hey peter I am using a 5i25 and 7i76 combo. and currently supplying power from the 5i25
so I don't particularly want to make the computer ground the same as everything else lol. it sounds like I need to connect a external 5v powersupply up to the 7i76 and change the jumpers around to suit. and then connect up everything again. I have a 7i89 coming soon and I will wait until then to sort this out I think. I will just disconnect the encoder feedback for now and make some parts. as my servo drives are tuned now. its a bit silly that it only just now failed though. it was working perfectly yesterday. regards Andrew On Thu, May 21, 2020 at 1:46 PM Peter C. Wallace <p...@mesanet.com> wrote: > On Thu, 21 May 2020, andy pugh wrote: > > > Date: Thu, 21 May 2020 02:33:16 +0100 > > From: andy pugh <bodge...@gmail.com> > > 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] mesa 7i76 spindle encoder not counting suddenly > > > > On Thu, 21 May 2020 at 02:22, andrew beck <andrewbeck0...@gmail.com> > wrote: > > >> I read a post you made while ago saying that the 5v and 24v > powersupplies > >> need to be within a certain threshold to work well. or else they need > to > >> be commoned together > > >This is really a question for PCW. I think that they need to be within > >12 (17?) volts to work. > > There should be no substantial common mode voltage. That is the > quadrature source and the 7I76E must have a common ground. > > The input common mode range on the 7I76E encoder input is -7 to +12V > you can easily exceed this (and even damage the reciever chip) > if the source and 7I76E do not have a common grouns > > > >> so if I test between the 7i76 mesa 24 field power ground ( this is the > same > >> power as the servo drive control power) and the logic 0v on 7i76 I > should > >> get close to 0v is that correct? > > >The important thing is that the difference between + and - is a couple > >of volts or so (positive or negative) and in both states the > >difference between each input and 7i76 gnd is <12V (or possibly 17, > >the number is in the manual) > > > -- > atp > "A motorcycle is a bicycle with a pandemonium attachment and is > designed for the especial use of mechanical geniuses, daredevils and > lunatics." > яя George Fitch, Atlanta Constitution Newspaper, 1912 > > > _______________________________________________ > 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. > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
