
B-63942EN/02 NC FUNCTION 1.CONTROLLED AXIS
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1.28 INCH/METRIC CONVERSION
Either inch or metric input (least input increment) can be selected by
G code.
Format
G20 ; Inch input
G21 ; Metric input
Explanation
This G code must be specified in an independent block before setting
the coordinate system at the beginning of the program. Do not specify
this G code in the middle of a program.
Moreover, inch/metric conversion is possible in setting data setting.
After the G code for inch/metric conversion is specified, the unit of
input data is switched to the least inch or metric input increment of
increment system. The unit of data input for degrees remains
unchanged. The unit systems for the following values are changed
after inch/metric conversion:
• Feedrate commanded by F code
• Positional command
• Workpiece origin offset value
• Tool compensation value
• Unit of scale for manual pulse generator
• Movement distance in incremental feed
• Some parameters
When the power is turned on, the G code is the same as that held
before the power was turned off.