Leds For Cpu Functionality - Siemens SIMATIC IM 151/CPU Manual

Meanings of the LEDs for CPU Functionality
For the CPU component of the IM 151/CPU there are 2 separate LEDs that
indicate the operating modes of the CPU:
RUN
HALT
STOP
You can obtain information on the power supply of the CPU, on force requests and
on general errors via 3 additional LEDs.
Table 5-3

LEDs for CPU Functionality

LED Description
ON (green) Power up
RUN (green) RUN mode
STOP STOP mode
(yellow)
FRCE (yellow) Force job active
SF (red) Group error
Meanings of Other LEDs
The LEDs "SF" (from the PROFIBUS-DP viewpoint) and "BF" are described in
Section 4.4.
ET 200S Interface Module IM 151/CPU
A5E00058783-01
Comes on when the supply voltage is applied to the CPU
Shines continuously when the CPU component is processing
the user program.
Flashes at 2 Hz during startup of the CPU component:
For at least 3 secs, but the startup of the CPU component can
also be shorter.
During the startup of the CPU component, the STOP LED also
lights up; when the STOP LED goes off, the outputs are
enabled.
Flashes at 0.5 Hz when the CPU has reached a breakpoint you
have set. At the same time the STOP LED comes on
Comes on when the CPU component:
Is not processing a user program
Has reached a breakpoint you have set At the same time the
RUN LED flashes at 0.5 Hz
Flashes at 0.5Hz, when the CPU component requests a memory
reset (see Section 4.2)
Lights up when a force request is active
Lights up in the event of
Programming errors
Parameter assignment errors
Calculation errors
Timing errors
I/O errors
Hardware errors
Firmware errors
To determine the exact nature of the error/fault, you have to use a
programming device and read out the contents of the diagnostic
buffer.
Functions of the IM 151/CPU
Description
5-5