
7. COORDINATE VALUE AND
DIMENSION B–63682EN/01
NC FUNCTION
54
Conversion of inch and metric input can be commanded by the G code
command.
G20 : Inch input
G21 : Metric input
Whether the output is in inch system or metric system is parameter-set
when the machine is installed.
Command G20, G21 at the head of the program.
Inch/metric conversation can also be done by MDI setting.
The contents of setting data differs depending on whether G20 or G21 is
commanded.
Numerals can be input with decimal points. Decimal points can be used
basically in numerals with units of distance, speed, and angle. The
position of the decimal point is at the mm, inch, deg position.
There are two types of decimal point notation: calculator–type notation
and standard notation.
When calculator–type decimal notation is used, a value without decimal
point is considered to be specified in millimeters, inch or deg. When
standard decimal notation is used, such a value is considered to be
specified in least input increments.
Use parameters to select input method; whether to input by pocket
calculator type input, or by the usual decimal point input.
Values can be specified both with and without decimal point in a single
program.
Program command
Pocket calculator type
decimal point
programming
Usual decimal point
programming
X1000
Command value without
decimal point
1000mm
Unit : mm
1mm
Unit : Least input incre-
ment (0.001 mm)
X1000.0
Command value with
decimal point
1000mm
Unit : mm
1000mm
Unit : mm
A linear axis refers to an axis moving linearly, and for it values are
specified in mm or inches.
A rotation axis refers to a rotating axis, and for it values are specified in
degrees.
For rotation axes, note the following:
D Inch-metric switching is not performed.
D The machine coordinate system is always normalized to the range
from 0° to 360°.
7.2
INCH/METRIC
CONVERSION
(G20, G21)
7.3
DECIMAL POINT
INPUT/POCKET
CALCULATOR TYPE
DECIMAL POINT
INPUT
7.4
LINEAR AXIS AND
ROTATION AXIS