Switch To Cpu With Modified Configuration Or Expanded Memory Configuration - Siemens SIMATIC S7-400H System Manual

Link-up and update
12.3 Link-up and update sequence
12.3.3

Switch to CPU with modified configuration or expanded memory configuration

Switch to CPU with modified configuration
You may have modified the following elements on the reserve CPU:
● The hardware configuration
● The type of load memory. You may have replaced a RAM card with a FLASH card, for
For information on steps required in the scenarios mentioned above, refer to section Failure
and replacement of components during operation (Page 265).
Note
Even though you have not modified the hardware configuration or the type of load memory
on the reserve CPU, there is nevertheless a master/reserve changeover and the previous
master CPU changes to STOP.
Note
If you have downloaded connections using NETPRO, you can no longer change the memory
type of the load memory from RAM to FLASH.
When you initiate a link-up and update operation with the "Switch to CPU with modified
configuration" option in STEP 7, the system reacts as follows with respect to handling of the
memory contents.
Load memory
The contents of the load memory are not copied from the master to the reserve CPU.
Work memory
The following components are transferred from the work memory of the master CPU to the
reserve CPU:
● Contents of all data blocks assigned the same interface time stamp in both load
● Data blocks generated in the master CPU by SFCs.
● Process images, timers, counters, and bit memories
If there is insufficient memory, link-up is cancelled with an entry in the diagnostic buffer.
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example. The new load memory may be larger or smaller than the old one.
memories and whose attributes "read only" and "unlinked" are not set.
The DBs generated in the reserve CPU by means of SFC are deleted.
If a data block with the same number is also found in the load memory of the reserve
CPU, link-up is cancelled with an entry in the diagnostic buffer.
System Manual, 03/2012, A5E00267695-11
S7-400H