Siemens SIMATIC FM 353 Manual page 291

Incremental dimensioning G91
Incremental dimensioning is the method used to specify incremental dimensions
that refer to the last actual position.
Fig. 10-2
FM 353 Stepper Drive Positioning Module
6ES7 353-1AH01-8BG0
/ N G1 G2 G3 X/t
91
−30
Programmed
position
0
10 20 30
Incremental input G91
Writing Traversing Programs
F M1 M2 M3 D
100
Actual position
40 50 mm
10-9