Digi support page: http://www.digi.com/support/productdetail?pid=3510&type=documentation links to hardware reference manual: http://ftp1.digi.com/support/documentation/90001247_C.pdf
Page 9 module connector pin#1 = VETH+, pin#2 = VETH-
Page 58/59 has a sample schematics for PoE support.
Page 20 lists -48V DC input on P13, and 12V DC output on P14
See also development board schematics: http://ftp1.digi.com/support/documentation/30006001-06revA.pdf page 3.
VETH+ is directly connected to pin 4+5 of the RJ45 Ethernetmagnetics, VETH- directly to pin 7+8. There is no on module rectifier, signals are just passed through from RJ45 to module pins.