Siemens S7-1500 Operating Instructions Manual page 23

The following table shows the meaning of the various combinations of colors of the RUN,
ERROR and MAINT LEDs.
Table 2- 3
LED lit green
LED lit green
LED lit green
LED lit green
LED lit green
LED lit green
LED flashing
LED flashing
CP 1543-1
Operating Instructions, 05/2017, C79000-G8976-C289-07
Meaning of the LEDs "RUN", "ERROR", "MAINT"
RUN ERROR
LED off LED off
LED lit red
LED lit red
LED off
LED flashing red
LED off
LED off
LED off
green
LED flashing red
green
MAINT
No supply voltage on the CP or supply
voltage too low.
LED off
LED test during startup
LED lit yellow
Startup (booting the CP)
LED off
CP is in RUN mode.
LED off
No disruptions
A diagnostics event has occurred.
LED off
Maintenance, maintenance is demand-
ed.
LED lit yellow
Maintenance is required.
Downloading the user program
LED flashing
yellow
No CP configuration exists
LED off Loading firmware
Module fault
(LEDs flashing synchronized)
LED flashing
yellow
Product overview, functions
2.7 LEDs
Meaning
23