Hardware Installation And Configuration Of The Redundant I/O - Siemens SIMATIC S7-400H Manual

Using I/O on the S7-400H

Hardware installation and configuration of the redundant I/O

If you wish to use a redundant I/O, we would recommend you the following
strategy:
1. Insert all of the modules that you wish to use redundantly. Pay attention to the
following default rules for the configuration.
2. Configure the module redundancy using HW Config in the object properties for
the respective module.
3. Either look for a partner module for each module or use the default settings
In a centralized configuration: Insert the module in an even rack in slot X, the
redundant module in the next odd rack is inserted in the same slot.
If the module in the odd rack is inserted in slot X, the same slot in the preceding
even rack is suggested for the module.
Distributed in the one-way DP slave: If the module in the slave is inserted in
slot X, provided that the DP master system is redundant, the same PROFIBUS
address in the same DP subsystem is suggested for the module in the partner
DP subsystem in the slave.
Distributed in the switched DP slave, single mode: If the module in the
slave is inserted with a DP address in slot X, the module in the slave with the
next PROFIBUS address at slot X is suggested.
4. Enter the remaining redundancy parameters for the input modules.
Caution
Always switch off the station or the rack before you remove a module, otherwise
you may disable the wrong module.
The valid value that can be processed by the user program are always at the lower
address of both redundant modules. This way only the lower address can be used
by the application; the values of the higher address are not relevant for the
application.
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Automation System S7-400H Fault-tolerant Systems
A5E00068197-07