On Fri, 23 Oct 2009, Michael Haberler wrote: > Date: Fri, 23 Oct 2009 18:56:30 +0200 > From: Michael Haberler <mai...@mah.priv.at> > 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] threading Z oscillation depends on encoder PPR > > I concur that having position-interpolated in the hardware drivers > would be most valuable (hm2 for me, but missing as well) > > since Xmas is forthcoming.. could we have x1-mode as well in the > hardware drivers? > > I am aware of the consequences wrt resolution BUT: x4-mode only works > well if the encoder is close to 50% duty cycle and 90degrees phase > shift - if not x1-mode gives a much more stable position signal > > I can come up with a plot of my crappy encoder to make the point.. ok, > of course the real answer is "better workmanship or a better decoder"; > but again here encoder.9 is superior to the hw encoders > > -Michael
HostMot2 supports X1 mode, and with velocity estimation, postition extrapolation should be somewhat better that the software encoder since its velocity estimate timestamp has more resolution. (When position extrapolation get added) > > Am 23.10.2009 um 18:23 schrieb Jon Elson: > >> Andy Pugh wrote: >>> Perhaps I should have elaborated further. What I was saying is that >>> if >>> the hardware encoder and driver does not offer an interpolated >>> position every servo cycle and the encoder pulse rate is low enough >>> to >>> have multiple servo threads per encoder count, then EMC will see a >>> stationary spindle with the hardware encoder. This might cause the >>> problems we are seeing. >>> >>> In that situation the software encoder, which does offer >>> position-interpolated, is paradoxically superior. >>> >> Yup, now I see your point. Well, I have added the firmware to my PWM >> controller >> for the timestamp registers, but haven't written the code in the >> driver >> to do the calculations. >> One thing that makes it more complicated is when the count is reset on >> the index pulse >> (which you do for a spindle at the start of a threading cycle) the >> velocity calculation needs >> to adjust for that. >> >> Jon >> >> >> ------------------------------------------------------------------------------ >> Come build with us! The BlackBerry(R) Developer Conference in SF, CA >> is the only developer event you need to attend this year. Jumpstart >> your >> developing skills, take BlackBerry mobile applications to market and >> stay >> ahead of the curve. Join us from November 9 - 12, 2009. Register now! >> http://p.sf.net/sfu/devconference >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users > > > ------------------------------------------------------------------------------ > Come build with us! The BlackBerry(R) Developer Conference in SF, CA > is the only developer event you need to attend this year. Jumpstart your > developing skills, take BlackBerry mobile applications to market and stay > ahead of the curve. Join us from November 9 - 12, 2009. Register now! > http://p.sf.net/sfu/devconference > _______________________________________________ > 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. ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! http://p.sf.net/sfu/devconference _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
