Siemens Sinumerik 840D sl Programming Manual page 169

Note
The polar coordinates refer to the pole specified with G110 ... G112 and apply in the working
plane selected with G17 to G19.
Note
The 3rd geometry axis, which lies perpendicular to the working plane, can also be specified
in Cartesian coordinates (see the following diagram). This enables spatial parameters to be
programmed in cylindrical coordinates.
Example: G17 G0 AP... RP... Z...
Fundamentals
Programming Manual, 01/2015, 6FC5398-1BP40-5BA2
10.3 Travel commands with polar coordinates
Motion commands
169