Application planning
5.4 Redundancy scenarios
Diagnostics
System state, operating states and error displays after primary-backup switchover:
• Redundant system → RUN-Solo system state
• Primary CPU → RUN operating state
– MAINT LED → yellow light: The R/H system is not in the RUN-Redundant system state.
• Backup CPU → failed
NOTE
To get detailed diagnostics information, evaluate the diagnostics buffer.
Solution
Replace the defective CPU. You can find additional information on the procedure in the
section Replacing defective R/H CPUs (Page 321).
5.4.4
Failure of the PROFINET cable in the PROFINET ring
Introduction
The following redundancy scenario describes the effects of a defective PROFINET cable in the
PROFINET ring.
Redundancy scenario
106
No partner CPU has been found in the redundant system. The PROFINET ring is open.
S7-1500R/H redundant system
System Manual, 11/2022, A5E41814787-AD