Hallo, Sorryto hear of this disaster. The old Siemens way was to lock out the drive if the output of the speed opamp (so including I ) was at the limit for longer than 100msecs. The modern way on difgital servo drives is "trip on loss of communication lasting longer than 2 servo cycles." And a host of trip conditions of course thart the servo knows to detect.
Also there exists a very simple error detection circuit for 8 wire encoders, but the details have escaped me. I would have to look in the archives to find it again. Hardware wise the easiest way is to provide impact absorbers at the end of the travel. 1 or 2 pieces of 30mm thinwalled pipe work wonders. But be sure to test out the pipe you plan to use. It should collapse to +-30% of its length on impact. Cheers, j. On Wed, May 23, 2012 at 7:36 PM, Peter C. Wallace <p...@mesanet.com> wrote: > On Wed, 23 May 2012, Jon Elson wrote: > > > Date: Wed, 23 May 2012 12:13:34 -0500 > > From: Jon Elson <el...@pico-systems.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] Encoder Redundancy? > > > > andy pugh wrote: > >> On 23 May 2012 07:08, Jeshua Lacock <jes...@3dtopo.com> wrote: > >> > >> > >>> I am guessing there is not an easy way to detect this condition, > >>> > >> > >> It should be possible to check if your PID is saturated for more than > >> a second or so. > >> > > But, this still doesn't detect a servo runaway when the Gecko drive is > > started up. > > LinuxCNC is not sending any command to the drive at this point. So, > before > > F2 is pressed, PID output is clamped at zero. > >> Note that I am not sure what amp-fault-in actually does, but it was > >> conveniently available and sounds about right. > >> > > It is a signal provided by some servo amplifiers to indicate they are in > > fault status. > > > > Jon > > Which is a good illustration of the limitations of step/dir servos since > LinuxCNC can't "see" whats happening in the drive, which rules out a lot of > hardware fault mitigation strategies. > > > Peter Wallace > Mesa Electronics > > > > ------------------------------------------------------------------------------ > Live Security Virtual Conference > Exclusive live event will cover all the ways today's security and > threat landscape has changed and how IT managers can respond. Discussions > will include endpoint security, mobile security and the latest in malware > threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
