Stop Operating State - Siemens SIMATIC S7-1500 System Manual

Commissioning
12.4 Operating and system states
Note
"Comparison preset to actual configuration" parameter for communications processors
and active backplane bus
The parameter "Comparison preset to actual configuration" can also be set for
communications processors and active backplane bus in STEP 7. In addition, you can take
over the set "Comparison preset to actual configuration" parameter for the start-up from the
CPU (recommended setting):
• From CPU (recommended setting)
• Startup CPU only if compatible
• Startup CPU even if mismatch
The parameter is only evaluated in the STARTUP operating state.
12.4.3

STOP operating state

Response
The CPU does not execute the user program in the STOP operating state.
All outputs are disabled or respond as configured for the given module if both CPUs are in
STOP operating state: They provide a configured substitute value or retain the last value
output and thus hold the controlled process in a safe operating state.
Points to note
The backup CPU establishes no connections to the IO devices in the STOP operating state.
The primary CPU establishes connections to the IO devices in the STOP operating state. The
primary CPU activates the system IP address even in the STOP operating state if the system IP
address has been configured.
If both CPUs are in STOP and you download a configuration to one CPU, note the following:
• You have not downloaded a configuration to the backup CPU and the backup CPU should
become the primary CPU:
Switch the backup CPU to the primary CPU (either in the event dialog of the download
process or via the mode switch of the CPU).
• Downloading to the primary CPU configures the connected IO devices in line with the
downloaded hardware configuration, even in STOP operating state.
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S7-1500R/H redundant system
System Manual, 01/2024, A5E41814787-AF