Hi all...gpdc the newbie back again....my machine, a MiniTech/hybrid (for productionization) using Gecko's & running our beloved (and I do mean that affectionatley!) Mach3 on a duelly/XP platform,presented me with a problem that, as I think back thru the development of this project, has been an issue right along....when jogging, it gains and/or looses steps, ONLY when jogging....haven't determined as yet if it's always a gain or always a loss, and the evidence is the mismatch between the DRO read back & where I KNOW the cutter/spindle to be....this problem is seen in all (3) axis', is random & a jog speed reduction to 75% didn't help....so, oh smart people of the Mach persuasion, what's up?
 Hood: if you should read this, somewhere around here I've seen where you're in Scotland...do you know any of the guys along the coast who are making their own electrical power with windmills they build?...I've ALWAYS had it in the back of my mind that Mach driven CNC is the be-all/end all  problem fix to precision placement of the super magnets they use into precision pockets, be it into wood, aluminum or whatever....just wondering aloud...

 Again, thanks all for any/all replies to my problem....gpdc

GPDC,
   I have sent you a personal message.

Brett

Brett...thanks for the help yesterday afternoon....so...what I found out was this: absoluetly no skipped or gained steps in jog...indicators don't lie (generally!!)
    What does happen is this:  intrusion into LC = killed motor drives but program continues to run (hello servo's!)
                                          "cycle stop" button input = both program and motors are stopped & will continue on after "cycle start"...but no spindle...and that depends, of course,on where in the program I stopped it (before or after an M3)...is there some way, after the cycle stop input to turn the spindle back on?...hmmm... a magic OEM code or keyboard input or other means I could emulate off the IPAC,interface thru a PLC (or not) or ??
                                          "E" Stop input= this button is detented in, and is wired in series with the "E" stop in the MiniTech motor drive box,as is the LC ...all three (the LC & both "E" stops) are wired NC & the operators' console "E"stop has a second set of contacts (wired NO) that send the ` character
 (which is a"reset") to Mach....so when that "E" stop is hit, the motor drives AND Mach stop, but I saw (on my indicator) a discrepency between it and the DRO's
  So, the bottom line to all this is I placarded the machine to tell the operator that after ANY power interruption, LC intrusion, cycle stop, "E" stop actuation or other, to do a "ref aal home" (auto 0 in effect) & restart the program from the beginning....we'll have to wait & see how that works out, of course (the machine left here for the customers today), but methinks it's a non-issue & problem solved....a little messy perhaps, but solved nevertheless.