Power supply subsystem for powering a node over communication cabling

摘要

A power supply subsystem configured for connection between a LAN switch and at least one node, the power supply subsystem providing electrical power to the at least node over communication cabling, the power supply subsystem comprising: a management and control unit; at least one port for connection to a LAN switch; a combiner combining power into the communication cabling substantially without interfering with data communication between the LAN switch and the at least one node; and current limiting circuitry controlling current of the power delivered into the communication cabling via the combiner, wherein the management and control unit is operative to interrogate the at least one node to which it is intended to transmit power over the communication cabling in order to determine whether the node's characteristics allow it to receive power over the communication cabling.