Using NI-USB 6009 daq board with rtai

[Donato Azevedo]

Mr Paul,

On 10/22/07, Paul <paul_c at tuxcnc.org> wrote:
>
> Hi Donato
>
> On Monday 22 October 2007 12:29, Donato Azevedo wrote:
> > I work on a college lab that is trying to port some qnx applications
> > to Linux+RTAI. We have a NI-USB 6009 multifunction DAQ and I installed
> > NI's DAQmx-base driver. I'd like to know if I can use this driver's
> > functions on a hard real time task (be it user space or kernel space)
> > within RTAI. I read somewhere that this driver uses ioctl for some
> > purpose and that, being ioctl a system call, I wouldn't be able to get
> > hard real time performance neither in user nor kernel space.
>
> Looking at the specs, it is a USB device - You will not get hard realtime
> performomance out of this device within an RTAI environment. That said, there
> is a USB4RT project out there that appeared to provide a similar level of
> performance to RTnet (realtime ethernet project), but as far as I'm aware,
> the project is dormant.
>
> BTW Couldn't find any Linux driver for the USB-6009...

Well, those are bad news to me...
Anyway, considering I do not want strict HRT, is there a way for me to
measure the maximum latencies or jitter I would get by using the daq
on an SRT application?

The intended use is for temperature process control, so the time
constants are real big (tens of seconds or maybe even minutes).

ps: What is the right way to reply to messages on this list? Should I
send the responses only to the author? Only to the list? Or both?

Thanks for your kindness and attention,
--
Donato Azevedo Vitelli
Control and Automation UnderGrad
UFMG - Brazil