Real-time streaming data collection with NI-MIO

I am looking for some help with streaming mode real-time data collection with 
comedi on a PCI-6071E card under Linux (NI-MIO driver).

We are using the card to read in a long stream of EEG data and would like to 
be able to synchronize the data that we are getting from the card with the 
timing of images being displayed on the screen.  When using the streaming 
interface, we find that comedi only gives us blocks of 4096 bytes of samples 
at one time.  Repeated calls to read from the card get zero bytes, until 4096 
bytes are available, and then all 4096 bytes are returned by read.

We are using 64 channels and would like to be able to access each 128 byte 
chunk as the card reads it in.  We have played with comedi's buffering 
functions, but had no success.  Does anyone have any advice for us?

Any help is greatly appreciated.  Thanks so much.

-Josh Jacobs

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Josh Jacobs
Josh_at_mit.edu

Received on 2003-07-07Z21:33:18