Operating State Transitions - Siemens SIMATIC S7-1500 System Manual

Commissioning
13.4 Operating states of the CPU
13.4.5

Operating state transitions

Operating states and operating state transitions
The figure below shows the operating state and operating state transitions:
Figure 13-2
The table below shows the effects of operating state transitions:
Table 13- 1 Operating state transitions
No. Operating state transitions
① POWER ON →
STARTUP
② POWER ON → STOP
276
Operating states and operating state transitions
After switching on, the CPU switches to "STARTUP" if:
• The hardware configuration and program blocks are
consistent.
• The preceding "POWER OFF" was triggered by an
interruption in the power supply.
• Startup type "Warm restart - RUN" is set.
or
• Startup type "Warm restart mode before POWER
OFF" is set and the CPU was in RUN mode before
POWER OFF.
After switching on, the CPU switches to "STOP" if:
• The hardware configuration and program blocks are
inconsistent.
or
• Startup type "No restart" is set.
or
• Startup type "Warm restart mode before POWER
OFF" is set and the CPU was in STOP mode before
POWER OFF.
Effects
The CPU clears the non-retentive
memory, and resets the content
of non-retentive DBs to the start
values of the load memory. Reten-
tive memory and retentive DB
content are retained.
The 500 most recent entries are
retained in the diagnostics buffer.
The CPU clears the non-retentive
memory, and resets the content
of non-retentive DBs to the start
values of the load memory. Reten-
tive memory and retentive DB
content are retained.
The 500 most recent entries are
retained in the diagnostics buffer.
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System Manual, 11/2023, A5E46600094-AD