Originally Posted by
PixMan
According to the Fanuc manual I'm looking at right now, #2601 is the system variable for "G54 workpiece zero point offset value, 2nd axis". If you were to get into the 9000-series macro program that is run with the first macro in your program (I think it's 9810, not sure), you'd see that it uses that value which you'd input by virtue of the "#2601 = -xxxx" that you enter. The control likely takes that value, opens the collet, moves the Z axis to that position and executes a "G50 Zxxxx" to begin running the parts.