Patent ID: 7593756

Claim:
A local area network adapted to supply power to a plurality of types of powered devices over communication cabling, the local area network comprising: a powered device comprising at least one signature impedance; a first powering source exhibiting a power output and a return; a second powering source exhibiting a power output and a return, said second powering source different from said first powering source; and communication cabling comprising a plurality of twisted wire pairs arranged to connect said first and second powering source to said powered device, said communication cabling providing a first power path coupling said power output and said return of said first powering source to said powered device, said first power path comprising a first set of twisted wire pairs of said communication cabling and a second power path coupling said power output and said return of said second powering source to said powered device, said second power path comprising a second set of twisted wire pairs of said communication cabling between said second powering source and said powered device, said first set being different from said second set, said first powering source operative to: apply a plurality of detection voltages to said powered device via said first path so as to attempt to detect a first one of said at least one signature impedance, and in the event said first one of said at least one signature impedance is detected, to at least partially classify the power requirements of said powered device by supplying a classification voltage to said powered device via said first path and measuring the resultant current flow, said classification voltage level being higher than each of the plurality of detection voltages; said second powering source operative to apply a detection voltage to said powered device via said second path so as to attempt to detect a second one of said at least one signature impedance at least partially contemporaneously with said supplied classification voltage of said first powering source.