G91: Incremental Value Command - Mitsubishi Electric MELSEC iQ-R16MTCPU Programming Manual

G91: Incremental value command

The coordinate command is executed as an incremental value command.
Code Format
G91
G91 X x
Processing details
• In incremental value mode, the movement is made for the specified value only, with the current position as the start point
(0). Positioning commands set after the execution of the G91 command use the incremental value from the current position.
Ex.
G91 X100. Y100.
Y
150 (150,150)
100
50
Current position (50,50)
0 50 100 150
When current position coordinates are X50,Y50
• Within the same block, a specific address only as an absolute value, or an incremental value can be commanded. The last
executed command in the block remains valid as a modal command.
Ex.
G91 X100. G90 Y100.
Y
150
100
50
Current position (50,50)
0 50 100 150
When current position coordinates are X50,Y50
• The G91 command is modal. It remains in effect until absolute value command mode (G90) is commanded.
• The mode at the G-code control start, or reset can be set in [Motion Control Parameter][G-code Control Parameter][G-
code Control System Parameter]"Modal Initial Setting""Absolute Setting".
Y y Z z
Coordinate command
Y
150
100
50
X
0
When current position coordinates are X80,Y20
(150,100)
X
[Unit: mm]
(180,120)
Current position (80,20)
50 100 150 200
5 G-CODE CONTROL PROGRAMS
X
[Unit: mm]
5.6 G-Code
5
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