NI DAQCard-6062 command read/write problems

Hi,

I have the  NI DAQCard-6062  pcmcia card installed on a 1.2 GHz laptop running
Redhat linux with a customized kernel (2.4.18 international kernel with crypto
and
ACPI patches) I'm having several problems that I have not been able to work
though.
Any clues to dealing with any of the following would be greatly appreciated. 

1) When doing command analog I/O (particularly AI but I think I've seen it with
AO
as well)  at high sampling rates (~500 kHz),  the read/write command fails to
return
after writing several secons of data. In other words, the I/O operation works
fine for
short periods of time but then dies after several seconds.

2) I have an application that requires simultaneous command AI and AO (active
sonar
testing). I want to begin recording data (using command mode - read) transmit a
short 
waveform (again using command mode - write) and continue recording for a set
period 
of time while waiting for an echo. Is this possible? Can the device/comedi do
simultaneous
I/O? I found a reference to this problem in the archives from several years ago
but the
conclusion was ambiguous.

3) This problem is related to 2). When my application runs the read command is
issued
followed by the read loop. While the read is in progress, I issue another
comedi_comand
for the AO subdevice which returns with no indication of any problems. However,
writing to the comedi device causes a segmentation fault and the app crashes
(LABVIEW).
Afterwards, the AO subdevice is unuseable. Any attempt to issue comedi_command
or run comedi_calibrate on the AO subdevice fails with a "Device Busy" error.
There
do not appear to be any processes running that are accessing the device, but I
can't even
unload the comedi_modules. (Again, rmmod reports the device is busy)  The only
way
I've found to recover is to reboot the system which aside from being annoying,
slows my
debugging efforts to a crawl. Please tell me there's a better way. I feel like
I'm working
with a Windoze box.

Thanks,

Mike Bird

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Received on 2003-09-19Z16:37:33