Re: Fastest way to read data out from AD board?

Hello,

  I have also tried to sample and read data by the code adapted from 
cmd.c. But it caused broken pipe error when the sampling rate exceeded 
400kHz. Did you experience the same problem with DAS4020/12?
  I am currently sampling the data in the kernel space. The code is 
attached below. It allows data sampling at over 1 MHz (tested with 
pci-6071e & 6259m). It requires RTAI in addition to COMEDI. Would you 
let me know if it works with DAS4020? I am curious up to what sampling 
rate it can handle data acquisition.

Regards

Assar Westman wrote:
> Hi all
> I have a *PCI-DAS4020/12 *which I have been trying to use in a air 
> warning radar system. What will the fastest way to read data from the 
> card. At the moment I am using the read interface as shown in the 
> cmd.c program, but I wonder if some other mean of reading data out 
> would be faster, maybe mmap or some other comedi software interface I 
> have not found yet. 
>
> I am sampling at 1 MHz and have new data around at a speed of 400 Hz 
> and I need to take as much data as possible and do some pre-analyzis 
> on the data on the same machine, so I really need the maximum transfer 
> speed in this application.
>
> Best regards Assar westman

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Yoshiya Matsuzaka
Dept. of Physiol., Graduate School of Medical Science,
Tohoku Univ.
2-1 Seiryo machi, Aoba ward, Sendai 980-8575, JAPAN
Tel: +81-22-717-8073, Fax: +81-22-717-8077
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