Siemens Simantic ET200SP - Page 216

Commissioning
10.6 Operating modes of the CPU
Distributed I/O system
216 System Manual, 12/2016, A5E03576849-AG
The table below shows the effects of the operating mode transitions:
Table 10- 7 Operating mode transitions
No.
Operating mode transitions
Effect
①
POWER ON →
STARTUP
After switching on, the CPU switches to "STARTUP"
mode if:
•
The hardware configuration and program blocks are
consistent.
• The "Warm restart-RUN" startup type is set
or
• The "Warm restart mode before POWER OFF" is
set and was in RUN mode before POWER OFF.
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 retentive DB con-
tents are retained.
②
POWER ON →
STOP
After switching on, the CPU goes to "STOP" mode if:
•
The hardware configuration and program blocks are
inconsistent
or
• The "No restart" startup type is set.
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 retentive DB con-
tents are retained.
③
STOP → STARTUP The CPU switches to "STARTUP" mode if:
•
The hardware configuration and program blocks are
consistent.
• The programming device sets the CPU to "RUN"
and the mode selector is in the RUN setting
or
• The mode selector is switched from STOP to RUN.
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 retentive DB con-
tents are retained.
④
STARTUP → STOP The CPU returns to the "STOP" mode in the following
cases of "STARTUP":
• The CPU detects an error during startup.
• The programming device or the mode selector sets
the CPU to "STOP".
• A STOP command is executed in the Startup OB.
⑤
STARTUP → RUN 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 success-
fully.
⑥
RUN → STOP The CPU returns to the "STOP" mode in the following
cases of "RUN":
• An error is detected that prevents continued pro-
cessing.
• A STOP command is executed in the user program.
• The programming device or the mode selector sets
the CPU to "STOP".