2,6,6.6 Tool Length Offset 2 - 3 - Siemens SIMATIC S5 Manual

All absolute targets are approached in a clockwise direction (forward) when G26 is selected.
On a linear axis, a G26 is ignored and does not cause a stoppage of the machining program.
All absolute targets are approached in an anti-clockwise direction (reverse) when G27 is
selected. On a linear axis, a G27 is ignored, and does not cause a stoppage of the machining
program.
Example
Rotary axis, traversing range O degrees to 360 degrees
N1 OG74 Ml O
N20G27
N30X180F1 OOOM30
N40G25XOF500
N50G26
N70G25X360F500
N80M02
Note
The G-functions G26 and G27 are only effective when "position specifications ab-
solute" (G90) is set.
Tool Length Offset
2.6.6.6
By using a tool length offset in the machining program, a change in the length of the tool during
execution of the program (usually wear on the tool) can be taken into account. This is added to a
tool length offset executed with mode BA15 ("tool length offset").
The value of the tool length offset used in the machining program is stored in the machine data.
Each time a tool length offset is called in the machining program, the value stored in the machine
data record is added to the already existing offset. The following limit values apply to the result-
ing tool length offset:
For a linear axis:
value of the offset maximum 100 m,
software end limit switch + offset value <100 m and
software start limit switch + offset >-100 m
For a rotary axis:
offset less than the traversing range. (Range end - range start),
Machining Programs and their Structure
approach the reference point by the shortest route
change direction: reverse
approach 180 degrees in reverse direction
approach O degrees/360 degrees by the shortest route, here
the preferred direction forwards
change direction: forwards
one revolution of the rotary axis forwards
since shortest route.
final statement/program end
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