Loss Of Redundancy Cpu - Siemens SIMATIC S7-1500 System Manual

⑪STARTUP → STOP
Transition Description
System state STARTUP → STOP
transition
The redundant system switches from the STARTUP system state to the STOP
system state if:
Primary CPU op-
• The primary CPU detects an error during startup that prevents further
erating state
processing
transition
or
• You set the primary CPU to STOP with the PG/PC, the display or the mode
selector
or
• The primary CPU processes a STOP command in startup OB
or
• In the CPU properties, you have set the following for startup behavior:
–
–
The primary CPU switches to STOP.
12.4.8

Loss of redundancy CPU

Introduction
In the case of failure or STOP operating state of a CPU in S7-1500R/H the redundant system
changes from RUN-Redundant system state to RUN-Solo system state. The operating system
calls the OB 72 "CPU redundancy error". The OB 82 is also called for the central modules (e.g.
CPs) of the failed CPU.
The redundancy loss due to failure/switching to STOP of the CPU is considered (CPU
redundancy error) in the following section. The system and operating state transitions ⑦
from the section System and operating state transitions (Page 400) are explained in more
detail:
• RUN-Redundant → RUN-Solo
• RUN-Redundant → RUN
Note
Loss of redundancy of I/O
If a loss of redundancy occurs in S7-1500H in the system state RUN-Redundant at a
redundant R1/S2 device, then one AR of two ARs of a R1/S2 device has failed. The operating
system calls the OB 70 "I/O redundancy error". You can find more information in the
Programming the S7-1500R/H (Page 317) section.
S7-1500R/H redundant system
System Manual, 01/2024, A5E41814787-AF
Too short a configuration time for the distributed I/O and
"Startup CPU only if compatible"
Commissioning
12.4 Operating and system states
Effects
This system state tran-
sition does not have
any effect on data.
This operating state
transition does not
have any effect on
data.
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