44
Absolute and Incremental
G90 and G91
Y
X
5
10
15
20
(mm)
0
5
10
15
y=7000
(Increase in Y)
x=15000
(Increase in X)
(4000, 5000)
(19000, 12000)
Y
X
5
10
15
20
(mm)
0
5
10
15
(19000, 12000)
(4000, 5000)
G90
G00X4000Y5000
G01X19000Y12000
G90
G00X4000Y5000
G91
G01X15000Y7000
Format
G90
G91
Description
There are two types of coordinate specifications: absolute and incremental.
The figure below shows the difference between absolute and incremental specifications on an X-Y plane. Absolute specifications
indicate the position as the distance from the workpiece coordinate origin, whereas incremental specifications indicate the amount of
movement from the current position.
Programming that specifies absolute coordinates is called “absolute programming,” and programming which specifies incremental
coordinates is termed “incremental programming.”
Absolute
Incremental
The settings for G90 or G91 made on the PNC-3200 remain in effect unless changed by programming.
There are no special rules for deciding when to use an absolute or incremental program. Examine the drawing and choose the one which
makes for the simplest program.
