RTAI-COMEDI

Hi everyone

> I am a student from The University of Sheffield (UK), right now I have just
> started my MSc Control Systems project at the Department of Automatic
> Control and Systems Engineering. I am dealing with the problem of obtaining
> data, using a PCI DAS 1602/16 board. In previous works with this card, the
> laboratory made use of the Real Time Windows Target and Simulink softwares
> to run the experiment. But the acquisition data sample rate was to slow
> (approx. 20 kHz) comparing with the 200 kHz that it is possible. I will
> appreciate very much your opinion on the following question: would it be
> possible to achieve this sampling speed by using the combination of
> RTAI/COMEDI with Matlab/Simulink approach?

I was reading this paper

TkDAS: A Data Acquisition System
Using RTLinux, COMEDI, and Tcl/Tk

Kenneth H. Jacker and Joshua T. McKinney
Computer Science Department
Appalachian State University
Boone, NC 28608 USA
fkhj, jtmg_at_cs.appstate.edu

and at the Future Work section they mentioned the next sentences:

"There is also a need to allow sampling rates
higher than that permissible using COMEDI's \sin-
gle sample" mode (currently limited to about 50,000
Hertz). Again, if the data acquisition board sup-
ports it, COMEDI can use its direct memory access
mode to transfer samples from the board to mem-
ory without using central processing unit (CPU) cy-
cles. This can provide sampling rates as high as
1,000,000 Hertz."

My goal is to achieve 200 kHz sample rate ADC to the analog signals coming from
the sensors,

Where can i find more information and documentation about COMEDI DMA mode? Do
you know if this card PCI DAS 1602/16 supports DMA?

Thank you very much for your kind attention

Rufino Bolado-Gomez

Received on 2007-05-09Z20:21:58