Ways To Reset The Memory; Resetting The Memory Of The Im 151-7 Cpu - Siemens SIMATIC ET 200S Manual

Commissioning and Diagnostics
7.2

Resetting the memory of the IM 151-7 CPU

When do you reset the memory of the IM 151-7 CPU?
The memory of the IM 151-7 CPU must be reset
S to erase retentive areas (memory markers, times, counters)
S if the IM 151-7 CPU requests a memory reset by flashing the STOP LED at
0.5 Hz
The following are possible reasons for the MRES request:
S The ET 200S is starting up for the first time.
S Inconsistent memory areas
S The memory module (MMC) has been replaced.
How do you reset the memory?
There are two ways of resetting the IM 151-7 CPU:
Table 7-2
Resetting the memory with the mode
selector
Described in this chapter.
Resetting the memory of the IM 151-7 CPU with the mode selector
To reset the memory of the IM 151-7 CPU using the mode selector, proceed as
follows (see also Figure 7-1):
1. Switch the mode selector to the STOP position.
2. Depress the mode selector in the MRES position. Hold the mode selector at
this position until the STOP LED lights up for the second time (3 seconds) and
then let it return to the STOP position.
3. Within 3 seconds, you must press the mode selector back to the MRES position
and hold it in this position until the STOP LED flashes rapidly (at 2 Hz). When
the IM 151-7 CPU has completed the memory reset, the STOP LED stops
flashing and remains on.
The IM 151-7 CPU has reset the memory.
7-4

Ways to reset the memory

Resetting the memory with the PD
Only possible during CPU STOP (see the
PD manuals and the STEP 7 Online Help)
ET 200S IM 151-7 CPU Interface Module
A5E00058783-04