1. G Function Description
1.2.31 G70/G71: UNIT SETTING OF INCH/METRIC
SYSTEM
Command form:
G70;
G71;
Description:
G70: inch system
G71: metric system
After change inch/metric system, origin offset value of workpiece
coordinate, tool data, system parameter, and reference point, all of that is
still correct. System will deal the change of unit automatically. After change
inch/metric system, item below will change as follow:
Coordinate, unit of speed
increment JOG unit
MPG JOG unit
Decimal Point Input
When parameter is inputted by decimal point input, will to be the
common measurement unit, mm, inch, sec…etc., if input by whole number,
it will to be the Min unit that system default, m, ms…etc.
example:
decimal point: .
whole number: 
80
    "