On Sun, 17 Mar 2013, Tom Easterday wrote: > Date: Sun, 17 Mar 2013 15:15:43 -0400 > From: Tom Easterday <tom-...@bgp.nu> > Reply-To: "Enhanced Machine Controller (EMC)" > <emc-users@lists.sourceforge.net> > To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> > Subject: Re: [Emc-users] PC for LinuxCNC with Mesa boards? > > > On Mar 17, 2013, at 1:18 PM, Peter C. Wallace <p...@mesanet.com> wrote: >> Other than EPP issues with with the 7I43 and some PCI parallel cards, I dont >> think there are any serious compatibility issues with PC -->Mesa hardware. >> The real trick is finding current MBs with decent latency. (and that work >> with the now pretty old Ubuntu 10.04) >> >> I'm pretty happy with the ASUS E45M1 PRO (with c6 state and cool&quiet >> turned off in the BIOS) >> >> This gives ~10 usec servo and base thread latencies on a passively cooled MB >> with noticeably better than Atom performance. > > > Peter, > Why does motherboard latency matter if using the Mesa card? I thought one > didn't need a base thread, just a servo thread. I also have wondered if one > even needs the realtime kernel extensions...? > -Tom
Because all the servo (or stepgen feedback) calculations are done based on the nominal servo thread time so if you have a 1.10 ms thread period instead of 1.00 the corrections applied by either the PID loop or the stepgen logic will be incorrect. > > > ------------------------------------------------------------------------------ > Everyone hates slow websites. So do we. > Make your web apps faster with AppDynamics > Download AppDynamics Lite for free today: > http://p.sf.net/sfu/appdyn_d2d_mar > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your (")_(") signature to help him gain world domination. ------------------------------------------------------------------------------ Everyone hates slow websites. So do we. Make your web apps faster with AppDynamics Download AppDynamics Lite for free today: http://p.sf.net/sfu/appdyn_d2d_mar _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
