Siemens SIMATIC S7-1500 System Manual page 175

N o . Op e rating mode transitions
③ STOP →
STARTUP
④
STARTUP →
STOP
⑤
STARTUP →
RUN
⑥
RUN → STOP
Automation system
System Manual, 09/2016, A5E03461182-AD
The CPU switches to "STARTUP" mode if:
The hardware configuration and program
•
blocks are consistent.
You set the CPU to "RUN" mode via the
•
programming device or the display and
the mode switch in is RUN position.
or
You set the mode switch from STOP to
•
RUN.
The CPU returns to the "STOP" mode in the
following cases of "STARTUP":
The CPU detects an error during startup.
•
You set the the CPU to "STOP" via the
•
programming device, display or mode
selector.
A STOP command is executed in the
•
Startup OB.
The CPU goes to the "RUN" mode in the
following cases of "START-UP":
The CPU has initialized the PLC tags.
•
The CPU has executed the startup
•
blocks successfully.
The CPU returns to the "STOP" mode in the
following cases of "RUN":
An error is detected that prevents con-
•
tinued processing.
A STOP command is executed in the
•
user program.
You set the the CPU to "STOP" via the
•
programming device, display or mode
selector.
10.5 Operating modes of the CPU
Effects
Non-retentive memory is cleared, and the content
of non-retentive DBs is reset to the start values of
the load memory. Retentive memory and reten-
tive DB contents are retained.
Commissioning
175