Supply voltage
EtherCAT P Box modules indicate the status of the supply voltages via two status LEDs. The status LEDs are labeled with the designations of the supply voltages: Us and Up.
LED  | Display  | Meaning  | 
|---|---|---|
US (control voltage)  | off  | US not present.  | 
green illuminated  | US present.  | |
red illuminated  | Error. 1)  | |
UP (peripheral voltage)  | off  | UP not present.  | 
green illuminated  | UP present.  | |
red illuminated  | Error. 1)  | 
1) Overload of the sensor supply/auxiliary voltage output at the signal interfaces.
You can find out whether the sensor supply/auxiliary voltage is derived from US or from UP from the assignment of the signal interfaces.