G68: Program Coordinate Rotation Mode Start - Mitsubishi Electric MELSEC iQ-R16MTCPU Programming Manual

G68: Program coordinate rotation mode start

Specifies a rotation angle for the coordinate system and performs positioning on the rotated shape.
Code Format
G68
G68 X x
Processing details
• The G68 command specifies a rotation angle for the local coordinate system, and performs positioning on the rotated
shape.
Y
y1
x1
Original local
coordinates
Local coordinates
after rotation
• When G68 command is executed, the mode changes to program coordinate rotation mode.
• The G68 command is modal. It remains in effect until program coordinate rotation mode cancel (G69) is commanded.
• When transitioning to G-code control or resetting, program coordinate rotation is cancelled.
• In the plane selection command (G17, G18, G19), select the command plane. Plane selection cannot be commanded in the
same block as G69 command. When commanded in the same block, a minor error (error code: 1FC3H (details code:
0326H)) occurs. Also, plane selection cannot be commanded during program coordinate rotation mode. When commanded
during program coordinate rotation mode, a minor error (error code: 1FC3H (details code: 0326H)) occurs.
• Program coordinate rotation is enabled on the local coordinate system. The relationship between the rotated coordinate
system and the work coordinate system and basic machine coordinate system is shown below.
Y Y
Work coordinate system 1
Basic machine coordinate system
• The center of rotation coordinates are always commanded in absolute values based on the local coordinate system.
Incremental value command mode (G91) is regarded as absolute values. When the center of rotation coordinates are
omitted, the position where the G68 command was made becomes the center of rotation.
• The coordinates are rotated counterclockwise by the specified rotation angle. The command value for the rotation angle is
in line with the absolute value command mode (G90)/incremental value command mode (G91) modal.
• The setting range for the rotation angle is -359.9999 to 359.9999[degree]. When commands exceed the setting range, the
command is the remainder after dividing the command by 360.0000[degree].
• The rotation angle is modal data. It remains in effect until a new rotation angle is commanded.
• The rotation angle command can be omitted. However, if omitting the rotation angle when using the G68 command for the
first time after transitioning to G-code control, the rotation angle operates at 0[degree].
• When coordinate rotation mode command (G68) is commanded during program coordinate rotation mode, it is processed
as a change for center of rotation coordinates and rotation angle.
Y y R r
Rotation angle
Coordinate command
Rotation angle
Center of
rotation
X
Y
R: Rotation angle
X
Local coordinates
(X, Y)=(0, 0)
X
X
5 G-CODE CONTROL PROGRAMS
5.6 G-Code
5
151