Siemens SINUMERIK 840Di Function Manual page 327

Functional sequence
The function is explained by the example below (sleeve is pressed onto workpiece).
Fig. 2-1
Selection
The NC detects that the function "travel to fixed stop" is selected via the command
FXS[x]=1 and signals the PLC via the IS "Activate travel to fixed stop" (DB31, ... DBX62.4)
that the function has been selected.
When the machine parameter:
MD37060 FIXED_STOP_ACKN_MASK
(register PLC acknowledgments for travel to fixed stop)
is set accordingly, the IS waits for acknowledgment by the PLC via IS "Activate travel to fixed
stop" (DB31, ... DBX3.1).
The programmed target position is then approached from the start position at the
programmed velocity. The fixed stop must be located between the start and target positions
of the axis/spindle. A programmed torque limit is effective from the start of the block, i.e. the
fixed stop is also approached with reduced torque. Allowance for this limitation is made in
the NC through an automatic reduction in the acceleration rate.
If no torque was programmed in the block or since the beginning of program, the value
entered in the axis specific machine parameter:
MD37010 FIXED_STOP_TORQUE_DEF
(default setting for clamping torque)
applies.
Travel to Fixed Stop (F1)
Function Manual, 08/2005 Edition, 6FC5397-0BP10-0BA0
Example of travel to fixed stop
Detailed Description
2.1 General functionality
2-3