Siemens Simatic PCS 7 Function Manual page 55

Overview of the redundant and high availability bus systems
In PCS 7 systems, you can configure fully redundant bus systems with redundant components
for the following bus systems:
● Redundant, high availability terminal bus (Page 63)
● Redundant, high availability plant bus (Page 71)
● Redundant PROFIBUS DP (Page 76)
Bus systems set up as a ring are high availability. In ring structures, the signal path remains
intact even if there is a disconnection on the transmission cable at any point in the ring (for
example due to a wire break). The availability is ensured by ring redundancy.
This high availability is used in the following bus systems:
● High availability terminal bus (Page 61)
● High availability plant bus (Page 69)
● High availability PROFIBUS PA (Page 83)
● High availability FOUNDATION Fieldbus (Page 90)
● High availability fieldbus based on PROFINET (Page 78)
The following sections describe the basics of these communications solutions.
High Availability Process Control Systems (V9.0)
Function Manual, 05/2017, A5E39221836-AA
High availability solutions in PCS 7
4.3 Solutions for communication
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