Hood
Your not misunderstanding me Z max is at the top of the travel and Z min is at the bottom. Imagine you have got a long tool in the spindle like 200mm long, you then need to have at work offset of at least -200mm so you can go to Z 0. With the current soft limit warnings if you put a work offset in larger than your softlimits you get a warning but it should take the tool offset into consideration as well and not give you a warning.
What the G code does:
Set G54 Z offset to -200 & T3 to +200, this is presuming your soft limits in Z are roughly from 0.0mm to -127.0mm, then run this.
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G21 This puts Mach into metric
G0G17G40G49G80G90 Rapid, XYplane, cancel cutter comp, cancel tool offset, cancel caned cycles, absolute
T3M6 Tool 3, tool change
G0G54G90X0.Y0. Rapid, G54 offsets, absolute
G43H3Z-1. Use tool offset go to Z-1.0 This should move your machine to Z-1.0 in machine coordinates -200+200-1=-1
G1Z-10.F1000. Feed to Z-10 at 1000mm/min
M30
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Cheers
Chris