The TP-DCDC-1224-HP DC to DC converters offered by Tycon Power Systems are a 
low cost and high reliability solution for those requiring 24VDC Power Over 
Ethernet voltage from a +/-12V battery system. 
They have an integrated 10/100Mb Passive PoE injector to apply the regulated 
24VDC to the CAT5 Ethernet cable. The input voltage must be between 10VDC and 
15VDC. 
They accept data-in to a shielded RJ45 Jack and provide data-out and PoE 
power on the shielded RJ45 output jack. They work by supplying power on the 
unused Ethernet pins 4,5(V+) and 7,8(V-). 
They have various protections for surge, short circuit and overload. The 
units have power output of 30W.