yes - with rt-preempt you usually get higher jitter. Probably not good for base thread systems. For servo only (with external interface hardware like yours) it will work great.
Peter with mesa has also done some magic with his cards (I don't understand it fully) using a DPLL to help negate jitters affect. You can really see how it lowers the following error.. sam On 3/13/2015 10:51 AM, Jon Elson wrote > On 03/13/2015 09:52 AM, sam sokolik wrote: >> I still cannot believe that it is possible. I have been testing 2.7+ >> uspace for a while now. It defiantly opens up options. >> >> > I just did some comparison tests between rtai and uspace, on > a 2 GHz Pentium 4 > system. I found uspace had a LITTLE bit more jitter on the > servo thread. I got > about +/- 10 us jitter on the encoder position sampling > pulse with my Universal > PWM Controller using rtai. With uspace, it was about +/- 20 > us. Even the > 20 us jitter is only 2% of the 1 ms period. I watched for a > while for outliers, > and did not see any. > > I'm pretty sure I could go up to 2 KHz servo thread with > either RT system with > my boards as well. > > Total time to do the servo thread was about 150 us under > both RT systems, > including using the velocity estimation feature, which > requires reading > 10 more registers from the controller board. > > Jon > > ------------------------------------------------------------------------------ > Dive into the World of Parallel Programming The Go Parallel Website, sponsored > by Intel and developed in partnership with Slashdot Media, is your hub for all > things parallel software development, from weekly thought leadership blogs to > news, videos, case studies, tutorials and more. Take a look and join the > conversation now. http://goparallel.sourceforge.net/ > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > > ------------------------------------------------------------------------------ Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
