Description of the device   
4.7 LED display 
  SCALANCE XM-400 
36  Operating Instructions, 09/2018, C79000-G8976-C306-08 
 
The port LEDs "P1", "P2" etc. show information about the corresponding ports. 
The meaning of the Port LEDs depends on the set display mode, see section "LEDs "DM1" 
and "DM2" (Page 34)". 
Meaning in display mode A 
In display mode A, the port LEDs indicate whether a valid link exists. 
 
-  Off  No valid link to the port (for example communications 
partner turned off or cable not connected). 
Green  On  Link exists and port in normal status. In this status, the 
port can receive and send data. 
Flashes once per period*  Link exists and port in "Blocking" status. In this status, the 
port only receives management data (no user data). 
Flashes three times per 
Link exists and port turned off by management. In this 
status, no data is sent or received via the port. 
Flashes four times per 
Link exists and is in the "Monitor Port" status. In this sta-
tus, the data traffic of another port is mirrored to this port. 
* 1 period ≙ 2.5 seconds 
Meaning in display mode B 
In display mode B, the port LEDs indicate the transmission speed. 
 
Port operating at 10 Mbps 
Port operating at 100 Mbps 
Port operating at 1000 Mbps 
Port operating at 10 Gbps 
If there is a connection problem and the type of transmission is fixed (auto negotiation off), 
the desired status, in other words the set transmission speed (1000 Mbps, 100 Mbps, 10 
Mbps) continues to be displayed. If there is a connection problem and auto negotiation is 
active, the port LED goes off. 
Meaning in display mode C 
In display mode C, the port LEDs indicate the mode. 
 
Port operating in half duplex mode 
Port operating in full duplex mode