Siemens SIMATIC FM 353 Manual page 221

When crossing the RPS, a signal length of ∆t w 2@FM cycle must be assured!
The following table shows you the exact location of the synchronization point on
the current-sourcing pattern zero or zero pulse external.
Synchronization point encoder Selec-
Current-sourcing pattern zero
Zero pulse external (NIX)
Using a reversing switch
If it is possible for the axis to be "behind" the reference point switch when you start
reference point approach, a reversing switch can be installed at the end of the axis
in the approach direction, in order to reverse the axis in the direction of the refer-
ence point switch.
On axis movements with referencing feed, a signal length of ∆t w 2@FM
cycle must be assured for the reversing switch!
Example
Axis position
RPS
The value for the reference-point shift (MD27) is traveled after the synchronization
point is reached.
FM 353 Stepper Drive Positioning Module
6ES7 353-1AH01-8BG0
tion in MD37
Approach direction from MD18
Reversing
Reference point
switch
Description of Functions
Applicable for type (0 − 3) of the refer-
ence point approach per MD18
V
R
RPS
V
R
NIX
RPS
Center
Emergency
limit switch
9-21