Siemens SINUMERIK 840D sl Function Manual page 124

F2: Multi-axis transformations
1.12 Online tool length offset
Reset
Compensation values can be reset with the TOFFOF( ) command. This instruction triggers a
preprocessing stop.
Accumulated tool length compensations are cleared and incorporated in the basic coordinate
system. The run-in is synchronized with the current position in main run. Since no axes can
be traversed here, the values of $AA_IM[ ] do not change. Only the values of the variables
$AA_IW[ ] and $AA_IB[ ] are changed. These variables now contain the deselected share of
tool length compensation.
Once "Online tool length offset" has been deselected for a tool direction, the value of system
variable $AA_TOFF[ ] or $AA_TOFF_VAL[ ] is zero for this tool direction. The following
interface signal is set to 0:
DB21, ... DBX318.2 (TOFF active)
Alarm 21670
An existing tool length offset must be deleted via TOFFOF( ) so that alarm 21670 "Channel
%1 block %2, illegal change of tool direction active due to $AA_TOFF active" is suppressed:
• When the transformation is deactivated with TRAFOOF
• On switch-over from CP to PTP travel.
• If a tool length offset exists in the direction of the geometry axis during geometry
replacement.
• If a tool length offset is present during change of plane.
• When changing from axis-specific manual travel in JOG mode to PTP as long as a tool
length compensation is active. There is no switchover to PTP.
Mode change
Tool length compensation remains active even if the mode is changed and can be executed
in any mode.
If a tool length compensation is interpolated on account of $AA_TOFF[ ] during mode change,
the mode change cannot take place until the interpolation of the tool length compensation has
been completed. Alarm 16907 "Channel %1 action %2 ALNX possible only in stop state" is
issued.
Behavior with REF and block search
Tool length offset is not considered during reference point approach REF in JOG mode.
The instructions TOFFON( ) and TOFFOF( ) are not collected and output in an action block
during block search.
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Function Manual, 09/2011, 6FC5397-2BP40-2BA0
Special Functions