Siemens SIMATIC PCS 7 Function Manual page 87

Redundancy connection
You need the following components to make the redundancy connection, depending on the
distance to be bridged:
Maximum distance
10 m
100 m
1000 m
Availability
The availability of the complete system is ensured even if one of the two OS servers fails
because the two OS servers form an independent redundancy node.
Fault-tolerant Process Control Systems (V8.1)
Function Manual, 11/2014, A5E34878832-AA
Required components
Null modem cable
● Crossover network cable
● Per server: A free network connection (see
section "Network components (Page 46)")
Fiber-optic cable
Per server:
● A free network connection
(see section "Network components
(Page 46)")
● 1 Ethernet cable
● 1 media converter
(e.g., SCALANCE X101-1)
Fault-tolerant Solutions in PCS 7
3.5 Solutions for OS servers
Connection
Serial connection
Ethernet connection
Ethernet connection
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