Siemens Simatic PCS 7 Function Manual page 40

High availability solutions in PCS 7
4.1 Solutions for the I/O
Installation rules
The configuration always has to be symmetrical when using redundant I/O. Follow these
installation rules:
● Using ET 200M as distributed I/O device: Both subsystems of the S7 400H must be
configured identically. The same modules are located at the same slots.
Example: CPU and CPs are located in both subsystems at the same slot.
● Using ET 200SP HA as distributed I/O device: By using IO redundancy the terminal block
(TB45...) only needs to be connected to the fielddevice (sensor or actor).
● The communication paths and interfaces must be configured the same way in both
subsystems.
Example: The fieldbus cables in both subsystems are connected to the same bus interface
of the CPU 41x-xH.
● Redundant modules are always identical (article number, hardware version, firmware
version)
Configuration rules
● In a PROFIBUS System
A DP slave must have the same PROFIBUS address in the mutually redundant DP master
systems.
● In a PROFINET IO System
The first module in Redundant I/O must be placed at an odd-numbered slot on a terminal
block (TB45...).
Redundant I/O of ET 200SP HA
Redundant I/O of ET 200SP HA describes the situation when a pair of I/O modules (SM) use
the same connectors for the sensor/actuator. The CPU signal or process signal will continue
to be processed by a functioning module even when its partner fails. The entire signal path up
to the sensor/actuator can configured redundantly.
Note
With PCS 7, you can determine if errors in redundantly acquired signals will have an effect on
a module or channel. You can find additional information about this in the following sections:
● Section "Redundant I/O modules (Page 46)"
● Section "Failure of redundant interface modules (Page 199)"
Configuration
In PCS 7, you can configure Redundant I/O with selected IO modules from ET 200SP HA.
The ET 200SP HA distributed I/O is connected as a PROFINET IO-Device to a automation
system operating as the IO Controller via PROFINET IO. A redundant configuration of IO
modules is achieved by installing 2 identical IO modules on a terminal block for Redundant I/
O (TB45...).
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High Availability Process Control Systems (V9.0)
Function Manual, 05/2017, A5E39221836-AA