Siemens Simatic S7-1500 - Page 87

Interrupts, error messages and diagnostics and system alarms
9.1 Status and error display of the CPU
CPU 1505SP (F) Ready4Linux Version 2.7
Operating Instructions, 05/2019, A5E46864285-AA
87
Meaning of the LED displays
The CPU has three LEDs to indicate the current operating mode and diagnostic status. The
following table shows the meaning of the various combinations of colors for the RUN/STOP,
ERROR and MAINT LEDs.
Table 9- 1 Meaning of the LEDs
RUN/STOP
LED
ERROR LED
MAINT LED
Meaning
LED off
LED off
LED off
POWER OFF, the DIAG LED dis-
play is not enabled.
LED green
LED off
LED off
CPU is in RUN mode.
LED green
LED flashes
red
LED off
A diagnostics event is pending.
LED green LED off LED yellow
Maintenance demanded for the
plant.
The affected hardware must be
replaced within a short period of
time.
For fail-safe CPU:
Safety mode is deactivated.
LED green LED off
LED flashes
yellow
Maintenance required for the plant.
The affected hardware must be
replaced within a reasonable time
period.
LED green
LED flashes
red
LED off
An error has occurred.
LED yellow
LED flashes
red
LED off
LED yellow
LED off
LED off
CPU is in STOP mode.
LED yellow
LED flashes
red
LED flashes
yellow
The user program causes an error.
CPU is in FAULTED status.
LED flashes
yellow
LED off LED off
CPU is performing internal activi-
ties during STOP, e.g. ramp-up
after STOP.
Loading the user program.
LED flashes
yellow
LED off LED off
CPU is in HOLD state.
A programmed breakpoint in the
user program has been reached.