Synchronization Modules; Synchronization Modules For S7-400H - Siemens SIMATIC S7-400H System Manual

Synchronization modules

18.1 Synchronization modules for S7–400H
Function of the synchronization modules
Synchronization modules are used for communication between two redundant S7-400H
CPUs. You require two synchronization modules per CPU, connected in pairs by fiber-optic
cable.
The system supports hot-swapping of synchronization modules, and so allows you to
influence the repair response of the fault-tolerant systems and to control the failure of the
redundant connection without stopping the plant.
The diagnostic process for synchronization modules is based on the maintenance concept
familiar from PROFINET.
If you remove a synchronization module in redundant system mode, there is a loss of
synchronization. The reserve CPU changes to ERROR-SEARCH mode for some minutes. If
the new synchronization module is inserted and the redundant link is reestablished during
this time, the reserve CPU switches to redundant system mode, otherwise it switches to
STOP.
Once you have inserted the new synchronization module and reestablished the redundant
link, you must restart the reserve CPU.
Distance between the S7–400H CPUs
Two types of synchronization module are available:
Order number
6ES7 960–1AA06–0XA0
6ES7 960–1AB06–0XA0
Long synchronization cables may increase cycle times This extension can have the factor
2 - 5 with a cable length of 10 km.
Note
A fault-tolerant system requires 4 synchronization modules of the same type.
S7-400H
System Manual, 03/2012, A5E00267695-11
Maximum distance between the CPUs
10 m
10 km
18
341