Patent ID: 7230412
Filing Date: 2007-06-12
Classification: H04L

Abstract:
1. A system for providing power to a powered device (PD) in a Power over Ethernet (PoE) system, comprising: a PD probing circuit for determining first and second response signals produced in response to respective first and second detection signals supplied over an Ethernet link to a device being probed, and a control circuit, configured for: controlling the PD probing circuit to supply over the Ethernet link the second detection signal greater than the first detection signal if the first response signal does not exceed a threshold value, and determining that a short circuit condition is detected if a detection value defined by a difference between the second response signal and the first response signal is in a first predetermined range, and determining that a Network Interface Card connected to the Ethernet link is detected if the detection value is in a second predetermined range outside of the first predetermined range.