Memory Requirements For Downloading Software Changes - Siemens S7-1500 Function Manual

Memory areas and retentive memory

2.6 Memory requirements for downloading software changes

2.6 Memory requirements for downloading software changes
Memory requirements in RUN state
For the consistent and atomic execution of the complete download operation, the CPU
requires adequate free memory space in the work memory and on the SIMATIC memory
card. The files affected by loading the software changes to the CPU are only deleted after
the new files have been created. This SIMATIC memory card therefore requires free memory
space corresponding approximately to the space required for all program objects to be
loaded on the memory card.
If this amount of memory is not available on your SIMATIC memory card, the following
message is displayed in STEP 7 during the download operation to the CPU: "There is
insufficient memory on the memory card for this amount of data."
In order to still enable the loading of changes to the CPU in such a case, we recommend one
or more of the following options:
● Download in RUN state
– Delete any files no longer required (e.g. CSV files, panel backups, etc.) on the
– Preferably, you should download extensive changes in RUN state in multiple steps or
● Download in STOP state
– If downloading in several steps is not possible, load extensive changes in STOP state.
● Use a larger memory card
– In order to perform extensive downloads in RUN state of the CPU in the future, use a
Impact of minor program changes on the load procedure
Under the objects of a program, there are dependencies, e.g.
● Of code blocks to called code blocks
● Of code blocks to data blocks
● Of data blocks to data types (PLC data types, FB types)
This means that the load procedure for a minor change may be very time-consuming if the
change affects a large number of dependent objects.
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memory card using the Web server.
perform the download after each change step.
Note that when loading in STOP state, the actual values of non-retentive data are not
initialized.
larger memory card. A description of how to change the memory card can be found in
the section "Changing the memory card without loss of retentive data".
Structure and Use of the CPU Memory
Function Manual, 10/2018, A5E03461664-AC