Siemens SIMATIC S7-1500 System Manual page 226

Failure scenario
①
②
③
④
⑤
⑥
Figure 6-60
Sequence
1. The CP 1543-1 at the primary CPU fails. The primary CPU remains in the RUN operating state
and does not change roles.
2. The connection to Industrial Ethernet is maintained via the IP address assigned to the CP
1543-1 (device IP address) at the backup CPU.
3. The backup CPU also fails.
4. The redundant system switches to the RUN-Solo system state.
5. The connection to the Industrial Ethernet is interrupted.
6. This failure affects the communication connection of the CPs because the redundant system
has no connection to the Industrial Ethernet.
Diagnostics
System state, operating states, and error displays after the failure of the CP at the primary
CPU and backup CPU:
• Redundant system → RUN-Solo system state
• Primary CPU → RUN operating state
– MAINT LED → lights up yellow: The H system is not in the RUN-Redundant system
– ERROR-LED → lights up red: Module failed
• Backup CPU → failed
S7-1500R/H redundant system
System Manual, 01/2024, A5E41814787-AF
Primary CPU
Backup CPU → failed
CP 1543-1 (at primary CPU) → failed
CP 1543-1 (at backup CPU)
PROFINET cable (PROFINET ring)
Two fiber-optic cables (redundancy connections)
S7-1500H failure of the CP 1543-1 at the primary CPU and backup CPU
state; no partner CPU was found.
Application planning
6.5 Failure scenarios
225