Siemens Sinumerik 840D sl Programming Manual page 363

The block with FXS[<axis>]=0 may and should contain traversing movements.
NOTICE
Risk of collision
The traversing movement to the retraction position must move away from the fixed stop,
otherwise damage to the stop or to the machine may result.
The block change takes place when the retraction position has been reached. If no retraction
position is specified, the block change takes place immediately after the torque limit has been
deactivated.
Example:
Program code
X200 Y400 G01 G94 F2000 FXS[X1]=0
...
Clamping torque (FXST) and monitoring window (FXSW)
Any programmed torque limiting FXST is effective from the block start, i.e. the fixed stop is also
approached at a reduced torque. FXST and FXSW can be programmed and changed in the
part program at any time. The changes take effect before traversing movements in the same
block.
NOTICE
Risk of collision
Programming of a new fixed stop monitoring window causes a change not only in the window
width, but also in the reference point for the center of the window if the axis has moved prior
to reprogramming. The actual position of the machine axis when the window is changed is
the new window center point.
The window must be selected such that only a breakaway from the fixed stop causes the
fixed stop monitoring to respond.
Further information
Rise ramp
A rate of rise ramp for the new torque limit can be defined in MD to prevent any abrupt changes
to the torque limit setting (e.g. insertion of a quill).
Alarm suppression
The fixed stop alarm can be suppressed for applications by the part program by masking the
alarm in a machine data item and activating the new MD setting with NEW_CONF.
Activation
Fundamentals
Programming Manual, 01/2015, 6FC5398-1BP40-5BA2
Supplementary commands
15.6 Travel to fixed stop (FXS, FXST, FXSW)
Comment
; Axis X1 is retracted from the fixed
stop to position X = 200 mm. All other
parameters are optional.
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