Patent ID: 6581163
Filing Date: 2003-06-17
Classification: H04M,H04Q

Abstract:
An apparatus for the sending and detection of the loss of AC mains power comprising:a power supply including: a mains AC to DC converter having a first output voltage and a plurality of second output voltages, each of said second output voltages having an operational value while said mains AC is present and a signaling value when said mains AC is not present, whereby after the removal of said mains AC, one or more of said second outputs is at said signaling value and said first output is maintained for a holdup time thereafter; a network device including: a primary communications interface powered by said first output voltage; one or more secondary communications interfaces powered by one or more of said second output voltages; a CPU powered by said first output voltage and coupled to said primary communications interface and forming messages which are sent over said primary communications interface, said CPU having a power fail input and sending a power fail message over said primary communications interface when said power fail signal input is asserted; said power fail signal input asserted when one or more of said secondary output voltages is at said signaling level; where said power supply and said network device are interconnected only by said first voltage and said second voltages.