RB500 Power options (Jumpers settings)
Spanish version of this article: 
RouterBOARD 500 series support a wide range of input voltage. JP3 and JP4 jumpers intended to choose input voltage:
1-2 positions for 25..56V DC; 2-3 positions for 6..22V DC
RouterBOARD 500 series are compliant with IEEE802.3af Power over Ethernet standard. JP5 and JP6 jumpers choose to accept power from PoE Ethernet port (Ether1) or from power jack:
1-2 positions for power jack; 2-3 positions for PoE.