Siemens Simatic S7-300 CPU 31xC and CPU 31x S7-300 - Manual (Page 214)

Appendix
A.1 Information about upgrading to a CPU 31xC or CPU 31x
CPU 31xC and CPU 31x, Technical data
A-8
Manual, Edition 08/2004, A5E00105475-05
A.1.9 Load memory concept for the CPU 31xC/31x
Load memory concept for the CPU 31xC/31x
On CPUs 312 IFM to 318-2 DP, the load memory is integrated into the CPU and may be
extended with a memory card,
The load memory of the CPU 31xC/31x is located on the micro memory card (MMC), and is
retentive. When blocks are downloaded to the CPU, they are stored on the MMC and cannot
be lost even in the event of a power failure or memory reset.
Reference
See also the Memory concept chapter in the CPU Data 31xC and 31x manual.
Note
User programs can only be downloaded and thus the CPU can only be used if the MMC is
inserted.
A.1.10 PG/OP functions
PG/OP functions
With CPUs 315-2 DP (6ES7315-2AFx3-0AB0), 316-2DP and 318-2 DP, PG/OP functions at
the DP interface were only possible if the interface was set to active. With CPUs 31xC/31x,
these functions are possible at both active and passive interfaces. The performance of the
passive interface is considerably lower, however.
A.1.11 Routing for the CPU 31xC/31x as an intelligent slave
Routing for the CPU 31xC/31x as an intelligent slave
If you use the CPU 31xC/31x as an intelligent slave, the routing function can only be used
with an actively-configured DP interface.
In the properties of the DP interface in STEP 7, select the "Test, Commissioning, Routing"
check box of the "DP-Slave" option.