Siemens SIMATIC S7-1500 System Manual page 407

Commissioning
12.4 Operating and system states
④STARTUP → RUN-Solo, STARTUP → RUN
Transition Description
System state STARTUP → RUN-Solo
transition
The redundant system switches from STARTUP to the RUN-Solo system state if:
• The primary CPU has initialized the PLC tags
and
• The primary CPU has executed the startup blocks successfully
and
• "Startup CPU only if compatible" is configured, there is feedback from all IO
devices before the end of the configuration time and all IO devices match
the configured hardware configuration or "Startup CPU even if mismatch"
is configured and the configuration time is up.
The backup CPU remains in STOP.
Operating state STARTUP → RUN
transition
The primary CPU switches to the RUN operating state if:
• The CPU has initialized the PLC tags;
• The CPU has executed the startup blocks successfully;
and
• "Startup CPU only if compatible" is configured, there is feedback from all IO
devices before the end of the configuration time and all IO devices match
the configured hardware configuration or "Startup CPU even if mismatch"
is configured and the configuration time is up.
406
Effects
The process image is
updated and pro-
cessing of the cyclic
user program begins.
The outputs of the IO
devices are initialized.
S7-1500R/H redundant system
System Manual, 01/2024, A5E41814787-AF