Siemens CPU 1518-4 PN/DP ODK - Page 34

Interrupts, error messages, diagnostics and system alarms
4.1 Status and error display of the CPU
CPU 1518-4 PN/DP ODK (6ES7518-4AP00-3AB0)
34 Manual, 09/2016, A5E35681108-AA
Meaning of the RUN/STOP, ERROR and MAINT LEDs
The CPU 1518-4 PN/DP ODK has three LEDs to signal the current operating status and
diagnostics status. The following table shows the meaning of the various combinations of
colors for the RUN/STOP, ERROR and MAINT LEDs.
Table 4- 1 Meaning of the LEDs
RUN/STOP LED
ERROR LED
MAINT LED
Meaning
LED off
LED off
LED off
Missing or insufficient power supply on
the CPU.
LED off
LED flashes red
LED off
An error has occurred.
LED lit green
LED off
LED off
CPU is in RUN mode.
LED lit green
LED flashes red
LED off
A diagnostics event is pending.
LED lit green LED off LED lit yellow
Maintenance demanded for the plant.
The affected hardware must be
checked/replaced within a short period of
time.
Active Force job
PROFIenergy pause
LED lit green LED off
LED flashes yel-
low
Maintenance required for the plant.
The affected hardware must be
checked/replaced within a foreseeable
period of time.
Bad configuration
LED lit yellow LED off
LED flashes yel-
low
Firmware update successfully complet-
ed.
LED lit yellow
LED off
LED off
CPU is in STOP mode.
LED lit yellow
LED flashes red
LED flashes yel-
low
The program on the SIMATIC memory
card is causing an error.
CPU defective
LED flashes yel-
low
LED off LED off
CPU is performing internal activities
during STOP, e.g. startup after STOP.
Download of the user program from the
SIMATIC memory card
LED flashes
yellow/green
LED off LED off
Startup (transition from RUN → STOP)
LED flashes
yellow/green
LED flashes red LED flashes yel-
low
Startup (CPU booting)
Test of LEDs during startup, inserting a
module.
LED flashing test