Siemens SIMATIC S7-300 Reference Manual page 5

Loading objects to the CPU
The table shows which changes and which changed blocks can be loaded in which operating mode.
Very complex programs can prevent loading in RUN mode. Possible solutions:
• Use a memory card with sufficient capacity.
• Select a CPU with sufficient work memory.
• Reduce the number of changed used blocks, constants, PLC tags or data types.
Changes and blocks
Changed properties of HW
components
Added HW components
New/changed text lists
(Alarms)
Download number of blocks
Download PLC program to
device and reset
New OB
Changed OB: Code changes,
change of comments
OB with changed properties
(e.g. cycle time change)
Deleted OB
A5E33285102-AB
S7-300 S7-400
STOP STOP
STOP STOP
RUN RUN
RUN (<17) RUN (<57)
STOP STOP
(Reset) (Reset)
RUN RUN
RUN RUN
RUN RUN
RUN RUN
S7-1200 S7-1500
as of V4.0 V1.7
STOP STOP
STOP STOP
STOP STOP
RUN (<21) RUN
STOP STOP
(Reset) (Reset)
STOP RUN
RUN RUN
STOP RUN
STOP RUN
S7-1200 S7-1200
V1.0 - 2.1 V2.2 - V3.0
STOP STOP
STOP STOP
STOP STOP
STOP RUN (<11)
STOP STOP
(Reset) (Reset)
STOP STOP
STOP RUN
STOP STOP
STOP STOP
S7-1500
V1.0-V1.6
STOP
STOP
STOP
RUN
STOP
(Reset)
RUN
RUN
RUN
RUN
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