Siemens CPU 315-2 PN/DP - CPU Memory Reset and Restart

Memory concept
4.2 Memory functions
CPU 31xC and CPU 31x, Technical Data
Manual, 01/2006 Edition, A5E00105475-06
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4.2.4 CPU memory reset and restart
CPU memory reset
After the insertion/removal of a Micro Memory Card, a CPU memory reset restores defined
conditions for CPU restart (warm start). A CPU memory reset rebuilds the CPU's memory
management. Blocks in load memory are retained. All dynamic runtime blocks are
transferred once again from load memory to RAM, in particular to initialize the data blocks in
RAM (restore initial values).
Restart (warm start)
• All retentive DBs retain their actual value (non-retentive DBs are also supported by CPUs
with Firmware >= V2.1.0. Non-retentive DBs receive their initial values).
• The values of all retentive M, C, T are retained.
• All non-retentive user data are initialized:
– M, C, T, I, O with "0"
• All run levels are initialized.
• The process images are deleted.
Reference
Also refer to CPU memory reset by means mode selector switch in the section
Commissioning in the CPU 31xC and CPU 31x Operating Instructions .