Siemens SIMATIC S7-1500 System Manual page 84

Application planning
5.3 Configuration versions
Configuration variant 1
The H-CPUs are each configured in a separate PROFINET ring 1 and 2. Some or all R1 devices
are connected to these PROFINET rings via 2 switches. The R1 devices themselves are
connected via a line topology.
In this configuration variant, the availability of the media redundancy of the PROFINET rings is
limited, since the R1 devices in the lower-level line topology do not benefit from the
PROFINET ring.
①
②
③
④
⑤
⑥
⑦
⑧
Figure 5-8 Configuration variant 1
Configuration variant 2
The H-CPUs are each configured in a separate PROFINET ring 1 and 2. Switches are used to
extend PROFINET rings 1 and 2 by PROFINET rings 3 and 4. The extension of PROFINET rings 3
and 4 is connected without MRP interconnection. PROFINET rings 3 and 4 contain additional
R1 devices.
The problem with this configuration variant is that the switches in both connected MRP
domains must be MRP managers and then this role is no longer possible for the H-CPUs.
Result: The H-system does not know the state of the PROFINET rings on the backup CPU. The
synchronization terminates and the RUN-Redundant system state is not reached.
If the hardware configuration of an automation task exceeds the max. possible number of
devices in a PROFINET ring, then use MRP interconnection. With MRP interconnection, you are
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CPU 1
CPU 2
Two fiber-optic cables (redundancy connections)
PROFINET cable (PROFINET ring 1)
PROFINET cable (PROFINET ring 2)
Switch
PROFINET cable (line topology)
IO device ET 200SP (with system redundancy R1)
S7-1500R/H redundant system
System Manual, 11/2022, A5E41814787-AD