the 24v common is currently not connected to the frame ground. It is floating. well the meanwell powersupply has a ground terminal on the input side that is connected to machine ground. but the output side is completely unconnected eg the 24 v and 0v are floating
I will double check the wiring and check if there is a problem On Thu, May 21, 2020 at 4:22 PM Peter C. Wallace <p...@mesanet.com> wrote: > On Thu, 21 May 2020, andrew beck wrote: > > > Date: Thu, 21 May 2020 15:53:45 +1200 > > From: andrew beck <andrewbeck0...@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 > > > > hey PCW and andy > > > > I just checked the mpg with a multimeter. > > > > I had my brother jogging .005mm at a time to try and catch the encoder > > pulses. > > > > when measuring between the B and /B pulses I could measure 2.5 volts when > > the encoder triggered. > > > > I could not measure any voltage at any time through the A and /A > channels. > > > > Broken wire or connecoto problem? > > > PCW how do I common the 5v and 24v grounds together on the 7i76? > > > > I saw this sheet here for the 7i76E that seems to show that the 7i76E > only > > needs 24v and makes its own 5v if you set the jumpers right. (is the > 7i76 > > also the same?) that would make life really easy > > No its normally suggested to have the 7I76 use FPGA power > > > > > [image: image.png] > > > > If I do have to use a separate 5v powersupply eg 5i25 for now can I just > > connect a wire between 24v ground and a unused logic 0v ground pin on a > > step gen port or something? Or should I do something more elegant > > > I would check to see if the 24V common is already connected to frame ground > if it is you should be OK > > > regards > > > > Andrew > > > > On Thu, May 21, 2020 at 3:19 PM andrew beck <andrewbeck0...@gmail.com> > > wrote: > > > >> hey peter I will check that now before I put the machine together > >> again without the encoder config to make parts again > >> > >> > >> > >> > >> > >> On Thu, May 21, 2020 at 3:05 PM Peter C. Wallace <p...@mesanet.com> > wrote: > >> > >>> On Thu, 21 May 2020, andrew beck wrote: > >>> > >>>> Date: Thu, 21 May 2020 14:05:02 +1200 > >>>> From: andrew beck <andrewbeck0...@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 > >>>> > >>>> 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. > >>>> > >>> > >>> Except the the computer ground is frame ground and the common for the > >>> servo > >>> drive quadrature outputs should also be returned to frame ground > >>> > >>>> 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. > >>> > >>> That will not change anything ground related > >>>> > >>>> 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 > >>> > >>> Do you have valid differential signals across the A /A and B /B pairs? > >>> > >>> ( >2 V absolute across the pins, that is more positive than +2V or > more > >>> negative than -2V ) > >>> > >>> Thats would be the most diagnostic test > >>> > >>> > >>> 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." > >>>> яяяяяяяя 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 > >>> > >>> 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 > >>> > >> > > > > 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
