On Wed, 5 Jun 2002, Miguel Saiz Arnedo wrote: > > Hello. > > I installed RTLinux on my AMDk6 430 MHZ with 128 Mb RAM and up to now I've just > been probing with the example programs. > I have tried the hello.c with various thread periods and observed that when I > try periods of less than 10us my system crashes. Is this a normal limit? Is it > a > hardware limit or is it an RTLinux limit? > If I can't schedule periodic threads with less than 10us period that will mean > that if the thread is used to aquire samples from a DAQ board I will have a > 100KHz sampling rate limit, which I find a bit low for my needs.Is it possible > to achieve higher sampling rates with RTLinux?
You need to set the card to acquire data at 100 Khz into a fifo (a buffer on the card) and then transfer data out of that buffer when it is half full. Generally that means that the card will raise an interrupt on fifo half full, which should then cause and interrupt service routine to transfer the data. All of the data acquisition cards that I know of have this ability, but you have to have a driver that works with rt-linux (see the comedi package, for example). Generally, getting one sample at a time is not possible at high acquisition rates as far as I know. Loren -- [rtl] --- To unsubscribe: echo "unsubscribe rtl" | mail [EMAIL PROTECTED] OR echo "unsubscribe rtl <Your_email>" | mail [EMAIL PROTECTED] -- For more information on Real-Time Linux see: http://www.rtlinux.org/
