Siemens SIMATIC S7-400H, Системное руководство

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Assembly of a CPU 41x–H
5.3 Status and error displays
S7-400H
System Manual, 03/2012, A5E00267695-11
55
5.3 Status and error displays
RUN and STOP LEDs
The RUN and STOP LEDs provide information about the currently active CPU operating
status.
LED Meaning
RUN STOP
Lit Dark The CPU is in RUN mode.
Dark Lit The CPU is in STOP mode. The user program is not being executed. Cold
restart/restart is possible. If the STOP status was triggered by an error, the error
indicator (INTF or EXTF) is also set.
Flashes
2 Hz Flashes
2 Hz CPU is DEFECTIVE. All other LEDs also flash at 2 Hz.
Flashes
0.5 Hz Lit HOLD status has been triggered by a test function.
Flashes
2 Hz Lit A cold restart/restart was initiated. The cold restart/warm start may take a minute or
longer, depending on the length of the called OB. If the CPU still does not change to
RUN, there might be an error in the system configuration, for example.
Dark Flashes
2 Hz A high-quality RAM test (self-test) is executed after POWER ON. The self-test takes at
least 10 minutes.
Memory is being reset
Irrelevant Flashes
0.5 Hz The CPU requests a memory reset.
Flashes
0.5 Hz Flashes
0.5 Hz Troubleshooting mode
This display also indicates that internal processes are busy on the CPU and prevent
access to the CPU until completed. This status can be triggered by the following
routines:

Startup (POWER ON) of a CPU on which a large number of blocks is loaded. If
encrypted blocks are loaded, startup may take a longer time depending on the
number of such blocks.
 Memory reset after you have inserted a large Memory Card, or if there are
encrypted blocks.