CN117792807A - Power over Ethernet method, switch and storage medium - Google Patents
Power over Ethernet method, switch and storage medium Download PDFInfo
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- CN117792807A CN117792807A CN202311815882.2A CN202311815882A CN117792807A CN 117792807 A CN117792807 A CN 117792807A CN 202311815882 A CN202311815882 A CN 202311815882A CN 117792807 A CN117792807 A CN 117792807A
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Abstract
The embodiment of the application discloses an Ethernet power supply method, a switch and a storage medium; the method is used in the technical field of power over Ethernet. In the embodiment of the application, the cable length of the communication cable between the switch and the terminal is obtained; determining a voltage drop of the communication cable based on a cable length of the communication cable and a load current of the terminal; and adjusting the output voltage of the switch for supplying power to the terminal based on the preset working voltage range of the terminal and the voltage drop of the communication cable. The output voltage of the switch for supplying power to the terminal is regulated through the voltage drop of the communication cable between the switch and the terminal and the preset working voltage range of the terminal, and when the transmission distance between the switch and the terminal is any distance, the voltage received by the terminal can be kept within the preset working voltage range of the terminal, so that the normal operation of the terminal is ensured.
Description
Technical Field
The embodiment of the application relates to the technical field of power over ethernet, in particular to a power over ethernet method, a switch and a storage medium.
Background
In the existing PoE (Power over Ethernet ) system, a power supply end is a switch, a power receiving end is a terminal, such as a wireless AP, a network camera, and the like, and in the power over ethernet process, power supply and data transmission are performed between the switch and the terminal through a communication cable (such as a twisted pair cable or a photoelectric hybrid cable, and the like).
When the switch supplies power to the terminal through the communication cable, determining a voltage value received by the terminal based on an output voltage value of the switch and the length of the communication cable between the switch and the terminal; in general, when the output voltage value of the switch is fixed, the longer the transmission distance between the terminal and the switch is, the longer the communication cable is, the smaller the voltage value received by the terminal is; the closer the transmission distance between the terminal and the exchange is, the shorter the communication cable is, and the larger the voltage value received by the terminal is.
And the terminal has corresponding working voltage range, if the transmission distance between the switch and the terminal is too far or too close, the voltage value received by the terminal is easy to exceed the working voltage range, and the normal operation of the terminal is influenced.
Disclosure of Invention
The embodiment of the application provides an Ethernet power supply method, a switch and a storage medium, which can enable voltage received by a terminal to be kept within a preset working voltage range of the terminal when the transmission distance between the switch and the terminal is any distance, so that normal operation of the terminal is ensured.
The embodiment of the application provides a power over ethernet method, which is applied to a switch, wherein the switch supplies power to a terminal through a communication cable, and the method comprises the following steps:
acquiring the cable length of a communication cable between the switch and the terminal;
determining a voltage drop of the communication cable based on a cable length of the communication cable and a load current of the terminal;
and adjusting the output voltage of the switch for supplying power to the terminal based on the preset working voltage range of the terminal and the voltage drop of the communication cable.
Further, the obtaining the cable length of the communication cable connected to the switch includes:
transmitting a first pulse signal to the terminal through the communication cable, and receiving a second pulse signal reflected to the switch by the terminal through the communication cable; the second pulse signal is a pulse signal reflected back to the switch after the first pulse signal reaches the terminal;
the cable length of the communication cable is determined based on a time interval from the switch sending the first pulse signal to receiving the second pulse signal.
Further, the determining the voltage drop of the communication cable based on the cable length of the communication cable and the load current of the terminal includes:
determining a cable resistance of the communication cable based on a cable length of the communication cable;
a voltage drop of the communication cable is determined based on a cable resistance of the communication cable and a load current of the terminal.
Further, the determining the cable resistance of the communication cable based on the cable length includes:
acquiring a cable cross-sectional area of the communication cable;
a cable resistance of the communication cable is determined based on a cable cross-sectional area of the communication cable and a cable length of the communication cable.
Further, the adjusting the output voltage of the switch to supply power to the terminal based on the preset working voltage range of the terminal and the voltage drop of the communication cable includes:
and based on the preset working voltage range of the terminal and the voltage drop of the communication cable, sending a pulse width modulation signal to a feedback pin end of a power module of the switch, and controlling the feedback voltage of the feedback pin end of the power module to regulate the output voltage of a voltage output end of the power module.
Further, the sending a pulse width modulation signal to a feedback pin end of the power module based on the preset working voltage range of the terminal and the voltage drop of the communication cable includes:
selecting any working voltage from a preset working voltage range of the terminal as the working voltage required by the terminal;
and sending a pulse width modulation signal to a feedback pin end of the power module based on the working voltage required by the terminal and the voltage drop of the communication cable.
Further, the method further comprises the following steps:
detecting whether the terminal is a power receiving end device meeting the power over Ethernet condition based on a preset pulse detection rule;
if so, the switch supplies power to the terminal through the communication cable.
The embodiment of the application also provides a switch, which comprises: a power module and a processor;
the voltage output end of the power supply module is connected with a communication cable, the voltage output end of the power supply module is connected with a feedback pin end of the power supply module, the power supply module supplies power to the terminal through the communication cable, and the feedback pin end of the power supply module is used for feeding back the output voltage of the voltage output end of the power supply module;
the processor is connected with the feedback pin end of the power supply module and used for acquiring the cable length of the communication cable between the switch and the terminal; and determining the voltage drop of the communication cable based on the cable length of the communication cable and the load current of the terminal, and sending a pulse width modulation signal to a feedback pin end of the power module based on the preset working voltage range of the terminal and the voltage drop of the communication cable to control the feedback voltage of the feedback pin end of the power module so as to adjust the output voltage of the voltage output end of the power module.
Further, the method further comprises the following steps: the voltage dividing module and the filtering module;
the processor is connected with a feedback pin end of the power supply module through the filtering module;
the voltage output end of the power supply module is connected with the feedback pin end of the power supply module through the voltage dividing module.
Embodiments also provide a computer readable storage medium comprising instructions that when executed on a computer cause the computer to perform a power over ethernet method as described above.
From the above technical solutions, the embodiments of the present application have the following advantages:
in the embodiment of the application, the cable length of the communication cable between the switch and the terminal is obtained; determining a voltage drop of the communication cable based on a cable length of the communication cable and a load current of the terminal; and adjusting the output voltage of the switch for supplying power to the terminal based on the preset working voltage range of the terminal and the voltage drop of the communication cable. The output voltage of the switch for supplying power to the terminal is regulated through the voltage drop of the communication cable between the switch and the terminal and the preset working voltage range of the terminal, and when the transmission distance between the switch and the terminal is any distance, the voltage received by the terminal can be kept within the preset working voltage range of the terminal, so that the normal operation of the terminal is ensured.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings that are needed in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments described in the present application, and other drawings may be obtained according to these drawings for a person having ordinary skill in the art.
FIG. 1 is a power over Ethernet flowchart of an embodiment of the present disclosure;
FIG. 2 is another power over Ethernet flowchart disclosed in an embodiment of the present application;
fig. 3 is a schematic connection diagram of an optical-electrical hybrid cable according to an embodiment of the present disclosure;
fig. 4 is a circuit configuration diagram of a switch according to an embodiment of the present application.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the present application more apparent, the present application will be described in further detail with reference to the accompanying drawings, and the described embodiments should not be construed as limiting the present application, and all other embodiments obtained by those skilled in the art without making any inventive effort are within the scope of the present application.
In the following description, reference is made to "one embodiment" or "one embodiment" and the like, which describe a subset of all possible embodiments, but it is to be understood that "one embodiment" or "one embodiment" may be the same subset or a different subset of all possible embodiments and may be combined with each other without conflict. In the following description, the term plurality refers to at least two.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing embodiments of the present application only and is not intended to be limiting of the present application.
In the existing PoE (Power over Ethernet ) system, a Power Sourcing Equipment (PSE) is a switch, a Powered Device (PD) is a terminal, and data transmission and power supply are performed between the switch and the terminal through a communication cable. When the switch supplies power to the terminal through the communication cable, determining a voltage value received by the terminal based on an output voltage value of the switch and the length of the communication cable between the switch and the terminal; in general, when the output voltage value of the switch is fixed, the longer the transmission distance between the terminal and the switch is, the longer the communication cable is, the smaller the voltage value received by the terminal is; the closer the transmission distance between the terminal and the exchange is, the shorter the communication cable is, and the larger the voltage value received by the terminal is. And the terminal has corresponding working voltage range, if the transmission distance between the switch and the terminal is too far or too close, the voltage value received by the terminal is easy to exceed the working voltage range, and the normal operation of the terminal is influenced. The power over ethernet method can keep the voltage received by the terminal within the preset operating voltage range of the terminal when the transmission distance between the switch and the terminal is any distance, so as to ensure the normal operation of the terminal, as shown in fig. 1, specifically comprising steps 101 to 103:
101. the cable length of the communication cable between the switch and the terminal is obtained.
The Ethernet power supply method is applied to a switch, a communication cable is connected between the switch and a terminal, the communication cable comprises a data transmission line and a power wire, the switch supplies power to the terminal through the power wire of the communication cable, and the data transmission line of the communication cable is used for data transmission between the switch and the terminal. The switch is a network device for forwarding an electrical (optical) signal, and may provide an independent electrical (optical) signal path for any two network nodes accessing the switch, where the switch may be a box switch or a frame switch, and is not limited herein. The terminal may be an electronic device such as a wireless AP, a network camera, a network telephone, a palm computer, etc., which is not limited herein. In general, when the switch only needs data transmission, the distance of the data transmission is not limited; however, when the switch supplies power, the power supply transmission distance of the communication cable is limited due to the influence of the voltage drop of the communication cable; the power supply and the data transmission of the switch share the same communication cable, and the data transmission distance of the communication cable is limited because the power supply transmission distance of the communication cable is limited.
The communication cable can be an optical-electrical hybrid cable or a twisted pair, and is not limited herein; in general, the length of the twisted pair is not allowed to exceed 100m due to the limitation of transmitting electric signal data, i.e. the transmission distance between the switch and the terminal is not allowed to exceed 100m; when the photoelectric hybrid cable is adopted for power supply and data transmission, the voltage of the switch is generally a fixed voltage value power supply and is limited by the voltage drop of the photoelectric hybrid cable, the length of the photoelectric hybrid cable is generally not more than 300m, namely the transmission distance between the switch and the terminal is generally not more than 300m, and when the transmission distance of the photoelectric hybrid cable is far, the voltage drop of the photoelectric hybrid cable is too large, so that the working voltage of the terminal is easy to be incapable of meeting the requirements; i.e. the transmission distance between the exchange and the terminal is limited due to the pressure drop effect of the communication cable.
The switch may obtain the cable length of the communication cable between the switch and the terminal, and specifically, the cable length of the communication cable may be obtained through TDR (time domain reflectometry) technology, or through manual input, which is not limited herein.
102. The voltage drop of the communication cable is determined based on the cable length of the communication cable and the load current of the terminal.
After obtaining the cable length of the communication cable, determining a voltage drop of the communication cable based on the cable length of the communication cable and the load current of the terminal; it is understood that the load current of the terminal may be understood as the output current of the switch or the cable current of the communication cable between the switch and the terminal, and the current output by the switch will not generally change when the current is transmitted to the load of the terminal through the communication cable. The load current of the terminal may be obtained by collecting the current on the communication cable, or the terminal, through a current sensor, which is not limited herein.
In general, the load current of the terminal is the output current of the switch, and if the cable length of the communication cable is longer, the voltage drop of the communication cable is larger, and if the cable length of the communication cable is shorter, the voltage drop of the communication cable is smaller.
103. And adjusting the output voltage of the switch for supplying power to the terminal based on the preset working voltage range of the terminal and the voltage drop of the communication cable.
After the voltage drop of the communication cable is obtained, the output voltage of the switch for supplying power to the terminal can be adjusted based on the preset working voltage range of the terminal and the voltage drop of the communication cable, so that the voltage received by the terminal is within the preset working voltage range of the terminal. The upper limit working voltage of the terminal can be obtained through detection; if the working voltage of the terminal is greater than the upper limit working voltage or the working voltage of the terminal is less than the lower limit working voltage, the terminal has working faults; and determining a preset working voltage range of the terminal based on the upper limit working voltage and the lower limit working voltage, namely taking a voltage range formed by the upper limit working voltage and the lower limit working voltage as the preset working voltage range of the terminal.
It will be appreciated that the received voltage at the terminals varies due to the different cable lengths of the communication cables. When the final voltage value reaching each terminal is powered by a fixed power supply, the final voltage value of the terminal may be lower because the voltage of the terminal is close to the upper limit working voltage or the lower limit working voltage of the terminal due to the cable length of the communication cable, so that the anti-interference capability of the terminal is weaker; namely, when the external of the terminal is interfered, the working voltage of the terminal is easy to exceed the upper limit working voltage or the lower limit working voltage, and the normal operation of the terminal is influenced. Namely, when the voltage reaching the terminal is close to the upper limit working voltage or the lower limit working voltage of the terminal of the required voltage, when the external interference exists, the working voltage of the terminal is easy to exceed the working range, so that the terminal equipment is restarted and even damaged.
In the embodiment of the application, after the preset working voltage range of the terminal is obtained, the output voltage of the switch can be adjusted, so that the voltage transmitted to the terminal after the output voltage of the switch is subjected to voltage drop of the communication cable is within the preset working voltage range of the terminal.
In the embodiment of the application, the cable length of the communication cable between the switch and the terminal is obtained; determining a voltage drop of the communication cable based on a cable length of the communication cable and a load current of the terminal; and adjusting the output voltage of the switch for supplying power to the terminal based on the preset working voltage range of the terminal and the voltage drop of the communication cable. The output voltage of the switch for supplying power to the terminal is regulated through the voltage drop of the communication cable between the switch and the terminal and the preset working voltage range of the terminal, and when the transmission distance between the switch and the terminal is any distance, the voltage received by the terminal can be kept within the preset working voltage range of the terminal, so that the normal operation of the terminal is ensured.
In one embodiment, as shown in fig. 3, when the communication cable is a photoelectric hybrid cable, data (signals) and power are separately transmitted, the data transmission line adopts optical transmission, the power supply wire adopts copper wires or aluminum wires to supply power, and the data transmission can reach tens of kilometers theoretically through optical fiber transmission. When the photoelectric hybrid cable is used for long-distance transmission, the main bottleneck is voltage drop when power is supplied by the power supply wire.
In the embodiment of the application, after the switch is initialized, the cable length of the photoelectric hybrid cable can be obtained through the TDR technology, connection communication is established between the switch and the terminal, and the terminal is detected and classified. And after the switch communicates with the terminal, acquiring the load current of the terminal. According to the cable length of the photoelectric hybrid cable and the load current of the terminal, the power supply voltage (output voltage of the switch) of a self-adaptive power supply in the switch is regulated, the power supply voltage is transmitted to a power supply end (DC-DC) of the terminal through the photoelectric hybrid cable, and finally the voltage of a terminal load is in a preset working voltage range of the terminal; according to the scheme, the voltage regulating technology does not need to obtain final voltage of the terminal and then regulate, the power supply voltage can be regulated after the cable length and the load current between the switch and the terminal are obtained, the terminal and the switch do not need to be subjected to complex feedback regulation, the regulation mode is unidirectional regulation, and the mode is simple and efficient. When the voltage of the terminal caused by the voltage drop on the photoelectric hybrid cable does not meet the preset working voltage range of the terminal, the switch and the terminal can be installed at a common working distance and can be installed at an ultra-long distance by adjusting the power supply voltage of the switch.
Further, the power over ethernet flow of the switch will be described in detail below, as shown in fig. 2, specifically including steps 201 to 204.
201. The cable length of the communication cable is determined based on the duration of the reflection of the pulse signal on the communication cable.
The switch may determine the cable length of the communication cable based on the length of reflection of the pulse signal on the communication cable. Specifically, the switch can send a first pulse signal to the terminal through the communication cable, and receive a second pulse signal reflected to the switch by the terminal through the communication cable; the second pulse signal is a pulse signal reflected back to the switch after the first pulse signal reaches the terminal. It can be understood that when the switch sends out the pulse signal, the pulse signal is transmitted on the power wire of the communication cable, and when the pulse signal is transmitted to the terminal, the power wire is in an approximately open state at the terminal because the terminal is not electrified and the power wire is a power input signal, and after the pulse signal reaches the terminal, the pulse signal is reflected to the switch. The cable length of the communication cable is determined based on the time interval from the switch sending the first pulse signal to the receiving the second pulse signal, i.e. the cable length of the communication cable can be measured by the time interval and the rate at which the pulse signal is transmitted over the power conductor of the communication cable.
202. The cable resistance of the communication cable is determined based on the cable length of the communication cable.
After obtaining the cable length of the communication cable, the cable resistance of the communication cable may be determined based on the cable length of the communication cable; specifically, a cable cross-sectional area of the communication cable may be obtained; the cable resistance of the communication cable is determined based on the cable cross-sectional area of the communication cable and the cable length of the communication cable. It will be appreciated that the power conductors in the communications cable are used to supply power, the cable resistance of the communications cable being the wire resistance of the power conductors in the communications cable, the cable cross-sectional area being the cross-sectional area of the power conductors of the communications cable. The wire resistance R of the communication cable can be obtained using the wire resistance formula r=ρ×l/S; where ρ is the resistivity of the communication cable, L is the cable length of the communication cable, and S is the cable cross-sectional area of the communication cable.
203. The voltage drop of the communication cable is determined based on the cable resistance of the communication cable and the load current of the termination.
After determining the cable resistance of the communication cable, the voltage drop of the communication cable can be determined based on the cable resistance of the communication cable and the load current of the terminal; wherein, the communication protocol between the exchanger and the terminal can be realized, and the maximum power and the maximum current (load current of the terminal) of the terminal can be obtained before power supply; according to u=i×r; (I is the load current of the terminal, R is the cable resistance of the communication cable), the voltage drop U of the communication cable can be obtained.
204. And sending a pulse width modulation signal to a feedback pin end of a power module of the switch based on a preset working voltage range of the terminal and a voltage drop of the communication cable.
It can be appreciated that the power supply voltage acceptable by the terminal has a certain preset operating voltage range, and after determining the voltage drop of the communication cable, the output voltage of the switch can be adjusted based on the preset operating voltage range of the terminal and the voltage drop of the communication cable. The switch comprises an adjustable power module, wherein the power module is provided with a voltage output end and a feedback lead angle end, the voltage output end is used for outputting voltage to the communication cable, and the feedback lead angle end is used for feeding back the output voltage of the voltage output end. The pulse width modulation signal can be sent to the feedback pin end of the power module of the switch based on the preset working voltage range of the terminal and the voltage drop of the communication cable, and the feedback voltage of the feedback pin end of the power module is controlled to regulate the output voltage of the voltage output end of the power module. It can be understood that when the output voltage needs to be increased, a pulse width modulation signal with larger width can be sent to the feedback pin terminal, so that the voltage of the feedback pin terminal is raised; when the output voltage needs to be reduced, a pulse width modulation signal with smaller width can be sent to the feedback pin terminal, and the voltage of the feedback pin terminal is pulled down.
Wherein, any working voltage can be selected from the preset working voltage range of the terminal as the working voltage required by the terminal; and based on the working voltage required by the terminal and the voltage drop of the communication cable, sending a pulse width modulation signal to a feedback pin end of the power module, and adjusting the output voltage of the power module of the switch so that the voltage reaching the terminal is the working voltage required by the terminal.
Therefore, in the embodiment of the application, the power module of the adjustable switch is used, the output voltage of the power module of the switch is adjusted based on the cable length by detecting the cable length of the communication cable between the switch and the terminal, so that the voltage reaching the terminal is always kept in the preset working voltage range of the terminal no matter the cable transmission distance, and the reliability and the stability of the whole system are greatly improved.
In one embodiment, it is necessary to detect whether the terminal connected to the switch is a real powered device, so as to avoid power failure; specifically, whether the terminal is a power receiving end device meeting the power over ethernet condition or not can be detected based on a preset pulse detection rule, that is, whether the terminal is a power receiving end device supporting the power over ethernet standard or not is determined; if yes, the switch performs Ethernet power supply to the terminal through the communication cable, and if not, the switch does not perform Ethernet power supply to the terminal.
The embodiment of the application also provides a switch, as shown in fig. 4, which comprises a power module (DC-DC chip) 401 and a processor (CPU) 402; the voltage output end SW of the power module 401 is connected with a communication cable, the voltage output end SW of the power module 401 is connected with the feedback pin end FB of the power module, the power module 401 supplies power to the terminal through the communication cable, and the feedback pin end FB of the power module 401 is used for feeding back the output voltage of the voltage output end SW of the power module 401; i.e. the supply voltage of the switch output is determined by the feedback pin FB of the power module 401.
The processor 402 is connected with the feedback pin terminal FB of the power module 401 and is used for acquiring the cable length of the communication cable between the switch and the terminal; and determining the voltage drop of the communication cable based on the cable length of the communication cable and the load current of the terminal, and sending a pulse width modulation signal (PWM wave) to a feedback pin end of the power module based on the preset working voltage range of the terminal and the voltage drop of the communication cable to control the feedback voltage of a feedback pin end FB of the power module so as to regulate the output voltage of a voltage output end of the power module. That is, when the output voltage of the switch needs to be regulated, the PWM waveform is output to the feedback pin FB of the power module 401 through the pulse modulation output terminal A1 of the processor 402 to regulate the output voltage.
It is understood that the switch further includes a signal transmission module 403, which includes a first NMOS transistor Q1, a second NMOS transistor Q2, and corresponding resistors R3 and R4. The process of obtaining the cable length of the communication cable between the switch and the terminal may be that the pulse signal sent by the signal output end B1 of the processor 402 arrives at the communication cable through the first NMOS tube Q1, and arrives at the signal input end C1 of the processor 402 through the first NMOS tube Q1 and the second NMOS tube Q2; the reflected pulse signal on the communication cable reaches the signal input end C1 of the processor 402 through the second NMOS tube Q2, the time interval of 2 times of pulse signals reaching the signal input end C1 of the processor 402 is recorded, and the length of the communication cable can be calculated by calculating the interval time length according to the TDR technology.
Further, the switch further includes: a filtering module 404 and a voltage dividing module 405; the filtering module 404 is an RC circuit composed of a resistor R3 and a capacitor C2, and the processor 402 is connected with a feedback pin end of the power module 401 through the filtering module 404; that is, the pulse width modulation signal (PWM wave) output by the pulse modulation output terminal A1 of the processor 402 is superimposed on the feedback pin terminal FB of the power module 401 after being filtered by the filtering module 404, so as to realize the adjustment of the output voltage of the power module 401. The voltage division module 405 includes a capacitor C1, a resistor R1 and a resistor R2; the voltage output terminal SW of the power module 401 is connected to the feedback pin terminal FB of the power module 401 through the voltage dividing module 405. The output voltage of the voltage output terminal SW of the power module 401 is fed back to the feedback pin terminal FB of the power module 401 through the divided voltage values of the resistors R1 and R2. The processor 402 is further connected to the enable terminal EN of the power module 401, and is configured to control the power module 401 to output or not output a voltage.
The embodiment of the application provides an exchange of integrated adjustable power module, measures the cable length of communication cable between exchange and terminal through the TDR technique to confirm the voltage drop of communication cable between exchange and the terminal, adjust the output voltage of the power module of exchange based on the voltage drop of communication cable, make the voltage of terminal no matter installation distance, all can keep within the preset operating voltage scope of terminal. The power supply voltage can be flexibly regulated in the switch, and the influence of the ultra-long-distance installation between the switch and the terminal on power supply is eliminated. The output voltage of the switch can be automatically regulated, so that the voltage of the terminal can be kept within a reasonable range no matter the installation distance, and the reliability and the anti-interference capability of the whole switch power supply system are improved.
It will be clear to those skilled in the art that, for convenience and brevity of description, specific working procedures of the above-described systems, apparatuses and units may refer to corresponding procedures in the foregoing method embodiments, which are not repeated herein.
In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods may be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative, e.g., the division of the units is merely a logical function division, and there may be additional divisions when actually implemented, e.g., multiple units or components may be combined or integrated into another system, or some features may be omitted or not performed. Alternatively, the coupling or direct coupling or communication connection shown or discussed with each other may be an indirect coupling or communication connection via some interfaces, devices or units, which may be in electrical, mechanical or other form.
The units described as separate units may or may not be physically separate, and units shown as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.
In addition, each functional unit in each embodiment of the present application may be integrated in one processing unit, or each unit may exist alone physically, or two or more units may be integrated in one unit. The integrated units may be implemented in hardware or in software functional units.
The integrated units, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application may be embodied in essence or a part contributing to the prior art or all or part of the technical solution in the form of a software product stored in a storage medium, including several instructions to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in the embodiments of the present application. And the aforementioned storage medium includes: a U-disk, a removable hard disk, a read-only memory (ROM), a random access memory (RAM, random access memory), a magnetic disk, or an optical disk, or other various media capable of storing program codes.
Claims (10)
1. A power over ethernet method, applied to a switch, the switch powering a terminal through a communication cable, the method comprising:
acquiring the cable length of a communication cable between the switch and the terminal;
determining a voltage drop of the communication cable based on a cable length of the communication cable and a load current of the terminal;
and adjusting the output voltage of the switch for supplying power to the terminal based on the preset working voltage range of the terminal and the voltage drop of the communication cable.
2. The power over ethernet method according to claim 1, wherein said obtaining a cable length of a communication cable to which said switch is connected comprises:
transmitting a first pulse signal to the terminal through the communication cable, and receiving a second pulse signal reflected to the switch by the terminal through the communication cable; the second pulse signal is a pulse signal reflected back to the switch after the first pulse signal reaches the terminal;
the cable length of the communication cable is determined based on a time interval from the switch sending the first pulse signal to receiving the second pulse signal.
3. The power over ethernet method of claim 1, wherein said determining a voltage drop of said communication cable based on a cable length of said communication cable and a load current of said terminal comprises:
determining a cable resistance of the communication cable based on a cable length of the communication cable;
a voltage drop of the communication cable is determined based on a cable resistance of the communication cable and a load current of the terminal.
4. The power over ethernet method of claim 3, wherein said determining a cable resistance of said communication cable based on said cable length comprises:
acquiring a cable cross-sectional area of the communication cable;
a cable resistance of the communication cable is determined based on a cable cross-sectional area of the communication cable and a cable length of the communication cable.
5. The power over ethernet method according to claim 1, wherein said adjusting the output voltage of said switch for powering said terminal based on a preset operating voltage range of said terminal and a voltage drop of said communication cable comprises:
and sending a pulse width modulation signal to a feedback pin end of a power module of the switch based on a preset working voltage range of the terminal and the voltage drop of the communication cable, wherein the pulse width modulation signal is used for controlling the feedback voltage of the feedback pin end of the power module so as to regulate the output voltage of a voltage output end of the power module.
6. The method of claim 5, wherein the sending a pwm signal to a feedback pin of a power module of the switch based on a preset operating voltage range of the terminal and a voltage drop of the communication cable comprises:
selecting any working voltage from a preset working voltage range of the terminal as the working voltage required by the terminal;
and sending a pulse width modulation signal to a feedback pin end of the power module based on the working voltage required by the terminal and the voltage drop of the communication cable.
7. The power over ethernet method as recited in claim 1, further comprising:
detecting whether the terminal is a power receiving end device meeting the power over Ethernet condition based on a preset pulse detection rule;
if so, the switch supplies power to the terminal through the communication cable.
8. A switch, comprising: a power module and a processor;
the voltage output end of the power supply module is connected with a communication cable, the voltage output end of the power supply module is connected with a feedback pin end of the power supply module, the power supply module supplies power to the terminal through the communication cable, and the feedback pin end of the power supply module is used for feeding back the output voltage of the voltage output end of the power supply module;
the processor is connected with the feedback pin end of the power supply module and used for acquiring the cable length of the communication cable between the switch and the terminal; and determining the voltage drop of the communication cable based on the cable length of the communication cable and the load current of the terminal, and sending a pulse width modulation signal to a feedback pin end of the power module based on the preset working voltage range of the terminal and the voltage drop of the communication cable to control the feedback voltage of the feedback pin end of the power module so as to adjust the output voltage of the voltage output end of the power module.
9. The switch of claim 8, further comprising: the voltage dividing module and the filtering module;
the processor is connected with a feedback pin end of the power supply module through the filtering module;
the voltage output end of the power supply module is connected with the feedback pin end of the power supply module through the voltage dividing module.
10. A computer readable storage medium comprising instructions which, when run on a computer, cause the computer to perform the power over ethernet method of any of claims 1 to 7.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202311815882.2A CN117792807A (en) | 2023-12-25 | 2023-12-25 | Power over Ethernet method, switch and storage medium |
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| Application Number | Priority Date | Filing Date | Title |
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| CN202311815882.2A CN117792807A (en) | 2023-12-25 | 2023-12-25 | Power over Ethernet method, switch and storage medium |
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| CN117792807A true CN117792807A (en) | 2024-03-29 |
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| CN202311815882.2A Pending CN117792807A (en) | 2023-12-25 | 2023-12-25 | Power over Ethernet method, switch and storage medium |
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