Siemens SINUMERIK 840D sl Function Manual page 1436

W1: Tool offset
18.5 Tool radius compensation 2D (TRC)
● If CUTCONON is programmed with active tool radius compensation and not canceled before
the end of the program, the traversing blocks are traversed with the last valid compensation.
The same applies for reprogramming of G41 or G42 in the last traversing block of a program.
● If tool radius compensation is activated with G41 or G42 and CUTCONON is also already
active, activation of compensation is delayed until the next traversing block with
CUTCONOF.
● When reapproaching the contour with CUTCONOF, the 17th G-code group (approach and
retraction behavior with tool compensation; NORM / KONT) is evaluated, i.e. a bypass circle
is inserted if necessary for KONT. A bypass circle is inserted under the same conditions as
for activation of tool radius compensation with G41 or G42.
● The number of blocks with suppressed tool radius compensation is restricted:
MD20252 $MC_CUTCOM_MAXNUM_SUPPR_BLOCKS (Maximum number of blocks with
compensation suppression).
If it is exceeded, machining is aborted and an error message issued.
The restriction is necessary because the internal block processing in the last block before
CUTCONON must be resumed when repositioning.
● The response after reprogramming G41 or G42 when tool radius compensation is already
active is similar to compensation suppression.
The following deviations apply:
– Only linear blocks are permissible
– A single traversing block that contains G41 or G42 is modified so that it ends at the offset
– The contour is always reapproached with NORM, independent of the G code of the 17th
● If G41 / G42 is programmed several times in consecutive traversing blocks, all blocks are
machined as for CUTCONON, except for the last one.
● The type of contour suppression is evaluated only in the first traversing block of a sequence
of consecutive traversing blocks.
If both CUTCONON and G41 or G42 are programmed in the first block, the response to
deactivating contour suppression is determined by CUTCONON.
Changing from G41 to G42 or vice versa makes sense in this case as a means of changing
the compensation side (left or right of the contour) when restarting.
A change of compensation side (G41/G42) can also be programmed in a later block, even
if contour suppression is active.
● Collision detection and bottleneck detection is deactivated for all blocks with active contour
suppression.
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point of the start point in the following block. Thus it is not necessary to insert a dummy
block. The same applies to the last block in a sequence of traversing blocks where each
contains G41 or G42.
group (approach and retraction behavior with tool compensation; NORM / KONT).
Function Manual, 01/2015, 6FC5397-0BP40-5BA2
Basic Functions