Siemens SIMATIC S7-1500 System Manual page 284

Commissioning
11.4 Operating and system states
Procedure:
1. POWER OFF/POWER ON the backup CPU. Result: The CPU becomes the backup CPU again
and changes to STOP.
2. POWER OFF/POWER ON the primary CPU. Result: The CPU changes to RUN. The redundant
system switches to the RUN-Solo system state.
3. Switch the backup CPU to POWER OFF/POWER ON again. Result: The redundant system
switches to the SYNCUP system state.
②
No STARTUP after parameterization "Warm restart - operating mode before POWER
OFF"
Requirements:
• You have parameterized "Warm restart - operating mode before POWER OFF" for both
CPUs.
• The redundant system is in the RUN-Redundant system state.
Procedure:
1. POWER OFF both CPUs at the same time.
2. Set the mode selector for the primary CPU to STOP.
3. POWER ON both CPUs again. Result: The redundant system switches to the STOP system
state.
②
POWER ON → STOP
Transition Description
System state trans­ POWER ON → STOP
ition The redundant system switches to the STOP system state after switch-on if:
• The CPUs have different firmware versions
Operating state
or
transitions
• The mode selector is in the STOP position
or
• The hardware configuration and program blocks are inconsistent
or
• The startup type "No restart (remain in STOP)" is set
or
• The startup type "Warm restart - Operating mode before POWER OFF" is set
and the redundant system was in STOP before POWER OFF.
③
STOP → STARTUP
Transition Description
System state trans­ STOP → STARTUP
ition The redundant system switches to the STARTUP system state if:
• You set a CPU to RUN via the PG/PC or the display and the mode selector is
set to RUN
or
• You set the mode switch from STOP to RUN.
284
Effects
The primary CPU clears
the non-retentive
memory and resets the
contents of non-retent­
ive data blocks to the ini­
tial values of the load
memory. Retentive
memory and retentive
DB contents are
retained.
Effects
The primary CPU clears
the non-retentive
memory and resets the
contents of non-retent­
ive data blocks to the ini­
tial values of the load
memory. Retentive
memory and retentive
S7-1500R/H redundant system
System Manual, 11/2022, A5E41814787-AD