Siemens Simantic S7-1500 Manual page 35

Meaning of the RUN/STOP, ERROR and MAINT LEDs
The CPU 1517T-3 PN/DP 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
LED off
LED off
LED lit green
LED lit green
LED lit green
LED lit green
LED lit green
LED lit yellow
LED lit yellow
LED lit yellow
LED lit yellow
LED flashes yellow
LED flashes
yellow/green
CPU 1517T-3 PN/DP (6ES7517-3TP00-0AB0)
Manual, 12/2017, A5E36285525-AB
ERROR LED
LED off
LED flashes red
LED off
LED flashes red
LED off LED lit yellow
LED off
LED flashes yellow
LED flashes red
LED flashes red
LED off
LED flashes yellow
LED off
LED flashes red LED flashes yellow
LED off
LED off
Interrupts, error messages, diagnostics and system alarms
4.1 Status and error displays of the CPU
MAINT LED
Missing or insufficient supply voltage on the CPU.
LED off
An error has occurred.
LED off
CPU is in RUN mode.
LED off
A diagnostics event is pending.
LED off
Maintenance demanded for the plant.
The affected hardware must be checked/replaced
within a short period of time.
Active Force job
PROFIenergy pause
Maintenance required for the plant.
The affected hardware must be checked/replaced
within a foreseeable period of time.
Bad configuration
An error has occurred.
LED off
LED off
Firmware update successfully completed.
CPU is in STOP mode.
LED off
The program on the SIMATIC memory card is
causing an error.
CPU defective
CPU is performing internal activities during STOP,
e.g. startup after STOP.
LED off
Download of the user program from the SIMATIC
memory card
CPU carries out a program with active breakpoint.
Startup (transition from RUN → STOP)
LED off
Meaning
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