Startup Operating State; Error-Search Mode; Unexpected Error" Operating State - Siemens SIMATIC S7-4100 Equipment Manual

Diagnostic options and service support
5.1 Operating states of the CPU
You can load user programs from the engineering station to the CPU.
Note
The controller can only leave the STOP operating state with a loaded configuration.
5.1.4

STARTUP operating state

Behavior of the CPU
During STARTUP, the CPU leaves the STOP state. At the end of STARTUP, the controller should be
in RUN.
Note
If the loaded configuration is faulty, the CPU cannot reach the RUN state and reverts to the STOP
operating state.
5.1.5

ERROR-SEARCH mode

Behavior of the CPU
If the CPU is in the ERROR-SEARCH operating state, all communication connections are
interrupted. The controller is not accessible via the engineering station.
The ERROR-SEARCH operating state is indicated by the flashing RUN and STOP LEDs; see
section Overview of the LED displays (Page 35).
Troubleshooting mode runs when the following applies:
• The operator triggers "Reset to factory settings".
• The CPU has detected an error via the internal monitoring of the CPU.
5.1.6

"Unexpected error" operating state

The CPU always executes a self-test.
Possible reaction to an unexpected error:
• An unexpected error is detected:
The CPU tries to correct the error with an automatic restart.
• Repeated unexpected error within 24 hours:
No restart is enabled. The CPU remains in "Unexpected error" mode.
All LEDs flash.
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Equipment Manual, 11/2022, A5E51584364-AA
CPU 4168-H