Siemens SIMATIC PCS 7 Function Manual page 42

Fault-tolerant Solutions in PCS 7
3.2 Solutions for automation systems
Synchronization modules
Synchronization modules are used to link the two central processing units. They are installed
in the central processing units and interconnected with fiber-optic cable. Two synchronization
modules are installed in each CPU.
Set the rack number for the H CPU as of firmware version V4.X directly on the CPU. The
synchronization modules can be replaced in runtime.
The same rack number must be set at all synchronization modules up to firmware V3.x.
Fiber-optic cables for synchronization
The fiber-optic cables are connected to the synchronization modules and form the physical
connection (redundancy link) between the two automation stations. The synchronization
cables must not be cross-connected.
In addition to the standard lengths of 1 m, 2 m, and 10 m, custom-made synchronization cables
are available in lengths up to 10 km.
Transmission medium
The suitable physical transmission medium depends on the range, resistance to interference
and the transmission rate.
● Industrial Ethernet using fiber-optic cables or triaxial or twisted-pair copper lines can be
used for communication between the automation system and the OS servers.
● PROFIBUS DP with electrical or optical components is used for communication from the
automation system to the distributed I/O devices.
The transmission media and communications processors can be configured redundantly. If
the active communication component (CP, bus) fails, the communication automatically
continues through the redundant connection.
Only Industrial Ethernet with ISO protocol can be used as the plant bus for a fault-tolerant
system. The communication modules must also support the ISO protocol.
Equipping the rack
The hardware setup in the automation system and the configuration in HW Config must match:
● Rack (4, 9 or 18 slots for redundant and, in some cases, remote configuration)
● Power supply modules (in some cases redundant configuration)
● H CPU with sync modules in slots "IF1" and "IF2"
● If necessary: Communications processors (CP 443-1, CP 443-5 Extended)
Configuration
A pre-existing network can be used for fault-tolerant communication between non-redundant
SIMATIC stations and (redundant) SIMATIC H stations. You set the parameters of the fault-
tolerant S7 connections in NetPro.
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Fault-tolerant Process Control Systems (V8.1)
Function Manual, 11/2014, A5E34878832-AA