Andy, you are correct it is related to using index. Homing works fine if I don't use index. The encoder reset makes sense as to why it CAN happen (but shouldn't be). Is this just a bug? I would try to home a second time but as Todd says, I can't clear the error. Linuxcnc shuts off when it happens and pressing on just immediately faults again. I have to exit and restart it.
-Tom > On Jun 20, 2017, at 8:13 AM, Todd Zuercher <zuerc...@embarqmail.com> wrote: > > > ----- Original Message ----- >> From: "andy pugh" <bodge...@gmail.com> >> To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> >> Sent: Tuesday, June 20, 2017 4:27:46 AM >> Subject: Re: [Emc-users] following error only while homing >> >>> On 20 June 2017 at 03:51, <tom-...@bgp.nu> wrote: >>> >>> Why would I get a following error only while homing >> >> >> I think it is probably because you are using HOME_USE_INDEX (which >> will >> zero the encoder at the index pulse) and feeding the encoder feedback >> back >> into LinuxCNC. >> >> Now, this is perfectly normal, and with a servo / pid machine the >> system >> knows to ignore the f-error immediately after an encoder reset. What >> is >> puzzling me here is why it isn't working in this case. I think it is >> something to do with the fact that your system is set up for >> open-loop step >> position control but has encoder feedback. However I can't >> immediately see >> why this makes a difference. >> >> I imagine that if you press the home button again it will home Z >> seamlessly, and then f-error homing the next axis. >> >> >> -- >> atp > > Andy, > > I wish that were true. For some reason my analog servo machine trips up and > sets a following error on an axis about 25% of the time when trying to home > to index for the first time after turning on LInuxcnc. (Almost every time > since it is a 4 axis machine.) But the alarm is easily cleared, and it > always homes fine the 2nd try. I have never been able to figure out why, and > no one else seems to have been able to replicate the problem. > > His problem sounds different since he says can't clear the alarm. > > My other machine with step/dir servos, doesn't have encoder index to home to. > But it does home fine without ever setting following errors. > > ------------------------------------------------------------------------------ > Check out the vibrant tech community on one of the world's most > engaging tech sites, Slashdot.org! http://sdm.link/slashdot > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
