RTAI and comedi: leaving real time?

Hi list,

Excuse me for sending this message to both the Comedi and the RTAI list,
but I'm not sure where the problem is.

I'm trying to control an NI-DAQ PCI-6024E card with comedi and RTAI. 
I'm running RTAI in periodic mode. When I issue a call to one of the
comedi functions I see the following line in my dmesg:

LXRT CHANGED MODE (SYSCALL, LxrtMode 0), PID = 631

If I understand it correctly it means that LXRT exited real time for a
while to because it detected a Linux system call. Is that right?

Strangely I see this entry in dmesg only the first time I run my
program. Shouldn't it be there every time I run the program? After
unloading and reloading the rtai_lxrt kernel module the entry appears
again the first time I run my program. 

The comedi functions I use in my real time program are:
comedi_dio_bitfield() to clock out some DIO bits and comedi_do_insn() to
send bits to the analog output. 
I thought is was possible to use these comedi functions in real time.

I'm running RTAI version 3.1 on a Slackware 10.1 machine with kernel
2.4.26-adeos (compiled by myself). I'm using comedi version 0.7.69.

Thanks for any help!

Lennart.
-- 
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L.C. Karssen
Department of Physics and Astronomy
Faculty of Science
Utrecht University
Princetonplein 1
3584 CC  Utrecht
The Netherlands

tel.: +31 (0)30-253-2208
fax.: +31 (0)30-253-7468
e-mail: L.C.Karssen_at_phys.uu.nl
www: http://www1.phys.uu.nl/wwwaoud
-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-

Received on 2007-05-13Z11:39:14