I know it is impossible die to the insane complexity our hardware and software has. When I calculated the requirements in 2005 the goal was not to be dependent on the electronics and FPGA Jon Elson was making at that time. I agree that it will be probably necessary to buy it from him (or somebody else) at certain point when I will want to move to high resolution at low speed and still be able to achieve very high maximum speed. Interpolation will be sufficient.
But back to what Andreas proposes: I think that interrupt frequency in direct pulse output such as the quadrature one may benefit from interrupt frequency that will be variable withing certain limits. The problem currently is that we have TWO loops - one at ~1kHz for trajectory planner and the other at ~100kHz for pulse output. And we have only one interrupt source and only ONE independent CPU. If there were two CPUs each with its own interrupt source it would be much easier. On Sun, Mar 1, 2009 at 8:45 PM, John Kasunich <jmkasun...@fastmail.fm> wrote: > Jon Elson wrote: >> Mario. wrote: >>> I have the ultimate goal of reaching 2 milion quadrature output >>> changes per second from any of the outputs, even 200 thousand per >>> second is almost good for me. >>> How does your method help me get to the intended goal? I'm talking >>> about parallel port of course. >>> >>> >> It will be totally impossible to make a motherboard parallel port output >> 2 million changes per second. > > Agreed. > >> >> Even getting 200 KHz output with complex code is very unlikely. You >> would need to set the interrupt frequency to 200 KHz = 50 us, > > 200KHz interrupts is a 5uS period, not 50uS. Not happening on any PC. > I think Alex Joni once got the period down to about 6.5uS, just to see > how far he could go. The machine was not very usable at that point. > >> You could set the interrupt frequency to 400 KHz or 25 us, > > 400KHz is 2.5uS, not 25uS. Even more impossible. > > Software generation in a PC at those rates is simply impossible. > Hardware is the way to go. > > Regards, > > John Kasunich > > > > ------------------------------------------------------------------------------ > Open Source Business Conference (OSBC), March 24-25, 2009, San Francisco, CA > -OSBC tackles the biggest issue in open source: Open Sourcing the Enterprise > -Strategies to boost innovation and cut costs with open source participation > -Receive a $600 discount off the registration fee with the source code: SFAD > http://p.sf.net/sfu/XcvMzF8H > _______________________________________________ > Emc-developers mailing list > Emc-developers@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-developers > ------------------------------------------------------------------------------ Open Source Business Conference (OSBC), March 24-25, 2009, San Francisco, CA -OSBC tackles the biggest issue in open source: Open Sourcing the Enterprise -Strategies to boost innovation and cut costs with open source participation -Receive a $600 discount off the registration fee with the source code: SFAD http://p.sf.net/sfu/XcvMzF8H _______________________________________________ Emc-developers mailing list Emc-developers@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-developers
