John Kasunich wrote: > The scope trace shows that the the home input to the motion controller > is true during the first slope - that means EMC thinks it is already > on the switch, and is trying to get off of it. > > From the HAL file: > > # Connect limit/home switch outputs to motion controller. > newsig Xminlim bit > newsig Xmaxlim bit > newsig Xhome bit > linksp Xminlim <= m5i20.0.in-00-not > linksp Xminlim => axis.0.neg-lim-sw-in > linksp Xmaxlim <= m5i20.0.in-01-not > linksp Xmaxlim => axis.0.pos-lim-sw-in > linksp Xhome <= m5i20.0.in-00 > linksp Xhome => axis.0.home-sw-in > > Note that the limit switch signal is connected to the -not pin. That's > because your switches are active low. But the home signal is connected > to the regular pin, not the -not one. So EMC is confused about the > polarity of your home switch. > > The solution is to connect EMC's home input AND its negative limit input > both to the -not driver pin. > > However, you can't connect two signals (Xminlim and Xhome) to one pin. > You can connect two or more pins to one signal. I'd do it like this: > > # Connect limit/home switch outputs to motion controller. > newsig Xminlim-and-home bit > newsig Xmaxlim bit > linksp Xminlim-and-home <= m5i20.0.in-00-not > linksp Xminlim-and-home => axis.0.neg-lim-sw-in > linksp Xminlim-and-home => axis.0.home-sw-in > linksp Xmaxlim <= m5i20.0.in-01-not > linksp Xmaxlim => axis.0.pos-lim-sw-in > > Since you are homing on the negative end of the axis, SEARCH_VEL must be > negative. If you also make LATCH_VEL negative, it will home on the > first index pulse outside the limit switch, which is probably not what > you want. Make LATCH_VEL positive. Then the homing process will be: > > 1) negative slope at SEARCH_VEL until you hit the switch > 2) positive slope at LATCH_VEL until you get off the switch > 3) continue at the same positive slope until you hit the index > 4) done > > Regards, > > John Kasunich > Thank you very much for your detailed reply. I've applied your suggestions, homing works well and I've learnt some more!
Many thanks, Richard ------------------------------------------------------------------------- This SF.net email is sponsored by: Splunk Inc. Still grepping through log files to find problems? Stop. Now Search log events and configuration files using AJAX and a browser. Download your FREE copy of Splunk now >> http://get.splunk.com/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
