Siemens SIMATIC S5 Manual page 126

You can also specify a tool offset in the machine data which can be switched on within machin-
ing programs by G43 or G44. (=> Section 2.6.6 "The G-Functions"). This offset is added to the
offset specified with mode 15 and can be called repeatedly. This allows, for example, the esti-
mated wear on a tool to be taken into account within the machining program by setting the tool
length with mode 15 and then calling the tool length offset from the machine data in the machin-
ing program to make up for the tool wear.
The tool length offsets executed in a machining program are not cancelled at the end of the pro-
gram. They are retained just as the tool offset set with mode 15, even after the IP247 is switched
off, If however new machine data are entered or the existing machine data are modified, the ex-
isting tool offset is cleared.
Each new tool offset set with BA15 overwrites the previously effective tool offset. This applies to
offsets set with BA15 or switched on during a machining program.
Special features for a rotary axis
If a tool offset of 30 degrees forward (clockwise) is executed at position 60 degrees for a rotary
axis, the actual position is then signalled as 90 degrees (tool tip), The actual traversing range is,
however, still between O degrees and 360 degrees. The coordinate system is therefore turned.
On the other hand, with a zero offset the coordinate system is transformed to a different numeri-
cal range.
Executing Machining Programs
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