Siemens SIMATIC S7-1500 System Manual page 445

Maintenance
14.1 Replacing components of the S7-1500R/H redundant system
Checking pairing state
You have the following options for checking the pairing state:
• Directly from the display of the backup CPU.
In the "Overview > Redundancy > Pairing state" menu:
– Paired
– Single paired (X*P*)
– Not paired
– Not paired - Too many partners
– Not paired - Article number mismatch
– Not paired - Firmware mismatch
444
Primary CPU
Example: Paired
Backup CPU
S7-1500R/H redundant system
System Manual, 01/2024, A5E41814787-AF