How To Use The Mode Selector To Reset The Memory; Internal Cpu Events At Memory Resetting - Siemens SIMATIC ET 200S Manual

STOP
LED
On
Off
RUN RUN
STOP STOP
MRES MRES
1st 2.
Figure 7-1

How to use the mode selector to reset the memory

Is the STOP LED not flashing at memory resetting?
Does the STOP LED not flash during memory reset or do other indicators come
on? You must repeat steps 2 and 3. If the IM 151-7 CPU still doesn't execute a
memory reset, you have to read out the diagnostic buffer of the CPU with the PD
(see the STEP 7 user manual).
What happens in the IM 151-7 CPU?
Table 7-3

Internal CPU events at memory resetting

Event
Sequence of
operations in the
IM 151-7 CPU
Memory contents
after reset
What's left?
ET 200S IM 151-7 CPU Interface Module
A5E00058783-04
3 s
Max. 3 s
RUN RUN
STOP STOP
MRES MRES
3.
Response of the CPU in the IM 151-7 CPU
1. The CPU deletes the entire user program in the working memory
and the RAM load memory.
2. The CPU deletes the retentive data.
3. The CPU tests its own hardware.
4. If you have inserted a memory module (micro memory card =
MMC), the CPU copies the relevant contents of the module to
the working memory.
The CPU has the memory level "0". If a SIMATIC micro memory card
is inserted, the user program is transferred back into the working
memory.
The contents of the diagnostic buffer and the runtime meter.
Commissioning and Diagnostics
Min. 3 s
RUN
STOP
MRES
t
7-5