TWI448882B - Reduced guard band for power over ethernet - Google Patents

Description

Reduce the protection band of the Ethernet power supply

The present invention relates to the field of Ethernet power supply, and more particularly to an Ethernet power supply system that exhibits a dynamic guard band that prevents power to be supplied to additional ports.

The growth of regional networks and wide area networks based on Ethernet technology has become an important driving force for cabling between offices and homes through a structured cabling system with multiple ridge pairs. The ubiquitous regional network and the equipment operating on the local area network have led to the often need to attach a network-operated device that is advantageously used by the network on the network cabling. powered by. Powering over network cabling has several advantages, including (but not limited to): reduced installation costs; centralized power and power backup; and centralized security and management.

There are a number of patents in the U.S. Patent No. 6,473,608 issued to Lehr et al. This is incorporated herein by reference. In addition, standards for embarking on the issue of powering remote devices over Ethernet-based networks have been published as IEEE 802.3af-2003, the contents of which are incorporated herein by reference, and hereinafter referred to as the "af" standard. A device that receives power on a network cabling is referred to as a powered device (PD), and powering equipment that transfers power to the network cabling for use by the PD is referred to as power sourcing equipment. PSE).

Commercially available PSEs are supplied to support a single 埠 or to support multiple 埠. For the sake of clarity, each of the plurality of power over Ethernet (PoE) controllers serving a plurality of devices is referred to as a PSE and exhibits the electrical characteristics described in the "af" standard.

A plurality of service PoE controllers are preferably provided with power management functionality that prevents power to be supplied to all of the powers of the power drawn when the total power consumption of the power is within a predetermined range of available total power. In an exemplary embodiment, this is achieved by providing a guard band, as disclosed in US 2005/0049758 A1, entitled "METHOD AND APPARATUS FOR POWER MANAGEMENT IN A LOCAL AREA NETWORK", filed on September 27, 2004. The same is described in U.S. Patent Application Serial No. S/N. In an exemplary embodiment, the guard band is equal to or greater than the maximum power that can be taken by a PD or PD, regardless of the effect of the inrush current. Therefore, by constructing a guard band, it is not possible to supply power to a PD that will make the total used power exceed the total available power. It will be appreciated that where the total used power exceeds the total available power, the power supply will be overloaded and turned off unless at least one power supply is lost.

The power management function is further operated to monitor the total power consumption of the system. In the event that the power consumption is within the guard band limits of the total available power, no additional PD is powered. In the event that the power consumption meets or exceeds the total available power, or otherwise reaches or exceeds the limit below the total available power, the PD is disabled to reduce the total power consumption. Preferably, the PD is disabled while maintaining priority, whereby the low priority PD is first disabled and the higher priority PD is powered.

Each PD is connected to a unique port of a particular Ethernet power controller, and therefore, disabling the pin is synonymous with disabling the PD.

The above mechanism is generally satisfactory, but in the case of using a small power supply (which has a capacity of about 2 to 4 fully powered "af" ports), the guard band prevents the use of a significant portion of the power supply capacity. This is especially problematic in the case where the attached PD draws power far below the maximum allowed by the "af" standard, and thus can supply a large number of PDs in the absence of the guard bands mentioned above.

What is required and not provided by prior art is a method of dynamically providing a guard band that enables the maximum number of PDs to be powered without exceeding the capacity of the power source.

Accordingly, one primary object of the present invention is to overcome the shortcomings of the prior art. In the present invention, there is provided a method for dynamically allocating a guard band in response to a PD that is powered and then disabled by power management functionality, the power management functionality indicating after powering the PD The total power drawn is greater than the maximum available power. In one specific example, the guard band is set for all ports of the system, and in another example, the guard band is set for the disabled.

In a specific example of setting a guard band on a system-wide basis, the guard band is cleared by one of: the total power consumption is less than the total available power minus the guard band; and a PD is connected to a higher than the power source. Management of the priority of the functional disability; and a predetermined period of time has expired.

In a specific example of setting a guard band for the disabled, the guard band is cleared by one of the following: a detection period in which no connection to the 相关 associated with the disabled PD is detected. PD; and a predetermined time period has expired; and the total power consumption is less than the total available power minus the guard band.

In one embodiment, the present invention provides a method of controlling an Ethernet power supply system, the method comprising: sequentially supplying a plurality of powered devices on a communication cable; and responding to powering the plurality of powered devices Determining a first total power consumption; and disabling the power of at least one of the plurality of powered devices that are powered, if the determined first total power consumption exceeds a predetermined maximum power level, Reducing the power consumption to be lower than the predetermined maximum power level; determining a connection power limit that is less than the maximum power level to a guard band in response to the disabling power; monitoring the first after the disabling power Two total power consumption; and enabling power to a powered device only if the monitored second total power consumption is less than the connected power limit.

Additional features and advantages of the invention will be apparent from the description and drawings.

For a better understanding of the invention, the invention may be understood by reference to the accompanying drawings.

The detailed description is to be considered as illustrative of the preferred embodiments of the invention The most useful and easy to understand description of the situation. In this regard, the details of the structure of the present invention are not intended to be construed as a Many forms.

This embodiment enables a method of dynamically allocating a guard band in response to a PD that is powered and then disabled by power management functionality, the power management functionality indicating the total power drawn after powering the PD Greater than the maximum available power. In one specific example, the guard band is set for all ports of the system, and in another example, the guard band is set for the disabled.

In a specific example of setting a guard band on a system basis, the guard band is cleared by one of the following: the total power consumption is less than the total available power minus the guard band; a PD is connected to one with a higher power management function The priority of sexual disability; and a predetermined period of time has expired.

In a specific example of setting a guard band for the disabled, the guard band is cleared by one of the following: a detection period in which no connection to the 相关 associated with the disabled PD is detected. PD; and a predetermined time period has expired; and the total power consumption is less than the total available power minus the guard band.

Before explaining at least one specific embodiment of the present invention, it is understood that the application of the present invention is not limited to the details of the construction and configuration of the components described in the following description or illustrated in the drawings. The invention is applicable to other specific examples or to practice or practice in various ways. It will be understood that the phraseology and terminology used herein is for the purpose of description

1 is a high level schematic diagram of an Ethernet power supply system including an Ethernet power manager 10 that provides power to each of a plurality of powered devices 20 on a respective communication cable 30. Further, a host 40 and a power source 50 are included. The Ethernet power management unit 10 includes a control circuit 60, a detection function 70 associated with the control circuit 60, and a plurality of electrical control switches 80 associated with a particular port 85, illustrated as sensing resistors. A plurality of current sensors 90 and a voltage sensor 100. The control inputs of each of the electrical control switches 80 are coupled to respective outputs of the control circuit 60, and the sense outputs of each of the current sensors 90 are coupled to respective inputs of the control circuit 60. In each of the specific examples in which the current sensor 90 is represented by a sense resistor, each end of the sense resistor 90 is connected to a respective input control circuit 60.

The output of power supply 50 is connected in parallel to the input of each electrical control switch 80 via a respective current sensor 90. The output of each electrical control switch 80 is coupled to a particular PD 20 via a respective port 85 and a respective communication cable 30. The PD 20 is not required to be connected to each of the ports 85, and as will be further described below, the detection functionality 70 is operable to detect the presence or absence of a connected PD 20.

Each communication cable 30 can be pluggable or directly connected to a particular Ethernet power management unit 10 at each port 85. The combination of voltage sensor 100 and current sensor 90 represents a power sensor operable to determine connection to all of PD 28 of power or Ethernet manager 10 when combined with current sensor 90 The total power consumption, and the power consumption of each PD 20 drawn from the Ethernet power manager 10 is determined by the respective current sensor 90. Host 40 is in communication with control circuitry 60. In one embodiment, host 40 communicates with control circuitry 60 over a network such as an Ethernet network, and in another embodiment, host 40 is directly coupled to control circuitry 60.

In operation, control circuit 60 is in communication with host 40 and receives information regarding the maximum power output of power source 50. The control circuit 60 further operates the detection functionality 70 to detect the presence of the active PD 20 connected to each of the ports 85 on the communication cable 30 and to close each other in response to the detection of the active PD 20 connected to the port 85. The switch 80 is electrically controlled whereby power is supplied to the PD 20 over the communication cable 30. Control circuit 60 is further operative to monitor the power consumption of all powered PDs 20, and (as further explained below) disables at least one PD 20 in response to a power overload. It will be appreciated that power source 50 is preferably used to power all or the largest number of detected PDs 20 without exceeding their rated maximum capacity.

Because powering the PD 20 results in an overload condition, it is intended that powering up the maximum number of detected PDs 20 while not exceeding the capacity of the power source 50 can result in a situation in which a PD 20 is alternately powered and then disabled. 2A is a depiction of a powered device oscillating between a powered state and a disabled state due to a power overload according to one of the prior art, wherein the x-axis describes time and the y-axis is described from the Ethernet power manager The total power consumption of all PDs 20 that draw power at 10 locations. The maximum power output of power source 50 is labeled P _disconnect because at least one PD 20 is to be disabled or disconnected to prevent overloading of power source 50 if the total power exceeds this amount.

Line 200 represents the steady state power consumption of one or more detected and powered PDs 20 that are less than P _disconnect . Line 210 represents the detection and powering of additional PD 20 that exceeds P _disconnect when fully powered (preferably without considering any instantaneous inrush current) as indicated by point 220. Control circuit 60 then acts to reduce power consumption by disabling at least one PD 20. It will be appreciated that the term "disabling" is synonymous with an open circuit associated with the electrical control switch 80 associated with the power to be removed 85 and the PD 20.

Similar to line 200, line 230 represents steady state power consumption, which is reached after the PD 20 that caused the overload condition of point 220 is disconnected. Control circuit 60 typically polls all ports 85 to detect unpowered PDs 20 connected thereto, and in the event of detection, control circuit 60 operates to detect unpowered PDs as indicated by line 240. 20 is powered, line 240 represents the detection and powering of the additional PD 20, which is greater than P _disconnect when fully powered (preferably without considering any instantaneous inrush current) as indicated by point 250. Control circuit 60 then acts to reduce power consumption by disabling at least one PD 20 as described above.

Therefore, the detection of the functionality 70, the power management caused by the detected PD 20, and the power management functionality to prevent power overload results in oscillations between the PD 20 and the disabled PD 20.

In order to prevent this oscillating, U.S. Patent Application Serial No. S/N 10/949,208, entitled "METHOD AND APPARATUS FOR POWER MANAGEMENT IN A LOCAL AREA NETWORK", which is filed on Sep. 27, 2004, entitled "METHOD AND APPARATUS FOR POWER MANAGEMENT IN A LOCAL AREA NETWORK" As described, prior art teaches the use of guard bands. 2B is a depiction of a guard band that prevents oscillation of FIG. 2A in accordance with the prior art, wherein a limit below P _disconnect is defined, which is labeled P _{no_more_connect} . The guard band is defined as the power range between P _disconnect and P _{no_more_connect} .

In operation, the detected PD 20 is powered as long as the total power consumption does not exceed P _{no_more_connect} . In the case where the total power consumption exceeds P _{no_more_connect} , the additional detected PD 20 is not powered, but no powered PD 20 is disabled. As described above with respect to FIG. 2A, in the event that the total power consumption exceeds _Pdiss , at least one PD 20 is disabled to reduce power consumption below _Pdis . Thus, the use of the guard band of Figure 2B prevents the oscillation of Figure 2A. However, it will be appreciated that for efficiency, the guard band of Figure 2B is preferably large enough to prevent powering up the maximum amount of PD 20 that is drawn, and therefore, the use of the static guard band prevents the capacity of the power source 50. Maximum amount to use.

3 is a high level flow diagram of the operation of the control circuit 60 of FIG. 1 in accordance with the principles of the present invention in which a guard band is dynamically constructed for all chirps in response to a single oscillator event. In stage 1000, the maximum power level of the power source 50 is input. In one embodiment, the maximum power level is communicated from the host 40 to the control circuit 60, and in another embodiment, the maximum power level is communicated directly from the power source 50 to the control circuit 60. The maximum power level is marked as P _disconnect . In addition, the variable labeled P _{connect_limit} is initially set equal to P _disconnect .

In stage 1010, control circuit 60 operates detection functionality 70 to detect PD 20 that is not currently powered. In stage 1020, control circuit 60 operates respective electrical control switches 80 to connect power to PDs 20 detected in stage 1010. In stage 1030, the total power consumption of all powered PDs 20 is determined. In an illustrative embodiment, the total power consumption is determined by inputting the output of each current sensor 90 and the output of voltage sensor 100 and multiplying the sum of the currents by the voltage. The current consumption of the Ethernet power manager 10 (and in particular, the control circuit 60) is preferably subtracted as a constant. In an alternate embodiment, the maximum power level provided by host 40 takes into account the current consumption of Ethernet power manager 10.

The above has been described with respect to a specific example, although the single voltage sensor 100 supplies all of the voltage information of the Ethernet power supply manager 10, this is not meant to be limiting in any way. In an alternative embodiment, the voltage on each of the turns 85 is sensed by a respective voltage sensor (not shown) and input to the control circuit 60. Therefore, the power consumption of each PD 20 is calculated by multiplying the current sensed by the respective current sensors 90 by the voltage sensed by the respective voltage sensors.

In stage 1040, the total power consumption determined in stage 1030 is compared to _Pdiss . Stage 1010 described above is performed with the total power consumption not greater than P _disconnect . In the event that the total power consumption is greater than _Pdiss , in stage 1050, the PD 20 that is to be disabled in response to the overload condition detected in stage 1040 is determined. In one embodiment, the last PD 20 to be powered is determined to be the PD 20 to be disabled according to stage 1020. In another specific example, the lowest priority 目前 currently being powered is determined as the ambiguity of the desire to be disabled. In stage 1060, the power consumption of the PD 20 that is to be disabled according to stage 1050 is determined. In one embodiment, the power consumption of the PD 20 to be disabled is determined in response to the associated current sensor 90, and in another embodiment, based on the reduced total power compared to the power consumption of stage 1030. Consumption, stage 1050 is calculated after the operation of stage 1070 described below. In stage 1070, the power flow of the PD 20 determined in stage 1050 is disabled. In an exemplary embodiment, the power flow is disabled by opening the respective electrical control switch 80.

In stage 1080, the guard band is set to define a connection power limit, the operation of which is similar to that described above with respect to _{Pno_more_connect} of Figure 2B. Preferably, the guard band is a function of the power consumption of the disabled powered device as determined in stage 1060. The variable P _{connect_limit} is set equal to P _disconnect minus the determined guard band. Therefore, the guard band is set by the operation of stage 1080 only if the power consumption has exceeded the initial maximum power level _Pdis . In one embodiment, the guard band is equal to the power consumption of the powered device that is disabled as determined in stage 1060 plus a predetermined value. In yet another embodiment, the predetermined value is sufficient to prevent oscillation between states, and is preferably set to about 2 watts.

In stage 1090, the total power consumption is monitored. In stage 1100, the total power consumption monitored in stage 1090 is compared to the value represented by the variable _{Pconnect_limit} . In the case where the total power consumption monitored is lower than the value indicated by P _{connect_limit} (ie, the total power consumption is lower than the guard band), the variable P _{connect_limit is} reset to the initial value P _disconnect in stage 1110. Thus, where the total power consumption is below the guard band, the guard band is cleared by the action of stage 1110 and stage 1010 described above is performed.

In stage 1100, where the total power consumption is not less than the value represented by the variable _{Pconnect_limit} , in stage 1130, a timer representing the time since the operation of stage 1080 is compared to a predetermined time limit. In operation 1080 from stage timer indicates a case where the date of expiration time is greater than a predetermined limit, the phase variable _P connect_limit 1150 will reset to the initial value P _disconnect. Therefore, in the case where the predetermined amount of time has expired since the setting of the self-protection band, the guard band is cleared by the action of the stage 1150. The phase 1010 described above is then performed.

In stage 1130, the timer indicates that the time period since the expiration of the operation of stage 1080 is not greater than the predetermined limit, in stage 1140, the priority of the detected feature detected by functional 70 is reviewed. In the event that a parameter that exhibits a higher priority than that determined in stage 1050 and disabled in stage 1070 has been detected, in stage 1150, the variable P _{connect_limit is} reset to the initial value P _disconnect . Thus, in the event that an unpowered PD 20 exhibiting a priority above the disabling has been detected, the guard band is cleared by the action of stage 1150. Stage 1010 described above is then performed. In stage 1140, stage 1090 described above is performed without detecting a defect that is higher than the priority determined in stage 1050 and disabled in stage 1070.

Although the operations of stages 1130, 1140, and 1150 are described as being performed in response to the comparison of stage 1100, this is not meant to be limiting in any way. The operations of stage 1090 and stage 1100 may be performed continuously, wherein the actions of stage 1130 and/or stage 1140 are performed in response to appropriate interruptions or calls, as further described below with respect to Figures 4B, 4C.

4A is a high level flow diagram of the operation of control circuit 60 of FIG. 1 in accordance with the principles of the present invention, in which a planned protection is implemented for a particular chirp in response to a single oscillation event. In stage 2000, the maximum power level available from power source 50 is input. In one embodiment, the maximum power level is communicated from the host 40 to the control circuit 60, and in another embodiment, the maximum power bit rate is communicated directly from the power source 50 to the control circuit 60. A variable labeled P _disconnect is set equal to the maximum available power level. In stage 2010, a flag associated with each _埠 85 is labeled P _{port_connect_limit} for each _埠i , and the variable of _i is initially set equal to P _disconnect .

In phase 2020, the total power consumption of all powered PDs 20 is determined. In an exemplary embodiment, the total power consumption is determined by inputting the output of each current sensor 90 and the output of voltage sensor 100 and multiplying the sum of the currents by the voltage. The current consumption of the Ethernet power manager 10 (and in particular, the control circuit 60) is preferably subtracted as a constant. In an alternate embodiment, the maximum power level provided by host 40 takes into account the current consumption of Ethernet power manager 10.

In stage 2030, control circuit 60 operates detection functionality 70 to detect a PD 20 that is not currently powered. Preferably, control circuit 60 operates the detection functionality to detect unpowered PDs 20 in consideration of all unpowered round robin modes.

In stage 2040, the total power consumption determined in phase 2020 is compared to P _{port_connect_limit,i of 埠} i (in the stage 2030 for which an unpowered PD20 is detected). In the case where the total power consumption is greater than _{Pport_connect_limit,i} , stage 2030 described above is performed. Therefore, in the case where the power consumption is greater than the predetermined limit of the chirp, other chirps whose power consumption may not be greater than the predetermined limit of the other are detected.

In stage 2040, the total power consumption is not greater than P _{port_connect_limit, i} , in the stage 2045, the detected P _{port_connect_limit, i is} set equal to P _disconnect . Therefore, in the case where the total power consumption is less than the guard band (as indicated by P _{port_connect_limit, i} ), the guard band is reset to zero. In stage 2050, control circuit 60 operates respective electrical control switches 80 to connect power to PDs 20 detected in stage 2030. In stage 2060, the total power consumption of all powered PDs 20 is determined in the manner described above with respect to stage 2020.

In stage 2070, the total power consumption determined in stage 2060 is compared to _Pdiss . In the event that the total power consumption is not greater than P _disconnect , phase 2030 described above is performed. In the event that the total power consumption is greater than _Pdiss , in stage 2080, the PD 20 that is to be disabled in response to the overload condition detected in stage 2070 is determined. In one embodiment, the last PD 20 to be powered is determined to be the PD 20 to be disabled according to stage 2050. In another specific example, the lowest priority 目前 currently being powered is determined as the ambiguity of the desire to be disabled. In stage 2090, the power consumption of the PD 20 to be disabled according to stage 2080 is determined. In one embodiment, the power consumption of the PD 20 to be disabled is determined in response to the associated current sensor 90, and in another embodiment, based on the reduced total power compared to the power consumption of stage 2060. Stage 2090 is calculated after consumption of stage 2100. In stage 2100, the power flow of the PD 20 determined in stage 2080 is disabled. In an exemplary embodiment, the power flow is disabled by opening the respective electrical control switch 80.

In stage 2110, the guard band is set to define the connection power limit of the disabling in phase 2100, the operation of which is similar to that described above with respect to _{Pno_more_connect} of Figure 2B. Preferably, the guard band is a function of the power consumption of the disabled powered device as determined in stage 2090. The variable P _{port_connect_limit, i} is set equal to P _disconnect minus the determined guard band. Therefore, the guard band is set by the operation of stage 2110 only if the power consumption has exceeded the initial maximum power level P _disoonnect , and the guard band is set only for the _{回应 that is disabled} in response to the power consumption exceeding the limit. . In one embodiment, the guard band is equal to the power consumption of the powered device that is disabled as determined in stage 2090 plus a predetermined value. In yet another embodiment, the predetermined value is sufficient to prevent oscillation between states, and is preferably set to about 2 watts.

In stage 2120, an interrupt timer is set to automatically clear the guard band set in stage 2110 after a predetermined period of time. In one embodiment, a single interrupt timer is set for all events of phase 2110, and in another embodiment, an individual timer associated with the UI is set for each of the set guard bands. Step 2030 is then performed, which can detect other power supplies that are not powered and power them.

4B is a high level flow diagram of the operation of the control circuit of FIG. 1 in response to the timer set in stage 2120 of FIG. 4A to clear the guard band in accordance with the principles of the present invention. In phase 3000, the time has expired to call the routine. In stage 3010, for the expiration of the timer, P _{port_connect_limit,i is} set to P _disconnect , that is, the guard band is reset to zero. In a specific example of setting a single timer, the guard band is reset to zero for all 埠 after a predetermined period in which stage 2120 is not performed for any 埠. In stage 3020, the routine returns.

4C is a high-level flow diagram of the operation of the control circuit of FIG. 1 in response to detecting that the disabled power supply device is no longer connected to clear the guard band, in accordance with the principles of the present invention. In the event that loop detection in stage 2030 has detected that the disabled phase 2100 is no longer connected, as described in stage 4000, the routine of Figure 4C is called. In stage 4010, for port 85 (which is disabled in phase 2100 of Figure 4A, and phase 2030 has detected that PD 20 is no longer connected for it), set P _{port_connect_limit,i} to P _disconnect , ie, Clear the guard band. Therefore, in the case where the PD 20 that is disabled in response to the overload condition of stage 2070 is disconnected, the guard band is reset to zero.

5 is a high-level diagram of an Ethernet power supply system including an Ethernet power manager 300 that provides power to a plurality of powered devices 20 on a respective communication cable 30, further including a host 40 and a power supply 50. The Ethernet power management unit 300 includes a control circuit 310, a detection function 70 associated with the control circuit 310, a plurality of electrical control switches 80 associated with a particular port 85, and a plurality of variable current limits. The device 320 is illustrated as a plurality of current sensors 90 and a voltage sensor 100 that sense resistors. The control inputs of each of the electrical control switches 80 are coupled to respective outputs of the control circuit 310, and the sense outputs of each of the current sensors 90 are coupled to respective inputs of the control circuit 310, and the variable current limiter The control inputs of each of 320 are coupled to respective outputs of control circuit 310. In a specific example in which each of the current sensors 90 is represented by a sense resistor, as illustrated, each end of the sense resistor 90 is coupled to a respective input control circuit 310.

The output of power supply 50 is connected in parallel to the input of each electrical control switch 80 via a respective current sensor 90. The output of each of the electrical control switches 80 is coupled to the particular PD 20 via a respective variable current limiter 320 via respective ports 85 and respective communication cablings 30. The PD 20 is not required to be connected to each of the ports 85, and as will be further described below, the detection functionality 70 is operable to detect the presence or absence of a connected PD 20. Host 40 is in communication with control circuitry 310. In one embodiment, host 40 is in communication with control circuitry 310 over a network such as an Ethernet network, and in another embodiment, host 40 is directly coupled to control circuitry 310.

Each communication cable 30 can be pluggably connected or directly connected to the Ethernet power management manager 300 at a particular port 85. The combination of voltage sensor 100 and current sensor 90 represents a power sensor operable to determine connection to all PDs 20 of the power source or Ethernet manager 300 when the current sensor 90 is used in combination The total power consumption, and the power consumption of each PD 20 drawn from the Ethernet power manager 300 is determined by the respective current sensor 90.

Although the electrical control switch 80 and the variable current limiter 320 are illustrated as separate components, this is not meant to be limiting in any way. In one embodiment, the electrically controlled switch 80 and the variable current limiter 320 are constructed from a single FET or other opto-electronic synergistic comparator whose gates are controlled to cooperate with the current sensor 90 to alternately generate current limiting functionality: Switch open condition and switch closure.

In operation, control circuit 310 is in communication with host 40 and receives information regarding the maximum power output of power source 50. The control circuit 310 further operates the detection functionality 70 to detect the presence of the active PD 20 connected to each of the ports 85 on the communication cable 30 and to close each other in response to the detection of the active PD 20 connected to the port 85. The switch 80 is electrically controlled whereby power is supplied to the PD 20 over the communication cable 30. Control circuit 310 further sets an appropriate current limit to variable current limiter 320 to limit the current drawn by PD 20 to a predetermined limit. Control circuit 310 is further operative to monitor the power consumption of all powered PDs 20, and (as further explained below) disables at least one PD 20 in response to a power overload. It will be appreciated that power source 50 is preferably used to power all or a maximum number of detected PDs 20 without exceeding their rated maximum capacity.

Host 40 can communicate a request for increased power from one or more PDs 20 received on the network. Control circuit 310 determines whether the increased power will be allocated in response to the request for increased power, total power consumption, and maximum available power. In the event that the increased power is to be allocated, the control circuit 310 responds to the PD 20 with the authorization via the host 40, and in an exemplary embodiment, sets a suitable limit for the increased power to the variable current limiter 320. .

Although the above has been described in a specific example, the variable current limiter 320 is set to an appropriate current limit to perform power allocation to the PD 20 by controlling the current so that it does not exceed a predetermined limit, but this It is not intended to be limiting in any way. In another embodiment, the variable current limiter 320 is only set to a value suitable for control over an overload condition, as described, for example, in the IEEE 802.3af-2003 specification mentioned above.

6 is a high level flow diagram of the operation of control circuit 310 of FIG. 5 in accordance with the principles of the present invention in which a guard band is constructed for all ports 85 of the system in response to a single oscillation event. In stage 5000, the maximum power level available from power source 50 is input. In one embodiment, the maximum power level is communicated from the host 40 to the control circuit 60, and in another embodiment, the maximum power level is communicated directly from the power source 50 to the control circuit 60. A variable labeled P _disconnect is set equal to the maximum available power level. In stage 5010, a variable labeled _{Pconnect_limit} is initially set equal to P _disconnect .

In stage 5020, the total power consumption of all powered PDs 20 is determined. In an exemplary embodiment, the total power consumption is determined by inputting the output of each current sensor 90 and the output of voltage sensor 100 and multiplying the sum of the currents by the voltage. The current consumption of the Ethernet power manager 300 (and in particular, the control circuit 310) is preferably subtracted as a constant. In an alternate embodiment, the maximum power level provided by host 40 takes into account the current consumption of Ethernet power manager 300.

In stage 5030, control circuit 310 operates detection functionality 70 to detect a PD 20 that is not currently powered. Preferably, the control circuit 310 operates the detection functionality to detect the unpowered PDs 20 in consideration of the manner in which all of the unpowered ports 85 are looped. Stage 5030 can also include receiving, via host 40, a request for increased power from one or more PDs 20.

In stage 5040, the total power consumption determined in stage 5020 is compared to _{Pconnect_limit} . In the event that the total power consumption is greater than P _{connect_limit} , stage 5030 described above is performed again. Therefore, in the case where the power consumption is greater than the connection power limit, no request is made to increase the power or supply power to a detected unpowered powered device.

In stage 5040, the total power consumption in the case of not greater than _P connect_limit in _P connect_limit 5050 phase will be reset to the preset value P _disconnect. Thus, where the total power consumption is less than the guard band (as indicated by _{Pconnect_limit} and will be described further below), the guard band is reset to zero. In stage 5060, in the event that the power requested in stage 5030 is a detected unpowered powered device, control circuit 310 operates a respective electrical control switch 80 to connect the power to the detected PD 20. In the case where the power requested in stage 5030 is a powered device requesting increased power, in an exemplary embodiment, control circuit 310 operates respective variable current limiter 320 to increase the PD that requests the increased power. 20 current limit.

In stage 5070, the total power consumption of all powered PDs 20 is determined in the manner described above with respect to stage 5020. In stage 5080, the total power consumption determined in stage 5070 is compared to _Pdiss . In the case where the total power consumption is not greater than P _disconnect , the phase 5030 described above is performed. Thus, where the total power consumption is less than the maximum available power, additional detected powered devices can be powered and/or additional power requests can be granted.

In stage 5080, where the total power consumption is greater than _Pdiss , in stage 5090, the PD 20 that is to be disabled in response to the overload condition detected in stage 5080 is determined. In one embodiment, the PD 20 that is to be de-energized or reduced in power is determined based on the last PD 20 that is to be powered or has increased power in stage 5060. In another embodiment, the lowest priority 目前 currently being powered is determined as the 欲 to disable or reduce the allocated power. In stage 5100, the power consumption of the PD 20 that is to be disabled or reduced in power according to stage 5090 is determined. In one embodiment, the power consumption of the PD 20 to be disabled is determined in response to the associated current sensor 90, and in another embodiment, based on the readings in stage 5120 described below. The power consumption determined by stage 5070 calculates stage 5100 after the operation of stage 5110 described below compared to the reduced total power consumption. In stage 5110, the power flow of the PD 20 as determined in stage 5090 is disabled or reduced. In an exemplary embodiment, the power flow is disabled by opening the respective electrical control switches 80, and the power is reduced by setting the respective variable current limiters 320.

In stage 5120, the total power consumption of all powered PDs 20 is determined. In an exemplary embodiment, the total power consumption is determined by inputting the output of each current sensor 90 and the output of voltage sensor 100 and multiplying the sum of the currents by the voltage. The current consumption of the Ethernet power manager 300 (and in particular, the control circuit 310) is preferably subtracted as a constant. In an alternate embodiment, the maximum power level provided by host 40 takes into account the current consumption of Ethernet power manager 300.

In stage 5130, the total power consumption determined in stage 5120 is compared to _Pdiss . In the case where the total power consumption is greater than P _disconnect (ie, the operation of stage 5110 is not sufficient to reduce the power consumption below the overload of P _disconnect ), performing phase 5090 described above to disable another 85, or reduce The power of another PD 20.

In 5130, where the total power consumption is not greater than _Pdiss , in stage 5140, the guard band is set to define a connection power limit, the operation of which is similar to that described above with respect to _{Pno_more_connect} of Figure 2B. Preferably, the guard band is a function of the power consumption of the disabled powered device as determined in stage 5090. The variable P _{connect_limit} is set equal to P _disconnect minus the determined guard band. In one embodiment, the guard band is equal to the power consumption or reduced power of the powered device that is disabled as determined in stage 5100 plus a predetermined value. In yet another embodiment, the predetermined value is sufficient to prevent oscillation between states, and is preferably set to about 2 watts.

In stage 5150, an interrupt timer is set to automatically clear the guard band set in stage 5140 after a predetermined period of time. Step 5030 is then performed, which can detect and power other unpowered ports, or increase power as requested.

Thus, this embodiment enables a method of dynamically allocating a guard band in response to a PD that is powered and then disabled by power management functionality, the power management functionality indicating that the PD is powered after being powered The total power is greater than the maximum available power. In one specific example, the guard band is set for all ports of the system, and in another example, the guard band is set for the disabled.

In a specific example of setting a guard band on a system-wide basis, the guard band is cleared by one of: the total power consumption is less than the total available power minus the guard band; and one PD is connected to one with a higher power than The priority of managing the functional and disabling priority; and a predetermined period of time has expired.

In a specific example of setting a guard band for the disabled, the guard band is cleared by one of the following: a detection period in which no PD connected to the PD associated with the disabled is detected. A predetermined period of time has expired; and the total power consumption is less than the total available power minus the guard band.

It is understood that the specific features of the invention described in the context of the specific embodiments of the invention may Rather, the various features of the invention which are described in the context of a particular embodiment for the purpose of brevity may be provided separately or in any suitable sub-combination.

All technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the art. Although methods similar or equivalent to those described herein can be used in the practice or teaching of the present invention, suitable methods are described herein.

All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In the event of a conflict, the patent specification, including definitions, will prevail. In addition, the materials, methods, and examples are illustrative only and are not intended to be limiting.

It will be appreciated by those skilled in the art that the present invention is not limited to the particulars shown and described herein. Rather, the scope of the present invention is defined by the scope of the appended claims, and includes the combinations and sub-combinations of the various features described herein, as well as those skilled in the <RTIgt; Changes and modifications to the invention that do not exist.

10. . . Ethernet Power Manager

20. . . Powered device

30. . . Communication cabling

40. . . Host

50. . . power supply

60. . . Control circuit

70. . . Detection functionality

80. . . Electric control switch

85. . . port

90. . . Current sensor / sense resistor

100. . . Voltage sensor

200. . . line

210. . . line

220. . . point

230. . . line

240. . . line

250. . . point

300. . . Ethernet Power Manager

310. . . Control circuit

320. . . Variable current limiter

1 is a high-level diagram of an Ethernet power supply system including an Ethernet power manager that provides power to a plurality of powered devices on a communication cable; FIG. 2A is a power supply according to the prior art. Description of the powered device that is overloaded and oscillated between the powered state and the disabled state; and FIG. 2B is a description of the guard band preventing the oscillation of FIG. 2A according to the prior art.

3 is a high-level flow diagram of the operation of the control circuit of FIG. 1 in accordance with the principles of the present invention, in which a guard band is constructed for all of the systems in response to a single oscillator event; FIG. 4A is a diagram of FIG. 1 in accordance with the principles of the present invention. A high-level flow diagram of the operation of the control circuit, wherein the protection of the particular 埠 is implemented in response to a single oscillating event; FIG. 4B is an illustration of the operation of the control circuit of FIG. 1 in response to a timer to clear the guard band in accordance with the principles of the present invention. High-level flowchart; FIG. 4C is a high-level flowchart of the operation of the control circuit of FIG. 1 in response to detecting that the powered device that is disabled is no longer connected to clear the guard band in accordance with the principles of the present invention; FIG. A high-level diagram of an Ethernet power supply system of the principles of the invention, the system comprising an Ethernet power manager that provides power to a plurality of powered devices over a communication cable, each of the modules comprising a Electrically controlled switch and a variable current limiter; and Figure 6 is a high level flow diagram of the operation of the control circuit of Figure 5 in response to a single oscillation event in accordance with the principles of the present invention Construction of a guard band for all port systems.

Claims (21)

A method for controlling an Ethernet power supply system, the method comprising: sequentially supplying a plurality of powered devices on a communication cable; and determining a first total power consumption in response to power supply of the plurality of powered devices; Determining the power of at least one of the plurality of powered devices being powered, thereby reducing power consumption below the predetermined maximum, if the determined first total power consumption exceeds a predetermined maximum power level a power level; determining a power consumption of the at least one powered device that is disabled; and determining, in response to the disabled power, a connection power limit that is lower than the maximum power level by a guard band, wherein the guard band is a function of the determined power consumption of the at least one powered device having the power disabling; monitoring a second total power consumption after the disabling power; and only monitoring the second total power consumption less than In the case of the connection power limit, the power is enabled to a powered device. The method of claim 1, further comprising: setting the guard band to zero after a predetermined period from the disabling power. The method of claim 1, further comprising: detecting an unpowered powered device that is prioritized over a priority associated with at least one powered device having the power disabling Associated; and The guard band is set to zero in response to the detected powered device. The method of claim 1, further comprising: detecting a request for increasing power allocated to a powered device, the powered device and the at least one powered device having the power disabled The priority associated with the priority is associated; and the guard band is set to zero in response to the detected request. The method of claim 1, further comprising setting the guard band to zero if the monitored second total power consumption is less than the connection power limit. The method of claim 1, wherein the at least one powered device having the power disability comprises one of: sequentially supplying one of a plurality of powered devices to be powered by the device; and the sequence Powering one of the plurality of powered devices to the lowest priority powered device. The method of claim 1, wherein the enabling power comprises increasing a power allocated to the powered device. A method for controlling an Ethernet power supply system, the method comprising: sequentially supplying a plurality of powered devices on a communication cable; determining a total power consumption in response to the power supply of the plurality of powered devices; Determining, when the first total power consumption exceeds a predetermined maximum power level, disabling power of at least one of the plurality of powered devices, thereby reducing power consumption to be lower than the predetermined maximum power Level; determining power consumption when powering each of the at least one powered device; and determining a connection power limit lower than the maximum power level by a power band in response to the disabled power Wherein the defined connection power limit is associated with each powered device having the power disabling, the defined connection power limit being separately defined for each disabled at least one powered device as the premises Determining a function of power consumption; monitoring a second total power consumption after the disabling power; and enabling the power to be only one if the monitored second total power consumption is less than the connection power limit Power supply equipment. A method for controlling an Ethernet power supply system, the method comprising: sequentially supplying a plurality of powered devices on a communication cable, each of the plurality of powered devices being associated with a unique device; Responding to the power supply of the plurality of powered devices to determine a total power consumption; and disabling one of the plurality of powered devices if the determined total power consumption exceeds a predetermined maximum power level Power; in response to the disabling power, defining a connection power limit that is lower than the maximum power level by a guard band, the guard band being associated with the unique port, the unique port and the powered device having the power disability The device is associated; after the disabled power, the total power consumption is monitored; and if the total power consumption monitored after the disabled power is less than the connection power limit, the powered device having the power disability is powered. The method of claim 9, further comprising: detecting that the powered device is not connected to the unique device associated with the powered device having the power disable; and responding to the detecting that the powered device is not Connect to set the guard band to zero. The method of claim 9, further comprising: setting the guard band to zero in response to one of: the monitored total power consumption is less than the connection power limit; and from the disabling power After a predetermined period. An Ethernet power supply manager, comprising: an Ethernet power supply control circuit; a plurality of ports, each of the ports having a response thereto in response to the Ethernet power supply control circuit And one of a switch and a variable current limiter; and at least one power sensor in communication with the Ethernet power control circuit and operative to sense that each of the plurality of ports is captured The power supply control circuit is configured to: sequentially supply a plurality of powered devices connected to a specific one of the plurality of ports on the communication cable; and respond to the sequential power supply The plurality of powered devices determine a first total power consumption by the at least one power sensor; and wherein the determined first total power consumption exceeds a predetermined maximum power level, by a switch And the associated one in a variable current limiter Operating to disable the power of at least one of the plurality of powered devices, thereby reducing power consumption below the predetermined maximum power level; when operating the disabled at least one powered device, Determining power consumption; determining, in response to the disabling power, a connection power limit lower than the maximum power level by a guard band, wherein the guard band is a portion of the at least one powered device having the power disabling Determining a function of power consumption; after the disabled power, monitoring a second total power consumption by the at least one power sensor; and only if the monitored second total power consumption is less than the connection power limit In the case, the power to a powered device is enabled by the associated one of a switch and a variable current limiter. The Ethernet power supply manager of claim 12, wherein the Ethernet power supply control circuit is further operative to set the guard band to zero in response to one of: from the disability of the power a predetermined time; and the monitored second total power consumption is less than the connection power limit. The Ethernet power supply manager of claim 12, further comprising a response function responsive to the Ethernet power supply control circuit, wherein the Ethernet power supply control circuit is further operated to: Detecting, by the detection functionality, an unpowered powered device that is associated with a priority that is higher than a priority associated with the disabled at least one powered device; and The guard band is set to zero in response to the detected powered device. The Ethernet power supply manager of claim 12, wherein the Ethernet power supply control circuit is further configured to: detect a request for increasing power allocated to a powered device, the powered device and the A higher priority than the priority associated with the disabling of at least one of the powered devices; and setting the guard band to zero in response to the detected request. The Ethernet power supply manager of claim 12, wherein the at least one powered device comprises one of: sequentially supplying a last powered device of the plurality of powered devices; and A lowest priority powered device among the plurality of powered devices is sequentially powered. The Ethernet power supply manager of claim 12, wherein the power enabling comprises adding a distributed power to the powered device by setting the variable current limiter. An Ethernet power management device includes: an Ethernet power supply control circuit; a plurality of ports, each of the switches having a switch associated with the Ethernet power supply control circuit associated therewith And one of a variable current limiter; and at least one power sensor in communication with the Ethernet power control circuit and operative to sense the captured via each of the plurality of ports One The amount of power, the Ethernet power supply control circuit is operative to: sequentially supply a plurality of powered devices connected to a particular one of the plurality of turns on the communication cable; and respond to the plurality of power supplies sequentially The first power consumption is determined by the at least one power sensor by the powered device; and the switch and the first one are determined by the first total power consumption exceeding a predetermined maximum power level The operation of the associated one of the variable current limiters to disable the power of at least one of the plurality of powered devices, thereby reducing power consumption below the predetermined maximum power level; Determining, by the at least one power sensor, the power consumption of the disabled one of the at least one powered device; determining a connection power lower than the maximum power level by a guard band in response to the disabled power a limit, wherein the defined connection power limit is associated with each powered device of the power disabling, the defined connection power limit being at least one for each disability as a function of the determined power consumption The power supply device is separately defined; after the disabled power, the second total power consumption is monitored by the at least one power sensor; and only the second total power consumption monitored is less than the connection power limit In the case, the power to a powered device is enabled by the associated one of a switch and a variable current limiter. An Ethernet power manager that includes: An Ethernet power control circuit; a plurality of ports, each of the ports having an electrical control switch associated with the Ethernet power control circuit; and at least one power sensor Communicating with the Ethernet power control circuit and operating to sense an amount of power drawn through each of the plurality of turns, the Ethernet power control circuit operates to: on the communication cabling Supplying power to a plurality of powered devices each connected to a particular one of the plurality of turns; determining a first total power consumption by the at least one power sensor in response to the powering a plurality of powered devices; Determining, by the operation of the associated electrical control switch, the power of one of the plurality of powered devices; in response to the loss, the determining that the first total power consumption exceeds a predetermined maximum power level And a power limit for defining a connection power limit associated with the one of the disabled devices in the powered device, the connection power limit being lower than the maximum power level by a guard band; after that Monitoring a second total power consumption by the at least one power sensor; and enabling the electrical control switch by the associated electrical control switch only if the monitoring second total power consumption is less than the connection power limit The power of the one that is disabled in the powered device. The Ethernet power supply manager of claim 19, further comprising a response function responsive to the Ethernet power supply control circuit The Ethernet power control circuit is further configured to: detect, by the detection function, that the powered device is not connected to the device associated with the powered device having the power disable; and respond to the The guard band is set to zero for detection. The Ethernet power supply manager of claim 19, wherein the Ethernet power control circuit is further operative to set the guard band to zero in response to one of: the monitored total power consumption is less than the The power limit is connected; and a predetermined time elapses from the disabling of the power.