Network topologies and media redundancy 
  1.3 Media redundancy in ring topologies 
SCALANCE X-200 
Configuration Manual, 03/2015, C79000-G8976-C285-06 
19 
 
Media redundancy in ring topologies 
Structure of a ring topology 
Nodes in a ring topology can be external switches and/or the integrated switches of 
communications modules. 
To set up a ring topology with media redundancy, you bring together the two free ends of a 
linear bus topology in one device. Closing the linear bus topology to form a ring is achieved 
with two ports (ring ports) of a device in the ring. This device is the redundancy manager. All 
other devices in the ring are redundancy clients. 
 
Figure 1-8  Devices in a ring topology with media redundancy 
The two ring ports of a device are the ports that establish the connection to its two 
neighboring devices in the ring topology. The ring ports are selected and set in the 
configuration of the relevant device. In STEP 7 and on the S7 Ethernet CP modules 
themselves, the ring ports are indicated by an "R" after the port number. 
 
Note 
Before physically closing the ring, download the configuration of your STEP
 7 project to the