Application planning
6.5 Failure scenarios
Diagnostics
System state, operating states and error displays after the failure of an IO device:
• Redundant system → RUN-Redundant system state
• Primary CPU/Backup CPU → RUN-Redundant operating state
– MAINT LED: → yellow light: The PROFINET ring is open. Singular redundancy
– ERROR LED → flashes red: An IO device has failed.
Failure of the redundant system
If the primary CPU fails in addition to the PROFINET cable, the backup CPU switches to the
STOP operating state. You can find more information in the section Failure of the primary
CPU when IO devices have failed in the PROFINET ring (Page 206).
Note
To get detailed diagnostics information, evaluate the diagnostics buffer.
Solution
Replace the defective IO device. You can find additional information on the procedure in the
section Replacing defective I/O devices/switches (Page 455).
6.5.2
Failure of a switch (with additional line topology) in the PROFINET ring
Introduction
The following failure scenario describes the effects of a defective switch (with additional line
topology) in the PROFINET ring.
200
connection available.
WARNING
S7-1500R/H redundant system
System Manual, 01/2024, A5E41814787-AF