Siemens SINUMERIK 840D sl Function Manual page 1295

2.4.5 Data backup
The PLC-CPU does not save any symbolic names, but instead data type descriptions of the
block parameters:
• VAR_INPUT, VAR_OUTPUT, VAR_IN_OUT, VAR and
• the data types of the global data blocks.
If the STEP7 project exists and has been created according to the instructions given above,
then symbols can be processed in the PLCCPU on this machine. It may also be advisable to
store the machine source programs as AWL files in case they are required for any future
upgrade.
The source programs of all organization blocks and all instance data blocks should always
be available.
2.4.6 PLC series start-up, PLC archives
Once the blocks have been loaded to the PLC CPU, a series archive can be generated via
the HMI operator interface to back up data on the machine. To ensure data consistency, this
backup must be created immediately after block loading when the PLC is in the Stop state. It
does not replace the SIMATIC project backup as the series archive saves binary data only,
and does not back up, e.g., symbolic information. In addition, no CPU DBs (SFC 22 DBs) or
SDBs generated in the CPU are saved.
The PLC series archive can be generated directly from the relevant SIMATIC project as an
alternative.
To do this, select the "Options" → "Settings" menu item and the "Archive" tab in STEP7. This
contains an entry "SINUMERIK (*.arc)", which must be selected to create a series
commissioning file. After selection of the archive, select the "File" → "Archive" menu item.
The relevant series archive will then be generated. If the project contains several programs,
the program path can be selected. A series archive is set up for the selected program path.
All blocks contained in the program path are incorporated into the archive, except for CPU-
DBs (SFC 22 DBs).
Basic logic functions: PLC basic program solution line (P3 sl)
Function Manual, 11/2006, 6FC5397-0BP10-2BA0
Note
No sensible recompilation is possible without the related project for this machine. This
especially affects, for instance the function status of the block or the necessary changes
done in the PLC-CPU programs later. It is, therefore, necessary to keep a backup copy of
the STEP7 project located in the PLC CPU on the machine. This is a great help for the
service case and saves unnecessary consumption of time in restoring the original project.
Detailed description
2.4 Starting up the PLC program
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