Siemens SINUMERIK 802D sl Programming And Operating Manual page 250

Programming
10.3 Axis movements
Fixed stop reached
When the fixed stop has been reached:
● The distance-to-go is deleted and the position setpoint is manipulated.
● The drive torque increases to the programmed limit value FXST[ ]=... or the value from
● The monitoring of the fixed stop is active within the specified window width (FXSW[ ]=...
Deselecting the function
Deselection of the function triggers a preprocessing stop. The block with FXS[X1]=0 must
contain traversing movements.
Example:
N200 G1 G94 X200 Y400 F200 FXS[X1] = 0
Note
The traversing movement to the retraction position must lead away from the fixed stop;
otherwise, damage to the fixed 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 once the torque limit has
been deactivated.
Note
"Measuring with deletion of distance-to-go" ("MEAS" command) and "Travel to fixed stop"
cannot be programmed in the same block.
Contour monitoring is not performed while "Travel to fixed stop" is active.
If the torque limit is reduced too far, the axis will not be able to follow the specified setpoint;
the position controller then goes to the limit and the contour deviation increases. In this
operating state, an increase in the torque limit may result in sudden, jerky movements.
Ensure that the axis can still follow. For this reason, it must be verified that the contour
deviation is not larger than that with unlimited torque.
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 spindle sleeve or quill).
250
SD and then remains constant.
or value from SD).
; Axis X1 is retracted from the fixed
stop to position X= 200 mm.
Programming and Operating Manual, 11/2012, 6FC5398-5CP10-3BA0
Surface grinding