
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Re: Maximum achievable USB transfer rate

Postby ttzoltan » Thu Dec 02, 2010 5:45 am

Thanks for your reply. The appnote you referred me to was very informative. :)

I am evaluating a PS5203 now, and the USB transfer rate seems good except that every sample is transferred as 16 bits. Since the low bytes are always 0 (the scope has an 8-bit ADC), this is a mere waste of USB bandwidth. :cry:

Is there a way to transfer just the raw 8-bit samples from the scope?
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Re: Maximum achievable USB transfer rate

Postby Chris » Fri Dec 03, 2010 2:24 pm

The raw data from the scope that gets sent over USB is 8 bit data.

It is scaled to 16 bit by the driver to enable oversampling.
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