Siemens SINUMERIK 802D sl Function Manual page 75

Note
It is not permissible to program a new position for an axis if the "Travel to fixed stop" function
has already been activated for an axis/spindle (not an analog spindle). The spindle must be
switched to position-controlled mode before the function is selected.
System variable $AA_FXS[X1] for status
This system variable provides the "Travel to fixed stop" status for the axis specified:
Value = 0: Axis not at fixed stop.
Query of the system variables in the part program initiates a preprocessing stop.
As a result of the status query in the part program, it is possible, for example, to react to an
erroneous operational sequence of the "Travel to fixed stop" function.
Example of function
Figure 5-1
Turning, Milling, Nibbling
Function Manual, 11/2012, 6FC5397-1CP10-5BA0
1: Fixed stop successfully approached
(axis is in fixed stop monitoring window).
2: Approach to fixed stop has failed (axis is not at fixed stop).
3: Travel to fixed stop activated.
4: Fixed stop detected.
5: Travel to fixed stop will be de-selected, the de-selection is not yet completed.
Example for travel to fixed stop - sleeve is pressed onto the workpiece
Travel to fixed stop (F1)
5.2 Functionality
75