Siemens SIMATIC S7-1500 System Manual page 220

Failure scenario
①
②
③
④
⑤
⑥
⑦
⑧
⑨
⑩
Figure 6-57
Sequence of events
1. The left interface module (slot 0) of the R1 device fails in PROFINET ring 1 and interrupts
PROFINET ring 1.
2. The redundant system selects an alternative connection over the backup CPU and the
PROFINET ring 2. This allows the redundant system to access the R1 device (via the right-
hand interface module at slot 1).
3. In addition, the PROFINET line from the right interface module (slot 1) to the backup CPU
fails.
4. The redundant system selects an alternative connection via the backup CPU over PROFINET
ring 2. This allows the redundant system to access the R1 device (via the right-hand
interface module at slot 1).
S7-1500R/H redundant system
System Manual, 01/2024, A5E41814787-AF
Primary CPU
Backup CPU
Two fiber-optic cables (redundancy connections)
PROFINET cable (PROFINET ring 1)
PROFINET cable (PROFINET ring 2)
PROFINET line → interrupted (2nd defect)
IO device ET 200SP HA
IO device ET 200SP
ET 200SP HA interface module → failed (1st defect)
PROFINET line → interrupted (3rd defect)
Failure of an interface module in an R1 device and of the PROFINET lines in two places of
a PROFINET ring.
Application planning
6.5 Failure scenarios
219