Specifications

Mode Units
This command sets the printer units of measurements. The ^MU
(Mode Units) command works on a field by field basis. Once the
mode units is set, it carries over from field to field until a new mode
units is entered.
The format for the ^MU instruction is:
^MUa
where
^MU = Mode Units
a = Units:
Default: D = Dots
I = Inches
M = Millimeters
Example (ZPL and label output):
Assume 8 dot per millimeter - 203 dot per inch printer.
^MUd^FO100,100^GB1024,128,128^FS
(field based on dots))
^MUm^FO12.5,12.5^GB128,16,16^FS
(field based on millimeters )
^MUi^FO.493,.493^GB5.044,.631,.631^FS
(field based on inches )
296 ZPL II COMMAND REFERENCE
^MU