On Saturday 15 February 2020 06:29:08 N wrote: > > On Friday 14 February 2020 02:01:08 andrew beck wrote: > > > Chris. I'm still learning electronics. Could you expand a bit on > > > this please. > > > > > > Maybe draw a napkin sketch of it. Sorry to be a bit slow on the > > > uptake > > > > I'm not Chris, but the word quadrature means two signals that change > > state like this at a steady speed > > > > ---- ---- ---- ---- ---- logic + > > ____ ____ ____ ____ ____signal A, logic - > > > > ---- ---- ---- ---- ---- logic + > > __ ____ ____ ____ ____ __signal B. logic - > > Very common, very common and if I remember correct RS422 circuits may > be used to decode this signal, schmitt triggered inputs might be good.
That comes std when using the $2 convertor to undifferentiate a balance encoder to a rail to rail ttl signal to be fed to a 5i25. > > ... > > > > This type of encoder signal never skips a count even after millions > > of direction changes. ... > > Well, there is usually plenty of noise in power electronics even with > differential input signals schmitt triggered inputs might be needed. > Checking encoder counts at zero pulse is of course a good idea. That noise drops into the millivolt range if a single bolt ground system is used. Said differently in a condescending tone of voice, if you have more than 100 millivolts of noise anyplace you look with a scope, your ground system system is in need of help, probably a ground loop someplace. Grounding a cable shield at both ends would be a prime candidate. > > And its cheap to build in hardware or software but > > the software version will have a speed limit much slower than the > > hardware version, but even that can work on a smallish mill at up to > > 30 or so inches a minute, with only a parport breakout board driving > > the machines motors. > > The counter in Micro controllers usually have encoder mode for this > purpose, it's cheap though a fast differential receiver may be more > expensive than Micro controller but it's more because they are cheap > and not that many dollars or whatever currency you count. > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) If we desire respect for the law, we must first make the law respectable. - Louis D. Brandeis Genes Web page <http://geneslinuxbox.net:6309/gene> _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
