Performance data / operation   
5.7 Memory organization 
  CP 343-1 ERPC 
34  Manual, 03/2010, C79000-G8976-C239-02 
 
 
Note 
Recommendation for data storage 
If you use the CP in a complex plant configuration, the configuration data can become 
extensive. In such cases, the time for the transfer of the configuration data from the CPU to 
the CP may take several minutes. 
In such cases, you should weigh up the pros and cons of storing the data on the CP. 
 
Meaning of the memory areas 
On the CP 343-1 ERPC, the file system is divided into the following areas: 
●  Fixed data 
The MAC address is stored permanently in the this part of internal memory. 
●  C-PLUG 
The C-PLUG is nonvolatile memory. It consists of the following areas: 
–  Retentive area 
The retentive area includes the storage of the IP parameters, LAN settings and the 
modifiable SNMP variables safe from power outages. 
If you reset memory, the data is retained. 
If you reset to the factory settings, this area is erased. 
–  Flash area - internal file system 
The flash file system is used to store the ILS license file and backup copy of the ILS 
Workbench configuration so that they are safe from power outages. 
If you reset memory, the data is retained. 
If you reset to the factory settings, this area is erased. 
–  Flash area - STEP 7 configuration data 
The STEP 7 configuration data is located here (alternatively: storage of the 
configuration data on the CPU). 
If you reset memory or reset to factory settings, this area is erased. 
 
NOTICE 
 
 
Number of write cycles 
The C-PLUG uses flash components and only allows a limited number of write cycles 
(approximately 100 000). You should therefore avoid continuous cyclic writing of data 
(for example changing IP parameters with FB55) to the C-PLUG.