Siemens SIMATIC PCS 7 Function Manual page 69

Availability
If the active PROFIBUS DP fails, sensors and H system can communicate with each other
over the redundant bus connection. The configuration shown in the following figure provides
increased availability due to the redundant interfacing of the distributed I/O.
Additional information
● Section "How to configure redundant PROFIBUS DP (Page 114)"
● Manual
● Manual
Fault-tolerant Process Control Systems (V8.1)
Function Manual, 11/2014, A5E34878832-AA
SIMATIC Net PROFIBUS Networks
SIMATIC; Communication with SIMATIC
Fault-tolerant Solutions in PCS 7
3.3 Solutions for communication
69