-------- Original-Nachricht -------- > Datum: Fri, 31 Jul 2009 17:15:09 -0400 > Von: Stephen Wille Padnos <spad...@sover.net> > An: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> > Betreff: Re: [Emc-users] Mesa 7i33 encoder inputs and up/down counter mode
> Sebastian Kuzminsky wrote: > > >Gerhard Pircher wrote: > > > > > >>>If your spindle is not reversible you could connect the step line to > >>>either Up or Down, and run it that way. > >>> > >>> > >>Well, it is reversible. Maybe I should build a simple step/dir to > >>quadrature converter. That shouldn't be too hard. > >> > >>Thanks for enlightening me! > >> > >> > >It might be simple to use the Dir line from your spindle as the > >selector to a demux, and send the Step signal to either Up or Down on > >the hm2 encoder input. > > > > > That's a good idea, with a couple of caveats: > > 1) There is no demux component ;) > 2) When someone writes one, they will need to be careful about what > happens to the unused output - there shouldn't be any unexpected > transitions on the "other" output > 3) There could be several counts in the wrong direction since counting > is done in a MHz-speed "thread" in the FPGA and the demux would only be > checked at 1Khz to 10kHz rates. This wouldn't be bad in practice since > the spindle would have to slow down before reversing, but it could also > be a problem if the spindle is more or less still and the dir line > changes out of sunc with the step pulses. The demuxing would be done in hardware (e.g. with a 4x NAND TTL IC to build the demux). Gerhard -- Neu: GMX Doppel-FLAT mit Internet-Flatrate + Telefon-Flatrate für nur 19,99 Euro/mtl.!* http://portal.gmx.net/de/go/dsl02 ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
