INLINE POWER CONTROL

• US 20100042854A1
• Filed: 10/29/2009
• Published: 02/18/2010
• Est. Priority Date: 07/11/2003
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Provost, Jeffrey D.
• Granted Patent: US 8,543,844 B2
• Time in Patent Office: Days
• US Class Current: 713/300
• CPC Class Codes: G06F 1/266 Arrangements to supply power to external peripherals either directly from the computer or under computer control, e.g. supply of power through the communication port, computer controlled power-strips
• CPC Class Codes: H04L 12/10 Current supply arrangements

Abstract

A physical layer for an inline power device of a network power system. The network power system includes inline power devices such as power source equipment and a plurality of powered devices and further includes a plurality of corresponding transmission media. The plurality of transmission media are connected to the corresponding power source equipment and powered devices through a power interface at each end of the transmission media. The multiple power interfaces of the power source equipment are often referred to as ports. For each port of the power source equipment and the plurality of powered devices, there exists a physical layer. The physical layer includes an inline power control signal source. The inline power control signal designates when to apply power to a port when there is no power applied to the port and when to remove power from the port when there is power applied to the port.

Claims

1. A physical layer (PHY) for an inline power device of a network power system, the PHY comprising:

PHY sublayer circuitry constructed and arranged to exchange data communications signals with an external device through a port of the inline power device; and

an inline power control signal source coupled to the PHY sublayer circuitry and constructed and arranged to output an inline power control signal, the inline power control signal being configured to control inline power, including (i) to supply power to the external device through the port when the external device is coupled to the port and (ii) to remove power from the port when the external device is decoupled from the port.

2. The PHY as recited in claim 1, further comprising an output terminal of the PHY, coupled to the inline power control signal source, the output terminal being constructed and arranged to output the inline power control signal from the inline power control signal source to a power supply of the inline power device, wherein the power supply is configured to deliver power to the external device through the port.

3. The PHY as recited in claim 1, wherein the inline power control signal source is constructed and arranged to output a plurality of inline power control signals.

4. The PHY as recited in claim 3, wherein each of the plurality of inline power control signals is configured for controlling power applied to a different external device through a different port of the inline power device.

5. The PHY as recited in claim 1, wherein the inline power control signal is provided in the form or a plurality of electrical signals and the inline power control signal source has a plurality of output contacts to provide the plurality of electrical signals of the inline power control signal.

6. The PHY as recited in claim 1, wherein the PHY sublayer circuitry comprises at least one of a physical coding sublayer (PCS) and a physical medium attachment (PMA).

7. The PHY as recited in claim 1, further comprising an input and/or output for connecting to a media independent interface (MII) or a gigabit media independent interface (GMII).

8. An apparatus for connecting to a network power system, the apparatus comprising:

a port constructed and arranged to couple said apparatus to a network device and to pass data and power therebetween; and

a physical layer (PHY) coupled to said port, the PHY constructed and arranged to exchange data signals with said network device via said port, the PHY including an inline power control signal source to control power applied to said port for powering said network device.

9. The apparatus as recited in claim 8, wherein the inline power control signal source is constructed and arranged to output an inline power control signal, the inline power control signal being configured indicate when to apply power to a port when there is no power applied to the port and when to remove power from the port when there is power applied to the port.

10. The apparatus as recited in claim 9, wherein the PHY comprises a single pin to output the inline power control signal.

11. The apparatus as recited in claim 8, wherein the inline power control signal source is constructed and arranged to generate a plurality of inline power control signals.

12. The apparatus as recited in claim 8, wherein the apparatus comprises power source equipment and wherein the port is one of a plurality of ports for constructed and arranged to couple the power source equipment to a plurality of network devices.

13. The apparatus as recited in claim 12, wherein the inline power control signal source is constructed and arranged to output a different inline power control signal for each of the plurality of ports.

14. The apparatus as recited in claim 13, wherein each of the different inline power control signals controls power applied to its respective port.

15. The apparatus as recited in claim 8, wherein the apparatus comprises a powered device.

16. The apparatus as recited in claim 8, wherein the apparatus comprises a network switch.

17. A method of controlling inline power in a network power system, the method comprising:

providing a first network device having a port and a physical layer (PHY) coupled to the port;

sourcing an inline power control signal from the PHY;

applying power to a second network device coupled to the port in response to the inline power control signal sourced from the PHY;

outputting data signals from the PHY; and

transmitting the data signals through the port to the second network device.

18. The method as recited in claim 17, further comprising removing power from the second network device in response to the inline power control signal sourced from the PHY.

19. The method as recited in claim 17, wherein:

the first network device has a plurality of ports coupled to a plurality of network devices,

the sourcing step comprises sourcing a plurality of inline power control signals from the PHY, and

the applying step comprises applying power to the plurality of network devices through the plurality of ports in response to the plurality of inline power control signals.

20. The method as recited in claim 19, wherein the step of applying power further comprises each of the plurality of inline power control signals controlling power applied to a different one of the plurality of network devices.