Siemens SIMATIC S7-1500 System Manual page 102

System redundancy R1
As of FW version V3.0, the S7-1500H redundant system supports IO devices with system
redundancy R1.
System redundancy R1 is the connection of an IO device via two interface modules, each of
which supports an AR to an IO controller in the redundant system. An IO device can
communicate via two separate PROFINET networks (subnets) through the two interface
modules.
IO devices with system redundancy R1 enable uninterrupted process data exchange with the
S7-1500H redundant system when:
• a CPU fails
• Interruption of the PROFINET ring or of the line topology
• an interface module fails
• a subnet fails.
Unlike system redundancy S2, system redundancy R1 has a separate interface module for
each of the two ARs. Due to these redundant interface modules, the availability is higher than
with an S2 device.
• Behavior in RUN-Redundant system state:
The PROFINET communication runs on both system redundancy ARs simultaneously, each
between one of the CPUs (IO controller) and an interface module of the R1 device.
In the case of failure of an interface module of an R1 device, only the ARs switch over. The
roles of the H-CPUs do not change.
If, however, the primary CPU fails or is switched to STOP, the S7-1500H redundant system
then behaves as follows:
– The previous backup CPU becomes the new primary CPU.
– The new primary CPU uses the AR to the other interface module of the IO device and
– The AR between the previous primary CPU and the assigned interface module is
• Behavior in RUN-Solo system state:
Only the primary CPU is IO controller. PROFINET communication runs on the AR between
the primary CPU (IO controller) and the interface module of the IO device assigned to the
primary CPU. The backup CPU separates all its ARs.
In STEP 7 you configure an IO device with system redundancy R1 by:
• Connecting the left interface module of the R1 device to the H-CPU with redundancy ID 1.
• You have to connect the right interface module of the R1 device to the H-CPU with
redundancy ID 2.
S7-1500R/H redundant system
System Manual, 01/2024, A5E41814787-AF
still has access to the inputs and control over the outputs of the IO device.
disconnected.
System overview
5.3 S7-1500 R/H-CPUs
101