
4.REFERENCE POSITION ESTABLISHMENT B-63943EN-1/02
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4.3 AUTOMATIC REFERENCE POSITION RETURN AND
RETURN FROM THE REFERENCE POSITION
Explanation
- Automatic reference position return (G28)
The G28 command positions the tool to the reference position, via the
specified intermediate point, then sets the completion signal for
reference position return (see Section “Manual Reference Position
Return”) to 1.
The reference position must be set in parameter No. 1240 (with the
coordinates specified in the machine coordinate system,) before
issuing the G28 command.
The tool moves to the intermediate point or reference position at the
rapid traverse rate.
One of the following can be selected by LRP (bit 1 of parameter No.
1401) for the tool path to the intermediate point in automatic reference
position return (G28), as with the positioning command (G00).
- Nonlinear interpolation positioning
The tool is positioned with the rapid traverse rate for each axis
separately. The tool path is normally straight.
- Linear interpolation positioning
The tool is positioned within the shortest possible time at a speed
that is not more than the rapid traverse rate for each axis.
Intermediate point
Nonlinear interpolation positioning
Parameter LRP(No1401#1)=0
Start point
Linear interpolation positioning
Parameter LRP(No.1401#1)=1
Nonlinear interpolation
positioning
Reference
position
In this case, nonlinear interpolation positioning is used for the tool
path from the intermediate point to the reference position.
Positioning in the machine coordinate system is used for traversing
from the intermediate point to the reference position by the automatic
reference position return (G28) or positioning in the machine
coordinate system (G53).
Generally, nonlinear interpolation positioning is used for positioning
in the machine coordinate system.