hey peter I had a look and the unless there is a shorted out pin in the servo drive connector itself I think the wiring is all good.
and I highly doubt the servo drive has problems all I did was connect the 24v back into the servo on pin which is how it has been running for the last ages. anyway how do you recommend commoning the grounds? it is as simple as connecting the field power 0v ground with a wire to the logic power 0v ground? regards Andrew On Thu, May 21, 2020 at 4:26 PM andrew beck <andrewbeck0...@gmail.com> wrote: > 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
