Siemens SIMATIC ET 200SP Operating Instructions Manual page 59

RUN/STOP LED
yellow/green
LED flashes green
POWER LED
Table 9-2
CPU 1515SP PC2 (F/T/TF)
Operating Instructions, 03/2023, A5E42603425-AC
ERROR LED
LED flashes red
LED flashes
LED flashes red
POWER LED
POWER LED
LED off
LED lights up yellow
LED green
Interrupt, error and system messages
MAINT LED
Startup (CPU booting)
Test of LEDs during startup, inserting a
LED flashes yellow
module.
LED flashing test
CPU defective
LED flashes red
Meaning
No supply voltage or supply voltage too low;
operating system is shut down
Supply voltage present;
running through BIOS phase
Supply voltage present;
Booting or operation of the operating system
9.1 Status and error display
Meaning
57