Systems and Methods for Detecting Powered or Powering Device Configuration Via Ethernet Connection

A method for detecting a PoE (power over Ethernet) device, the method comprising:

• applying a positive polarity of a first current source to one of a first and second data pairs of an Ethernet cable connection to a powered device (PD) and a negative polarity of the first current source to the other of the first and second data pairs;
• applying a positive polarity of a second current source to a second spare pair of the Ethernet cable connection and a negative polarity of the first current source to a first spare pair of the Ethernet connection;
• simultaneously measuring a first voltage across the first current source and a second voltage across the second current source;
• discontinuing application of the first current source and measuring a third voltage across the second current source;
• and
• determining a configuration of the PD using the measured first, second and third voltages.

A method for detecting a configuration of a power supply equipment device (PSE) connected to a powered device (PD), the method comprising:

• simultaneously measuring a first voltage at a first terminal of a resistor and a second voltage at a second terminal of the resistor, the resistor disposed within the PD;
• and
• determining the configuration of the PSE using the measured first and second voltages;
• wherein the PD further comprises first and second full-wave rectifiers, the first terminal of the resistor connected to a rectified positive rail of the first and second full-wave rectifiers and the second terminal of the resistor connected to a terminal corresponding to pins 4 and 5 of a spare pair Ethernet cable connection of the PD.