Siemens SINUMERIK 840D sl Operating Manual page 37

Notice
If the axes are not in a collision-free position, you must first traverse them to safe positions in
"JOG" or "MDA" mode.
You must follow the axis motions directly on the machine!
Ignore the actual value display until the axes have been referenced!
The software limit switches are not active!
Proceed as follows
The axis is referenced as soon as the reference point is reached. The actual value display is
set to the reference point value.
From now on, path limits, such as software limit switches, are active.
End the function via the machine control panel by selecting operating mode "AUTO" or
"JOG".
HMI sl Universal
Operating Manual, 11/2006, 6FC5398-6AP10-1BA0
Machine manufacturer
Please also refer to the machine manufacturer's instructions.
1. Press the "JOG" key.
2. Press the "REF POINT" key.
3. Select the axis to be traversed.
...
4. Press the "+" or "-" key.
...
The selected axis moves to the reference point.
If you have pressed the wrong direction key, the action is not
accepted and the axes do not move.
A symbol is shown next to the axis if it has been referenced.
Setting up the machine
2.3 Approaching a reference point
37