Quoth andy pugh..... >On 3 October 2013 13:22, Russell Brown <russ...@lls.lls.com> wrote: >> So. Why are the absolute values in the INI different to the ones in the >> HAL file? There's obviously some magic going on here :-) > >However, if the axis limits are exactly the same as the stepgen limits >then the stepgen has no "overhead" to work with, and trouble ensues. >So the stepgen limits on velocity and accel need to be a shade higher >than the axis limits.
That's the kiddy. Have a cigar Mr Pugh. I misinterpreted Peter Wallace's earlier comment in this thread when he said: >>>One thing that is required is that the per axis stepgen maxaccel >>>parameter be set to about 20% greater than the machine maxaccel for >>>that axis. My befuddled brayne though he was talking about the INI STEPGEN_MAXACCEL setting. Too many settings with the same name! However even that's not the full solution. >it used to be that the stepgen limits could be set to zero and the >stepgen would simply do as it was told. I don't recall what changed >there, or why it changed. In http://www.linuxcnc.org/docs/devel/html/drivers/hostmot2.html (13.2 Parameters maxaccel) is still says you can set it to 0. >It is perfectly OK to add things to the INI file and reference them in >your HAL file if you want to. It would be nicer if pncconf did this >for you for those parameters, though. Can the code that expands the references in the INI file do multiplication then? It would need to be able to do this to maintain a working reference so you end up with: setp hm2_5i25.0.stepgen.00.maxaccel [AXIS_0]MAX_ACCELERATION * 1.2 setp hm2_5i25.0.stepgen.00.maxvel [AXIS_0]MAX_VELOCITY * 1.2 Because taking on board both your and Peter's comments, setting *both* the hm2_5i25.0.stepgen.XX.maxaccel and hm2_5i25.0.stepgen.XX.maxvel to the values in the INI file +20% makes everything work. Just changing maxaccel or just maxvel doesn't fix the 'Following errors' problem. Ta to everyone for their comments. I'll post sommat on the Forum for future reference. -- Regards, Russell -------------------------------------------------------------------- | Russell Brown | MAIL: russ...@lls.com PHONE: 01780 471800 | | Lady Lodge Systems | WWW Work: http://www.lls.com | | Peterborough, England | WWW Play: http://www.ruffle.me.uk | -------------------------------------------------------------------- ------------------------------------------------------------------------------ October Webinars: Code for Performance Free Intel webinars can help you accelerate application performance. Explore tips for MPI, OpenMP, advanced profiling, and more. Get the most from the latest Intel processors and coprocessors. See abstracts and register > http://pubads.g.doubleclick.net/gampad/clk?id=60134791&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
