Siemens SINUMERIK 808D Programming And Operating Manual page 45

G function
G41
G42
The commands G40 and G41/G42 are modal G functions of the G group 07. These remain active for as long as till another
function of this G group is programmed. Closed position after POWER ON or NCK-RESET is G40.
The tool nose radius compensation is called either with G41 or with G42 and a T command.
Defining the tool nose radius compensation depending upon the machining direction:
Change of the compensation direction
The compensation direction can be switched between G41 and G42 without deselecting G40. The last block with the old
compensation direction ends with the normal position of the compensation vector at the end point. The new compensation
direction is executed as a compensation start (default setting at starting point).
Contour of the motions in case of tool radius compensation
The following figure shows the execution of the tool radius compensation:
Upon selection (block 1) and deselection (block 6) of the tool nose radius compensation the compensating movements are
carried out. Therefore, while selecting or deselecting the tool offset, be very careful that no collisions take place.
Programming and Operating Manual (ISO Turning/Milling)
01/2017
Function
Tool radius compensation (tool operates in machining direction to the left
of the contour)
Tool radius compensation (tool operates in machining direction to the
right of the contour)
G group
07
07
45