Siemens SIMATIC FM 452 Manual page 105

Effects on a Linear Axis
Based on the example of a zero offset of -200 mm you can see that this setting
shifts the coordinate system in a positive direction. The following effects result:
The working range is not physically shifted.
The individual points (such as the software limit switches) are assigned new
coordinate values.
The cams retain their coordinate values and are therefore located at a different
physical position.
When the axis is synchronized and the cam processing is enabled, the actual
position can skip cam edges or complete cams as a result of this setting.
Status changes of the cam which would normally trigger an interrupt can be
lost.
Table 9-2 Coordinate System Shift Resulting from Zero Offset
SLS
–500
–500
Note
Note the switching response of time cams in Section 9.1, Page 9-2.
FM 452 Electronic Cam Controller
C79000-G7076-C452-04
Zero offset
Old coordinate system
ACT SLE
500
0
200
Coordinate
shift of
200 mm 200 mm
resulting from
zero offset of
-200 mm
400
0
New coordinate system
SLS
[mm]
[mm]
-400
-200
[mm]
Settings
ACT SLE
[mm] [mm]
200 400
400 600
9-7