Reference-Measure Input G90; Incremental Input G91 - Siemens SIMATIC S7-300 Manual

Writing Traversing Programs
Dimensions G90, The traversing movement at a specific point can be described by
G91
You can switch back and forth at will between reference-measure and incre-
mental input.
The status at startup is reference-measure programming, G90.
G90 and G91 are modal.
Absolute
Absolute dimensioning is the method used to specify dimensions that gener-
dimensioning G90
ally refer to the coordinate system.
Fig. 10-1 Reference-measure input G90
Note
To ensure precise reproduction of the program, the first block should contain
reference-measure programming.
Incremental
Incremental dimensioning is the method used to specify incremental dimen-
dimensioning G91 sions that refer to the last actual position.
Fig. 10-2 Incremental input G91
10-8
Reference-measure input (absolute measure input) G90 or
Incremental input (relative measure input) G91
/ N G1 G2 G3
90
Programmed
Position
0
10 20
/ N G1 G2 G3
91
Programmed
Position
0 10 20
X/t F M1 M2 M3 D
20 100
Actual position
30 40 50 mm
X/t F M1 M2 M3 D
–30 100
Actual position
30 40 50 mm
FM 354 Servo Drive Positioning Module