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
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? regards Andrew On Thu, May 21, 2020 at 1:12 PM andrew beck <andrewbeck0...@gmail.com> wrote: > hey andy thanks for the quick reply. > > I am wired up with differential twisted pairs. > > I have the 24v dc power supply powering all the general clean power needs > on the machine. eg mesa 7i76 card and servo drives logic power. also > powering the servo on pin on the servo drive connector. > > I am still using the same powersupply I have always used. > > also the 5i25 is connected powering the 7i76 spindle encoder power which I > am using (I don't have a external 5v powersupply. > > I checked the voltages between the 24v io and the 5v from 5i25 and they > are within 1.5volts > > what would be the thing to test next? > > regards > > Andrew > > On Thu, May 21, 2020 at 1:03 PM andy pugh <bodge...@gmail.com> wrote: > >> On Thu, 21 May 2020 at 01:47, andrew beck <andrewbeck0...@gmail.com> >> wrote: >> >> > Now all it seems to do is change from 0 to 1 on the count and there is >> not >> > any sense to the numbers changing. it is not counting as it was before. >> >> This is what you see if one of the A or B channels has stopped >> working. You can probably see this with halscope. >> >> What I suspect has happened is that you have added another DC source >> to the mix with a different 0V reference, and that has exceeded the >> common-mode limit of the encoder inputs (this only makes sense if your >> encoder is wired as differential pairs. And jumpered accordingly) >> >> If your encoders are wired single-ended, then it's probably the same >> root cause, and, in fact, it's easier to get this problem single-ended >> (if you _can_ wire as different pairs, then you really should) >> >> If there are terms here that are unfamiliar I am happy to explain further. >> >> -- >> atp >> "A motorcycle is a bicycle with a pandemonium attachment and is >> designed for the especial use of mechanical geniuses, daredevils and >> lunatics." >> — George Fitch, Atlanta Constitution Newspaper, 1912 >> >> >> _______________________________________________ >> 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
