Siemens Simatic S7-1500R System Manual page 192

Switching redundancy IDs over the display
After each of the CPUs has its own redundancy ID, you want to the switch the redundancy
IDs of the CPUs.
Switching redundancy IDs can, for example, be useful in the following situations:
● You only have access to one of the two CPUs.
● You have incorrectly assigned the redundancy IDs.
Note
Switching the redundancy IDs switches the assignment of the real CPUs to the project trees
in the project navigation.
If the two CPUs contain the same project, switching the redundancy IDs switches all
configured properties between the CPUs. These include, for example, the IP addresses of
the PROFINET interfaces, the device names and the configured topology.
On the display, you can exchange on only one CPU the redundancy IDs already assigned
for both CPUs.
Proceed as follows to switch the redundancy IDs:
1. Make sure that both CPUs are in STOP operating state:
2. Make sure that the two CPUs are connected to each other.
3. Change the redundancy ID of a CPU using the display.
Result: Once the redundancy ID has been changed on one CPU, both CPUs restart and
each now has the redundancy ID of the other.
Incompatible assignment of redundancy IDs
There is pairing between the two CPUs. You can find more information in the section CPU
pairing (Page 184).
In the following case, the system automatically checks the compatibility of the redundancy
IDs:
● Both CPUs are in STOP operating state and they have the same redundancy ID.
If the same redundancy ID has been assigned to both CPUs, the ERROR LEDs on both
CPUs flash in red. Each CPU display indicates an assignment conflict. The CPUs generate
an entry in the diagnostics buffer. You can read the entry on the display, for example.
To establish redundant mode, resolve the assignment conflict in one of the following ways:
● Assign a different redundancy ID to one CPU using the display.
● Switch the CPU that is to retain its assigned redundancy ID to the RUN operating state.
Behavior of the CPUs when redundancy IDs are changed
Please note that you can only change the redundancy ID of a CPU in STOP operating state.
After each successful change of a redundancy ID, the CPU in question automatically
restarts.
S7-1500R/H redundant system
System Manual, 10/2018, A5E41814787-AA
Commissioning
9.3 Commissioning procedure
191