Siemens S7-300 - 8.5 SM 326; DO 8 x DC 24 V;2 A PM

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S7-300 Automation System, Hardware and Installation: CPU 312IFM - 318-2 DP
A5E00203919-01
9-15
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With a CPU 318-2DP you can also perform a cold start instead of resetting the
memory.
Cold start means:
• The data blocks in the working memory created by SFC 22 are deleted. The
remaining data blocks have the default value from load memory.
• The process image and all timers, counters and memory bits are reset -
irrespective of whether they were configured as retentive.
• OB 102 is processed.
• The process image of the inputs is read before the first instruction in OB1 is
executed.
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1. Turn the key to STOP position
2. Turn the key to MRES position
Hold the key in this position until the STOP LED lights up for the second time
and remains on (this takes 3 seconds).
Then release the key.
3. You have to turn the switch to the RUN position within 3 seconds.
During start-up the RUN LED flashes at 2 Hz.
t
On
STOP
LED
Off
3s
max. 3 s
3s
On
RUN
LED
Off
1
2
3
Figure 9-8 Using the mode selector switch for a cold start (CPU 318-2 DP only)