Siemens SITOP PSU100C 6EP1321-5BA00 Operating Instructions Manual page 50

Applications
9.2 Parallel connection for redundancy
Figure 9-3
You can find additional information at:
SITOP PSE202U manual (http://support.automation.siemens.com/WW/view/en/42248598)
50
Parallel connection with redundancy module for NEC Class 2
Operating Instructions, 06.2013, C98130-A7599-A1-2-7629
SITOP PSU100C