Siemens Simatic S7-300 CPU 31xC and CPU 31x S7-300 - Manual (Page 168)

Technical data of CPU 31x
7.1 General technical data
CPU 31xC and CPU 31x, Technical data
7-2
Manual, Edition 08/2004, A5E00105475-05
7.1.2 Technical data of the Micro Memory Card (MMC)
Plug-in SIMATIC Micro Memory Cards
The following memory modules are available:
Table 7-1 Available MMCs
Type Order number Required for a firmware update via MMC
MMC 64k 6ES7 953-8LFxx-0AA0 –
MMC 128k 6ES7 953-8LGxx-0AA0 –
MMC 512k 6ES7 953-8LJxx-0AA0 –
MMC 2M 6ES7 953-8LLxx-0AA0 Minimum requirement for CPUs without DP interface
MMC 4M 6ES7 953-8LMxx-0AA0 Minimum requirement for CPUs with DP interface
MMC 8M 1 6ES7 953-8LPxx-0AA0 –
1 This MMC cannot be used together with CPU 312C or CPU 312.
Maximum number of loadable blocks in the MMC
The number of blocks that can be stored on the MMC depends on the capacity of the MMC
being used. The maximum number of blocks that can be loaded is therefore limited by the
capacity of your MMC (including blocks generated with the "CREATE DB" SFC):
Table 7-2 Maximum number of loadable blocks on the MMC
Size of MMC Maximum number of blocks that can be loaded
64 KB 768
128 KB 1024
512 KB
2 MB
4 MB
8 MB Here the maximum number of blocks that can be loaded for the
specific CPU is less than the number of blocks that can be stored on
the MMC.
Refer to the corresponding specifications of a specific CPU to
determine the maximum number of blocks that can be loaded.