Possible Causes Of A Cpu Request To Reset Memory - Siemens SIMATIC S7-300 Hardware And Installation Manual

Commissioning
Table 8-3
Causes of a CPU request to reset
The Memory Card or MMC has been
replaced.
RAM error in CPU
Main memory too small, that is not all
user program blocks on a Memory
Card or MMC could be loaded.
Attempts to load faulty blocks; e.g. if
the wrong instruction was
programmed.
How to reset memory
There are two ways of resetting CPU memory:
Memory reset with the mode selector
... is described in this Chapter.
8-14

Possible causes of a CPU request to reset memory

memory
switch
S7-300 Programmable Controller Hardware and Installation
Remarks
not with CPU 312 IFM /
314 IFM (314-5AE0x)
–
CPU with inserted 5-V FEPROM Memory Card
(not CPU 31x)
With these causes the CPU requests one
memory reset. After that, the CPU ignores the
contents of the memory card, enters the error
reasons in the diagnostics buffer and goes to
STOP. You can erase or reprogram 5-V
FEPROM Memory Card in the CPU.
CPU 31xC with inserted MMC: Continuous
request to reset memory.
Additional information on MMC behavior after
memory reset is found in the Reference Manual
CPU Data , Chapter memory Conception.
Memory reset with PG
... only possible if the CPU is in STOP mode
(seeSTEP 7 Online Help).
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