Is Profibus-DP master-master communication possible? How many stations are supported?

Yes, master-master communication is possible (FDL). Up to 126 masters can operate on the Profibus-DP network. The Profibus master module PCD7.F750 is necessary for this. The maximum number of specific FDL connections (39) in the Simatic-Manager should also be taken into account. Unspecified FDL connections can be used in addition.