Selecting The Trc (G41/G42) - Siemens SINUMERIK 828D Function Manual

18.5.2

Selecting the TRC (G41/G42)

Direction of compensation
TRC calculates a path, which is equidistant to the programmed contour. Compensation can be performed on the
left- or right­hand side of the programmed contour in the direction of motion.
Command Significance
TRC on the left­hand side of the contour in the direction of motion
G41
TRC on the right­hand side of the contour in the direction of motion
G42
Deselection of TRC
G40
Intermediate blocks
In general, only program blocks with positions on geometry axes in the current plane are programmed when TRC
is active. However, dummy blocks can still also be programmed with active TRC. Dummy blocks are program
blocks, which do not contain any positions on a geometry axis in the current plane:
• Positions on the infeed axis
• Auxiliary functions,
• etc.
The maximum number of dummy blocks can be defined in the machine data:
MD20250 $MC_CUTCOM_MAXNUM_DUMMY_BLOCKS (Max no. of dummy blocks with no traversing
movements for TRC).
Special points to be noted
• TRC can only be selected in a program block with G0 (rapid traverse) or G1 (linear interpolation).
• A tool must be loaded (T function) and the tool cutting edge (tool compensation) (D1 to D9) activated no later
than in the program block with the tool radius compensation selection.
• Tool radius compensation is not selected with a tool cutting edge/tool compensation of D0.
• If only one geometry axis is programmed on the plane when tool radius compensation is selected, the second
axis is automatically added on the plane (last programmed position).
• If no geometry axis is programmed for the current plane in the block with the tool radius compensation
selection, no selection takes place.
• If tool radius compensation is deselected (G40) in the block following tool radius compensation selection, no
selection takes place.
• If tool radius compensation is selected, the approach behavior is determined by the NORM/KONT instructions.
Basic Functions
Function Manual, 09/2011, 6FC5397-0BP40-2BA0
18.5 Tool radius compensation 2D (TRC)
W1: Tool offset
1459