Finally got help from sourceforge with my email troubles - after 3 months of waiting for a response.
This homing sequence is a hot topic for me. We wrote a custom homing configuration that works well, but unfortunately it doesn't work the the PRU step generator. >> Simply give the same homing sequence number to each side. This wouldn't work unless you actually assigned a separate joint to each motor and programmed your g-code accordingly. It needs to be simpler than that. What our custom config does is intercepts the step signal after the switch on that side is triggered and waits for the other side to catch up. Then once the other side is triggered, it starts allowing the step signal to pass back out to both sides. Here is the code: # x-axis setp stepgen.0.position-scale [AXIS_0]SCALE setp stepgen.0.steplen 1 setp stepgen.0.stepspace 1 setp stepgen.0.dirhold 35000 setp stepgen.0.dirsetup 35000 setp stepgen.0.maxaccel [AXIS_0]STEPGEN_MAXACCEL net xpos-cmd axis.0.motor-pos-cmd => stepgen.0.position-cmd net xpos-fb stepgen.0.position-fb => axis.0.motor-pos-fb net xstep <= stepgen.0.step net xdir <= stepgen.0.dir net xenable axis.0.amp-enable-out => stepgen.0.enable # y-axis setp stepgen.1.position-scale [AXIS_1]SCALE setp stepgen.1.steplen 1 setp stepgen.1.stepspace 1 setp stepgen.1.dirhold 35000 setp stepgen.1.dirsetup 35000 setp stepgen.1.maxaccel [AXIS_1]STEPGEN_MAXACCEL net ypos-cmd axis.1.motor-pos-cmd => stepgen.1.position-cmd net ypos-fb stepgen.1.position-fb => axis.1.motor-pos-fb net ystep <= stepgen.1.step net ydir <= stepgen.1.dir net yenable axis.1.amp-enable-out => stepgen.1.enable # z-axis setp stepgen.2.position-scale [AXIS_2]SCALE setp stepgen.2.steplen 1 setp stepgen.2.stepspace 0 setp stepgen.2.dirhold 35000 setp stepgen.2.dirsetup 35000 setp stepgen.2.maxaccel [AXIS_2]STEPGEN_MAXACCEL net zpos-cmd axis.2.motor-pos-cmd => stepgen.2.position-cmd net zpos-fb stepgen.2.position-fb => axis.2.motor-pos-fb net zstep <= stepgen.2.step net zdir <= stepgen.2.dir net zenable axis.2.amp-enable-out => stepgen.2.enable # set all of the step signals to reset #setp parport.0.pin-02-out-reset 1 #setp parport.0.pin-04-out-reset 1 #setp parport.0.pin-06-out-reset 1 #setp parport.0.pin-08-out-reset 1 # invert a couple of direction signals setp parport.0.pin-03-out-invert 1 setp parport.0.pin-05-out-invert 1 setp parport.0.pin-07-out-invert 1 setp parport.0.pin-09-out-invert 1 # debounce the y-axis switches and connect them to signals net switches-y1-raw <= parport.0.pin-11-in net switches-y1-raw => debounce.0.0.in net switches-y1 <= debounce.0.0.out net switches-y2-raw <= parport.0.pin-12-in net switches-y2-raw => debounce.0.1.in net switches-y2 <= debounce.0.1.out setp debounce.0.delay 10 # join the home switch signals so that both switches have to be closed to trigger a home position net switches-y1 => and2.0.in0 net switches-y2 => and2.0.in1 net home-y <= and2.0.out net home-y => axis.1.home-sw-in # we will need the inverse of the home switch signals for our logic, so run them through not gates net switches-y1 => not.0.in net switches-y1-inv <= not.0.out net switches-y2 => not.1.in net switches-y2-inv <= not.1.out # we will need the inverse of the direction signals for our logic, so run it through a not gate net ydir => not.2.in net ydir-inv => not.2.out # we need to determine if the home switch for each motor is tripped while the direction line is # moving the motor towards the switch # for both y-axis motors, we will prevent the step signal from passing to the motor # if the motor is moving towards the switch and the switch is tripped # so "or" the inverted direction signals and the inverted home switches net ydir => and2.3.in0 net switches-y1 => and2.3.in1 net doh1 <= and2.3.out net doh1 => not.3.in net doh1-inv => not.3.out net ydir => and2.4.in0 net switches-y2 => and2.4.in1 net doh2 <= and2.4.out net doh2 => not.4.in net doh2-inv => not.4.out # if the step generator is trying to send a step (ystep signal) and either the motor is moving # away from the switch or the switch is not tripped, then pass the step signal to the motor net ystep and2.1.in0 net doh1-inv and2.1.in1 net ystep1 and2.1.out net ystep and2.2.in0 net doh2-inv and2.2.in1 net ystep2 and2.2.out # connect our step and direction signals to the output pins net xstep => parport.0.pin-02-out net xdir => parport.0.pin-03-out net ystep1 => parport.0.pin-04-out net ystep2 => parport.0.pin-08-out net ydir => parport.0.pin-05-out net ydir => parport.0.pin-09-out net zstep => parport.0.pin-06-out net zdir => parport.0.pin-07-out # we are using combined home and limit switches # if either switch trips while the homing sequence is not running, then triggered a negative # limit switch fault net switches-y1 => or2.2.in0 net switches-y2 => or2.2.in1 net limit-y <= or2.2.out net limit-y => axis.1.neg-lim-sw-in net limit-y => axis.1.pos-lim-sw-in net switches-x-raw => debounce.1.0.in net switches-x <= debounce.1.0.out net switches-x => axis.0.home-sw-in net switches-x => axis.0.neg-lim-sw-in net switches-x => axis.0.pos-lim-sw-in net switches-z-raw <= parport.0.pin-13-in net switches-z-raw => debounce.1.1.in net switches-z <= debounce.1.1.out net switches-z => axis.2.home-sw-in net switches-z => axis.2.pos-lim-sw-in# set up the other home and limit switches net switches-x-raw <= parport.0.pin-10-in >Len On 1/3/2014 4:45 AM, andy pugh wrote: > On 3 January 2014 02:05, Josiah Morgan <josiahmor...@gmail.com> wrote: > >> does anyone have a script written for homing in this scenario? > If the gantry can survive a momentary out-of-square then you may find > that nothing special needs to be done. Simply give the same homing > sequence number to each side. > > The problem here is that when one side id searching for the latch the > other side might be backing off prior to searching for the latch, so > the two sides might end up moving in opposite directions. > > I have wondered if the homing behaviour should be to not move any > joint on to the next homing stage until all joints with the same > homing sequence number have completed the prior stage, but then it > gets a bit more complicated if you need to consider questions like > whether the first joint to find the limit should continue in the same > direction or should stop. (I think perhaps the answer is "stop" but > then it is changing state without waiting, and my simple scenario no > longer holds. > > If you simply use the existing home behaviour with a shared sequence > number then the gantry will only actually be squared at the end of the > final home move. Up to that point the out-of-square might even be > worse. You certainly want the final move from latch to home position > to be as short as possible. > -- Len Shelton Applications Engineer PROBOTIX 8800-B N. Industrial Rd. Peoria, IL. 61615 Email: l...@probotix.com Phone: (309) 691-2643 ------------------------------------------------------------------------------ Rapidly troubleshoot problems before they affect your business. Most IT organizations don't have a clear picture of how application performance affects their revenue. With AppDynamics, you get 100% visibility into your Java,.NET, & PHP application. Start your 15-day FREE TRIAL of AppDynamics Pro! http://pubads.g.doubleclick.net/gampad/clk?id=84349831&iu=/4140/ostg.clktrk _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
