Siemens SINUMERIK 840D sl, Function Manual

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Detailed Description
2.4 Tool radius compensation 2D (TRC)
Basic logic functions: Tool Offset (W1)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0
69
Velocities at retraction
During retraction, the rolls of the modally active feedrate from the previous block and the
programmed feedrate value in the SAR block are interchanged, i.e., the actual retraction
contour (straight line, circle, helix) is traversed with the old feedrate value and a new velocity
programmed with the F word applies from point P
2
up to P
0
.
If even retraction is active and
FAD
is programmed, the path from P
3
to P
2
is traversed with
FAD
, otherwise it is traversed with the old velocity. The last F command programmed in a
preceding block always applies for the path from P
4
to P
2
.
G0
has no effect in these blocks.
Traversing from P
2
to P
0
takes place with the F command programmed in the SAR block or,
if no F command is programmed, with the modal F command from a preceding block. This
applies on the condition that
G0
is not active.
If rapid traverse is to be used on retraction in the blocks from P
2
to P
0
,
G0
must be activated
before the SAR block or in the SAR block itself. If an additional F command is programmed
in the actual SAR blocks, it is then ineffective. However, it remains modally active for
following blocks.
1RYHORFLW\SURJUDPPHG
2QO\)SURJUDPPHG
2QO\)$'SURJUDPPHG
)DQG)$'SURJUDPPHG
9HORFLW\RISUHFHGLQJEORFNROG)FRPPDQG
5HWUDFWLRQYHORFLW\SURJUDPPHGZLWK)$'
1HZPRGDOYHORFLW\SURJUDPPHGZLWK)
5DSLGWUDYHUVHLI*LVDFWLYHRWKHUZLVHZLWKWKHROGRUQHZ)FRPPDQG
3 3 3 3 3
Figure 2-24 Velocities in the SAR subblocks on retraction