On Sat, 12 Dec 2015, John Alexander Stewart wrote: > Date: Sat, 12 Dec 2015 13:46:58 -0500 > From: John Alexander Stewart <[email protected]> > Reply-To: "Enhanced Machine Controller (EMC)" > <[email protected]> > To: "Enhanced Machine Controller (EMC)" <[email protected]> > Subject: Re: [Emc-users] Z axis stepper gradually losing position > > I had X issues - observable on a long job of engraving. Job came out > slightly not square! > > 5I25 to a Gecko G540 - as mentioned above, inverting the polarity of the > signal(s) fixed it - I was pushing the Gecko G540 slightly too fast. Only > one input of the XYZA showed the symptom. > > The machine has been rock stable since. > > I'd have to go through my backup files and/or notes to see exactly what > signal was inverted. > > May I suggest doubling pulse lengths, and seeing if that helps? Give the > drivers time to settle into a known state? > > Good luck - John.
If the step pulse is inverted you are likely to violate the direction hold time As far as I can tell the G540 timings are based on 5V signals The 5I25 has 3.3V signals when driving a G540 so timings need to be relaxed. You can drive 5V signals with the 5I25 in open drain mode but only on drives that have differential or common anode OPTO coupler inputs with the + input(s) tied to 5V ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
