Siemens SINAMICS S120 Function Manual page 496

Function modules
7.9 Master/slave function for Active Infeed
Topology
Figure 7-23
Master/slave operation can be implemented for a maximum of four Active Line Modules.
494
Topology structure and communications network based on PROFIBUS for master/slave
operation with redundant infeeds (four infeed trains)
Function Manual, (FH1), 01/2013, 6SL3097-4AB00-0BP3
Drive functions