Siemens SINUMERIK 840DE

Tool offsets
8.11 Smooth approach and retraction
Fundamentals
8-54 Programming Manual, 10.2004 Edition, 6FC5 298-7AB00-0BP1
Reading positions
Points P
3
and P
4
can be read in the WCS as a system variable during approach.
• $P_APR: reading P
•
3
(initial point)
• $P_AEP: reading P
•
4
(contour starting point)
• $P_APDV: read whether $P_APR and $P_AEP contain valid data
8.11.2 Approach and retraction with enhanced retraction strategies (G460, G461, G462)
Function
In certain special geometrical situations, enhanced approach and retraction strategies,
compared with the previous implementation with activated collision monitoring for approach
and retraction block, are required in order to activate or deactivate tool radius compensation.
For instance, collision monitoring can lead to a section of the contour not being fully
machined. See following image.
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Retraction behavior with G460
Programming
G460
Or
G461
or
G462
Parameters
G460 As before (activation of collision monitoring for approach
and retraction block)
G461 Insertion of a circle in the TRC block, if no intersection
point is possible, whose center point is at the end point
of the uncorrected block and whose radius is equal to the
tool radius.
Auxiliary circuit is used to machine around the contour
end
p
oint (i.e. u
p
to the end of the countour) u
p
to the
ii