NI DAQCard 6062E and cmd read lockups

Hi,

I've been working with Labview and the test programs that come with 
comedi/comedilib and am having problems using the command and read 
combinations. Even the test program that comes with comedilib, `cmd`
exhibits the problem described below.

When working at higher data sampling rates (>200,000 Hz), `cmd`/read 
often locks-up during its call to read data from the comedi buffer. The read 
call is entered, but it never returns. I can occasionally collect a few seconds

of data up to the DAQCard's rated speed (500 kHz), but it almost always 
fails for longer data collection times (>5 s).

I'm running a 1.2 GHz Compaq notebook computer with little else running 
in the backround. I recently had an overheating problem with this system 
that forced the CPU to run at a much lower rate. During this period, the 
symptoms described above significantly intensified.

Questions:

 1) Is my notebook too slow to keep-up with the data?
 2) Am I expecting too much from the DAQCard 6062 (it's rated at 500 kHz)?
 3) Why doesn't read return with an error of some sort?

I've tried increasing the read-buffer size using comedi_config but that didn't
seem to help.

Any comments/suggestions would be most welcome.

Thanks,

Mike Bird



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Received on 2003-08-06Z17:51:12