DETECTION FOR HIGH POWERED DEVICES

• US 20060171399A1
• Filed: 03/27/2006
• Published: 08/03/2006
• Est. Priority Date: 10/16/2003
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Microsemi Corp. - Analog Mixed Signal Group, Ltd. (Microchip Technology Incorporated)
• Inventors: Blaut, Roni, FERENTZ, Alon
• Granted Patent: US 7,593,756 B2
• Time in Patent Office: Days
• US Class Current: 370/395.530
• CPC Class Codes: H04L 12/10 Current supply arrangements

Abstract

A powering source unit comprising: a first powering source; a second powering source; the first powering source being operable to: apply a plurality of voltages towards a powered device via a first path so as to detect a signature impedance, and in the event the signature impedance is detected, to at least partially classify the power requirements of the powered device by supplying a classification voltage towards the powered device via the first path and measuring the resultant current flow, the classification voltage level being higher than each of the plurality of detection voltage levels; the second powering source being operable to apply at least one voltage towards the powered device via a second path so as to attempt to detect a signature impedance at least partially contemporaneously with the supplied classification voltage of the first powering source.

Claims

1. A local area network adapted to supply power to a plurality of types of powered devices over communication cabling, the local area network comprising:

a powered device comprising at least one signature impedance;

a first powering source;

a second powering source; and

communication cabling comprising a plurality of twisted wire pairs arranged to connect said first and second powering source to said powered device, said communication cabling providing a first power path comprising a first set of twisted wire pairs of said communication cabling between said first powering source and said powered device and a second power path comprising a second set of twisted wire pairs of said communication cabling between said second powering source and said powered device, said first set being different from said second set,

said first powering source being operable to;

apply a plurality of voltages to said powered device via said first path so as to attempt to detect a first one of said at least one signature impedance, and in the event said first one of said at least one signature impedance is detected, to

at least partially classify the power requirements of said powered device by supplying a classification voltage to said powered device via said first path and measuring the resultant current flow, said classification voltage level being higher than each of the plurality of detection voltage levels;

said second powering source being operable to apply at least one voltage to said powered device via said second path so as to attempt to detect a second one of said at least one signature impedance at least partially contemporaneously with said supplied classification voltage of said first powering source.

2. A local area network according to claim 1, further comprising a power sourcing controller, said first and second powering source being responsive to said power sourcing controller.

3. A local area network according to claim 1, wherein said powered device comprises one of:

a first type of powered device arranged to accept power over either one of said first power path and said second power path, said first type of powered device exhibiting a single signature impedance to said first and second paths; and

a second type of powered device arranged to accept power over both said first power path and said second power path, said second type of powered device adapted to exhibit said signature impedance to said second path while receiving said classification voltage on said first path.

4. A local area network according to claim 3, wherein in the event said powered device is of said first type, said second powering source will not detect said single signature impedance.

5. A local area network according to claim 1, wherein in the event said first powering source detects said first one of said at least one signature impedance and said second powering source detects said second one of said at least one signature impedance, said first and second powering sources are further operable to power said powered device via both said respective first and second paths.

6. A local area network according to claim 1, further comprising a power sourcing controller in communication with said first powering source and said second powering source, and wherein in the event said first powering source detects said first one of said at least one signature impedance and said second powering source detects said second one of said at least one signature impedance, said first and second powering sources are further operable by said power sourcing controller to power said powered device via both said respective first and second paths.

7. A local area network according to claim 1, wherein in the event said first powering source detects said first one of said at least one signature impedance and said second powering source detects said second one of said at least one signature impedance, said second powering source is further operable to at least partially classify the power requirements of said powered device by supplying a supplying a classification voltage to said powered device via said second path and measuring the resultant current flow.

8. A local area network according to claim 7, wherein said first and second powering sources are operable to power said powered device via said respective first and second paths responsive to said at least partial classifications.

9. A local area network according to claim 7, further comprising a power sourcing controller in communication with said first powering source and said second powering source, said power sourcing controller being operable to classify said the power requirements of said powered device responsive to said measured resultant current flow of said classification voltage of said first powering source and said measured resultant current flow of said classification voltage of said second powering source.

10. A local area network according to claim 1, wherein in the event said first powering source does not detect said first one of said at least one signature impedance, said second powering source is operable to apply a plurality of voltages to said powered device via said second path so as to attempt to detect said at least one signature impedance.

11. A local area network according to claim 10, wherein in the event said second powering source detects said at least one signature impedance, said second powering source is further operable to power said powered device via said second path.

12. A local area network according to claim 10, further comprising a power sourcing controller in communication with each of said first powering source and said second powering source, and wherein in the event said second powering source detects said at least one signature impedance, said second powering source is further operable responsive to said power sourcing controller to:

at least partially classify the power requirements of said powered device by supplying a classification voltage to said powered device via said second path and measuring the resultant current flow; and

power said powered device via said second path responsive to said at least partial classification.

13. A local area network according to claim 10, wherein in the event said second powering source detects said at least one signature impedance, said second powering source is further operable to:

at least partially classify the power requirements of said powered device by supplying a classification voltage to said powered device via said second path and measuring the resultant current flow; and

power said powered device via said second path responsive to said at least partial classification.

14. A local area network according to claim 1, wherein in the event said first powering source detects said first one of said at least one signature impedance and said second powering source does not detect said second one of said at least one signature impedance, said first powering source is operable to power said powered device via said first power path responsive to said at least partial classification.

15. A method of detecting, classifying and powering a powered device, the method comprising:

providing a first powering source;

providing a second powering source;

attempting to detect via applying a plurality of voltages from said provided first powering source a first signature impedance of a connected powered device;

in the event said signature impedance is detected by said provided first powering source,

at least partially classifying the power requirements of the powered device by providing a classification voltage from said provided first powering source to the connected powered device, said classification voltage being greater than any of said applied plurality of voltages of said detecting; and

attempting to detect via applying at least one voltage from said provided second powering source a second signature impedance of a connected powered device at least partially contemporaneously with said at least partially classifying of said provided first powering source,

said provided classification voltage preventing said detection of the second signature impedance in the event said first powering source and said second powering source are connected to a powered device arranged to accept power from either one, but not both, of said first and second powering source.

16. A method according to claim 15, further comprising in the event said first powering source detects said first signature impedance and said second powering source detects said second signature impedance at least partially contemporaneously with said at least partially classifying of said provided first power source:

powering the powered device via both said provided first and second powering source.

17. A method according to claim 15, further comprising in the event said first powering source detects said first signature impedance and said second powering source detects said second signature impedance:

at least partially classifying the power requirements of the powered device equipment by providing a classification voltage from said provided second powering source; and

powering the powered device via both said provided first and second powering source responsive to said at least partial classifications.

18. A method according to claim 15, further comprising in the event said provided first powering source does not detect a signature impedance:

attempting to detect via applying a plurality of voltages from said provided second powering source a signature impedance of the connected powered device.

19. A method according to claim 18, further comprising in the event said provided second powering source detects said signature impedance:

powering the powered device via said provided second powering source.

20. A method according to claim 18, further comprising in the event said provided second powering source detects said signature impedance:

at least partially classifying, by providing a classification voltage from said provided second powering source, the power requirements of the powered device; and

powering the powered device from said provided second powering source responsive to said at least partial classification.

21. A method according to claim 15, further comprising in the event said provided first powering source detects said first signature impedance and said provided second powering source does not detect said second signature impedance:

powering the powered device from said provided first powering source responsive to said at least partial classification.

22. A method according to claim 15, wherein said provided classification voltage not preventing said detection of the second signature impedance in the event said first powering source and said second powering source are connected to a powered device arranged to accept power from both of said first and second powering sources.

23. A powering source unit adapted to supply power to a plurality of types of powered devices over communication cabling, the powering source unit comprising:

a first powering source; and

a second powering source;

said first powering source being operable to;

apply a plurality of voltages towards a powered device via a first path so as to attempt to detect a signature impedance, and in the event said signature impedance is detected, to

at least partially classify the power requirements of the powered device by supplying a classification voltage towards said powered device via the first path and measuring the resultant current flow, said classification voltage level being higher than each of the plurality of detection voltage levels;

said second powering source being operable to apply at least one voltage towards the powered device via a second path so as to attempt to detect a signature impedance at least partially contemporaneously with said supplied classification voltage of said first powering source.

24. A powering source unit according to claim 23, wherein in the event said first powering source detects the signature impedance and said second powering source detects the signature impedance, said first and second powering sources are further operable to supply power towards the powered device.

25. A powering source unit according to claim 23, further comprising a power sourcing controller in communication with each of said first powering source and said second powering source, said attempting to detect and said classifying being responsive to said power sourcing controller.