Siemens CPU 31 Series - Changed Retentive Behavior for Cpus with Firmware >= V2.1.0; Fms;Cps with Separate MPI Address in the Central Rack of a CPU 315-2 PN;DP, a CPU 317 or a CPU 319-3 PN;DP

Appendix
A.1 Information about upgrading to a CPU 31xC or CPU 31x
CPU 31xC and CPU 31x, Technical Data
A-8 Manual, 01/2006 Edition, A5E00105475-06
A.1.12 Changed retentive behavior for CPUs with firmware >= V2.1.0
Changed retentive behavior for CPUs with firmware >= V2.1.0
For data blocks for these CPUs
• you can set the retentive response in the block properties of the DB.
• Using SFC 82 "CREA_DBL" -> Parameter ATTRIB, NON_RETAIN bit, you can specify if
the actual values of a DB should be maintained at POWER OFF/ON or STOP-RUN
(retentive DB) or if the start values should be read from the load memory (non-retentive
DB).
A.1.13 FMs/CPs with separate MPI address in the central rack of a CPU 315-2 PN/DP, a
CPU 317 or a CPU 319-3 PN/DP
FMs/CPs with separate MPI address in the central rack of a CPU 315-2 PN/DP / CPU 317 /
CPU 319-3 PN/DP
All CPUs except CPU 315-2 PN/DP, CPU 317,
CPU 318-2 DP and CPU 319-3 PN/DP
CPU 315-2 PN/DP, CPU 317 ,CPU 318-2 DP and
CPU 319-3 PN/DP
If there are FM/CPs with their own MPI address in the
central rack of an S7-300, then they are in the exact same
CPU subnet as the CPU MPI station.
If there are FM/CPs with their own MPI address in the
central rack of an S7-300, then the CPU forms its own
communication bus via the backplane bus with these
FM/CPs, which are separated from the other subnets.
The MPI address of such an FM/CP is no longer relevant for
the stations on other subnets. The communication to the
FM/CP is made via the MPI address of the CPU.
When exchanging your existing CPU with a CPU 315-2 PN/DP / CPU 317 /
CPU 319-3 PN/DP, you therefore need to
• replace the CPU in your STEP 7 project with the CPU 315-2 PN/DP / CPU 317 /
CPU 319-3 PN/DP
• Reconfigure the OPs. The control and the destination address must be reassigned (= the
MPI address of the CPU 315-2 PN/DP / CPU 317
CPU 319-3 PN/DP and the slot of the respective FM)
• Reconfigure the project data for FM/CP to be loaded to the CPU.
This is required for the FM/CP in this rack to remain "available" to the OP/PG.