thereof to a power supply 540 the power line network access circuitry 538 which may be part of a peripheral component interconnect pci card provides digital data through the digital interface 542 and receives digital data from the digital interface 542 the pci card may be for example a network interface card nic 550 note that the present invention does not require a separate network interface card nic power line network access circuitry generally refers to circuitry for transmission or reception of data over a power line or circuitry for processing such data to or from a host controller the digital interface 542 generally includes a transmitter to transmit digital data to the power supply 540 and a receiver to receive digital data from the power supply 540 in addition to data signals the digital data may include control signals such as afe adc and dac control signals and clock synchronization signals the power supply 540 is adapted for digital data coupling to the nic 550 a digital coupler 536 generally defines a bidirectional communication interface between the nic 550 and the power supply 540 the digital coupler 536 represents a digital communication channel between the nic 550 and the power supply 540 on the nic or pci.