Pre-detection of powered devices
First Claim
1. A method for preventing harmful transients resulting from a probing routine for a valid powered device detection signature in a network, the method comprising:
- providing a pre-detection voltage to the output port of a power sourcing equipment via an impedance, said provided pre-detection voltage restricted so that voltage at the output port in the absence of a load across the output port is less than a predetermined threshold at which damaging transients can occur, said predetermined threshold less than or equal to 5 volts;
obtaining an indication of voltage at the output port of the power sourcing equipment responsive to said provided pre-detection voltage;
comparing said obtained indication of voltage at the output port of the power sourcing equipment responsive to said provided pre-detection voltage with a pre-determined value; and
initiating, only in the event that said obtained indication of voltage at the output port of the power sourcing equipment responsive to said provided pre-detection voltage is less than said pre-determined value, a probing routine for a valid powered device detection signature.
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Accused Products
Abstract
A method and apparatus for preventing harmful transients resulting from a probing routine for a valid powered device detection signature in a network, the method comprising: operating power sourcing equipment to provide via its output port a pre-detection output voltage; obtaining an indication of the pre-detection output voltage; comparing the indication of the pre-detection output voltage with a pre-determined value; and in the event that the indication of the pre-detection output voltage is less than the pre-determined value; initiating a probing routine for a valid powered device detection signature. The higher voltage of the probing routine is thus not present at the output port in the absence of pre-detection of a potentially valid powered device detection signature.
21 Citations
28 Claims
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1. A method for preventing harmful transients resulting from a probing routine for a valid powered device detection signature in a network, the method comprising:
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providing a pre-detection voltage to the output port of a power sourcing equipment via an impedance, said provided pre-detection voltage restricted so that voltage at the output port in the absence of a load across the output port is less than a predetermined threshold at which damaging transients can occur, said predetermined threshold less than or equal to 5 volts; obtaining an indication of voltage at the output port of the power sourcing equipment responsive to said provided pre-detection voltage; comparing said obtained indication of voltage at the output port of the power sourcing equipment responsive to said provided pre-detection voltage with a pre-determined value; and initiating, only in the event that said obtained indication of voltage at the output port of the power sourcing equipment responsive to said provided pre-detection voltage is less than said pre-determined value, a probing routine for a valid powered device detection signature. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. Power sourcing equipment for detecting and powering a valid powered device in an Ethernet network, the power sourcing equipment comprising:
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one of a voltage source and a current source; an impedance; an output port; and a control circuitry, said one of a voltage source and a current source arranged to be connected via said impedance to said output port responsive to said control circuitry; said control circuitry arranged to; provide from said one of a voltage source and a current source via said impedance a pre-detection voltage, said pre-detection voltage restricted so that voltage at the output port in the absence of a load across the output port is less than a predetermined threshold at which damaging transients can occur, said predetermined threshold less than or equal to 5 volts; obtain an indication of voltage at said output port responsive to said pre-detection voltage; compare said obtained indication of voltage at said output port responsive to said pre-detection voltage with a pre-determined value; and initiate, only in the event that said obtained indication of voltage at said output port responsive to said pre-detection voltage is less than said pre-determined value, a probing routine for a valid powered device detection signature. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A method for preventing harmful transients while enabling detection of a valid powered device detection signature in a network, the method comprising:
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operating power sourcing equipment to provide via its output port a first voltage, said provided first voltage less than a predetermined threshold at which damaging transients can occur, said predetermined threshold less than or equal to 5 volts; obtaining an indication of voltage at the output port of the power sourcing equipment responsive to said provided first voltage; comparing said obtained indication of voltage at the output port of the power sourcing equipment responsive to said provided first voltage with a pre-determined value; and operating, only in the event that said obtained indication of voltage at the output port of the power sourcing equipment responsive to said provided first voltage is less than said pre-determined value, said power sourcing equipment to provide via its output port a second voltage thereby probing for a valid powered device detection signature.
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23. A method for detecting a valid powered device detection signature in a network, the method comprising:
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operating power sourcing equipment to provide via its output port a first voltage, said provided first voltage less than a predetermined threshold at which damaging transients can occur, said predetermined threshold less than or equal to 5 volts; measuring said first voltage at said output port; comparing said measured first voltage with a pre-determined value; and operating, only in the event that said measured first voltage is less than said pre-determined value, said power sourcing equipment to provide via its output port at least two additional voltages; measuring said at least two additional voltages at said output port; and determining a valid powered device detection signature utilizing said measured first voltage and said measured two additional voltages. - View Dependent Claims (24)
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25. A method for preventing harmful transients while enabling detection of a valid powered device detection signature in a network, the method comprising:
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operating power sourcing equipment to provide via its output port two first voltages, each of said two first voltages less than a predetermined threshold at which damaging transients can occur, said predetermined threshold less than or equal to 5 volts; obtaining an indication of each of said two first voltages at the output port; determining a difference between said obtained indication of said two first voltages at the output port; comparing said determined difference with a pre-determined value; and operating, only in the event that said determined difference is less than said pre-determined value, said power sourcing equipment to provide via its output port a second voltage thereby probing for a valid powered device detection signature. - View Dependent Claims (26, 27)
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28. A system for detecting and powering a valid powered device in an Ethernet network comprising:
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a powered device; and power sourcing equipment coupled by communication cabling to said powered device, said power sourcing equipment being arranged to; provide via its output port a pre-detection voltage, said provided pre-detection voltage less than 5 volts; obtain an indication of said pre-detection voltage at said output port; compare said obtained indication of said pre-detection voltage at said output port with a pre-determined value; and initiate, only in the event that said obtained indication is less than said pre-determined value, a probing routine for a valid powered device detection signature.
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Specification