Re: NI DAQCard-6062E & trigger modes

On Mon, Nov 11, 2002 at 03:00:05PM -0500, do_not.email_me_at_nowhere.org wrote:
> Hi,
> 
> I am looking at the feasibility of using the DAQ card listed above.
> 
> The signal of intereset is aperiodic <100mS in duration every 5-10 Secs>.  
> I would like <ideally> to trigger off of the 100mS "blip" and, whith a 
> combination of pre&posttrigger acquire the whole blip <including onset>.  
> The card's FIFO <8KB> is large enough to store all of the event.

Pretriggering is not supported in Comedi.  The main reason is that
to do it correctly requires a 3-nested-loop equivalent to the
2-nested-loop comedi_command structure.  This is planned for
post-1.0 Comedi.

It's generally not difficult to emulate pretriggering in software,
although with the overhead of an extra analog channel to measure
the triggering signal.



dave...

Received on 2002-11-11Z21:00:52