Description of the device 
  2.4 LED display 
SCALANCE M874, M876 
Operating Instructions, 08/2018, C79000-G8976-C331-08 
23 
 
F  OFF 
No fault/error. 
ON 
 
The device is starting up or an error has occurred. 
Possible errors/faults:  
•  Wrong PIN number 
Flashing 
The bootloader waits in this state for a new firmware file that you can 
download using TFTP. 
Flashing 
 
at the interval: 
2000 ms on / 
Firmware on PLUG  
The device is performing a firmware update or downgrade.