Communication Via Redundant S7 Connections - Siemens SIMATIC PCS 7 CPU 410-5H System Manual

Supplementary information
15.9 Communication via S7 connections
15.9.2

Communication via redundant S7 connections

Availability
Availability compared to using a single bus (see figure below) can be enhanced by using a
redundant system bus and two separate CPs in a standard system.
Figure 15-11 Example of linking standard and fault-tolerant systems in a single bus system
Redundant communication can also be operated with standard connections. For this two
separate S7 connections must be configured in the program in order to implement
connection redundancy. In the user program, both connections require the implementation of
monitoring functions in order to allow the detection of failures and to change over to the
standby connection.
264
CPU 410-5H Process Automation
System Manual, 09/2014, A5E31622160-AB