Online Tool Length Compensation ($Aa_Toff) - Siemens SINUMERIK 840D sl Function Manual

Detailed description
3.3 System variables for synchronized actions
3.3.18

Online tool length compensation ($AA_TOFF)

Function
In conjunction with an active orientation transformer or an active tool carrier, tool length
compensations can be applied during processing/machining in real time. Changing the
effective tool length using online tool length compensation produces changes in the
compensatory movements of the axes involved in the transformation in the event of changes
in orientation. The resulting velocities can be higher or lower depending on machine kinematics
and the current axis position.
Velocity and acceleration with which specified tool length compensations can be traversed via
the system variable $AA_TOFF, can be specified via the following machine data:
● MD21194 $MC_TOFF_VELO (velocity, online offset in tool direction)
● MD21196 $MC_TOFF_ACCEL (acceleration, online offset in tool direction)
For further information regarding the activation of the function, see:
References:
Programming Manual, Job Planning; Section "Transformations "TOFFON, TOFFOF""
Applications in synchronized actions
In synchronized actions, tool length compensations can be applied in all three dimensions via
the system variable $AA_TOFF. The three geometry axis names X, Y, Z are used as index.
All three offset directions can be active at the same time.
For an active orientation transformation or for an active tool carrier that can be oriented, the
offsets are effective in the respective tool axes. An overlaid motion must be switched off with
TOFFOF() before switching a transformation on or off.
After deselection of the tool length compensation in one dimension, the value of the system
variable $AA_TOFF in this dimension is equal to 0.
Mode of operation of the offset in the tool direction
The tool length compensations do not change the tool parameters, but are taken into account
within the transformation or the tool carrier that can be orientated, so that offsets are obtained
in the tool coordinate system.
For each dimension, it is possible to define whether the tool length compensation specified in
$AA_TOFF should be calculated as an absolute or incremental (integrating) value via the
following machine data:
MD21190 $MC_TOFF_MODE (operation of tool offset in tool direction)
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Function Manual, 08/2018, 6FC5397-5BP40-6BA2
Synchronized actions