NCT Group 2000M Inch/Metric Conversion G20, G21, Specification and Value Range of Coordinate Data

5 The Coordinate Data

N3 Y120

N4 Y180

N5 Y240

N6 Y300

N7 Y360

N8 G15 G0 X100

5.3 Inch/Metric Conversion (G20, G21)

With the appropriate G code programmed, the input data can be specified in metric or inch units. G20: Inch input programming

G21: Metric input programming

At the beginning of the program, the desired input unit has to be selected by specifying the appropriate code. The selected unit will be effective until a command of opposite meaning is issued, i.e., G20 and G21 are modal codes. Their effect will be preserved even after power-off, i.e., the unit prevailing at the time of power-off will be effective after power-on.

The change of the unit will affect the following items:

–Coordinate and compensation data,

–Feed,

–Constant surface speed

–Position, compensation and feed displays.

5.4Specification and Value Range of Coordinate Data

Coordinate data can be specified in 8 decimal digits.

The decimal point will be interpreted as the function of the unit of measure applied:

–X2.134 means 2.134 mm or 2.134 inch,

–B24.36 means 24.36 degrees when address B refers to a rotary axis.

The use of a decimal point is not mandatory.

– X325 means e.g. 325 mm. The leading zeros may be omitted.

– .032=0.032

The trailing zeros may be omitted behind the decimal point.

– 0.320=.32

The control will interpret a number with more decimals defined by the increment system. For example, command X1.23456 will be, when IS-B increment system is selected, interpreted as

–1.235 mm (metric unit),

–1.2346 inch (inch unit).

Accordingly, the input data will be output as rounded values.

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