US-12627518-B2 - Powered device for Power over Ethernet, Power over Ethernet system, and operating method thereof

Abstract

A powered device (PD) for Power over Ethernet (PoE), a PoE system, and an operating method for PoE are provided. The powered device includes a first Ethernet transmission port, a second Ethernet transmission port, a power meter, and a controller. The first Ethernet transmission port receives a first power and a first packet from a power sourcing equipment (PSE). The first packet includes a first output voltage value and a first maximum allowable power value. The second Ethernet transmission port provides a second power to a next-level powered device. The power meter measures an input voltage value and an input current value of the powered device. The controller sends a second packet to the next-level powered device via the second Ethernet transmission port. The second packet includes a second output voltage value and a second maximum allowable power value.

Inventors

• Chung-Hsien Huang
• Yueh-O Tseng

Assignees

• ZYXEL NETWORKS CORPORATION

Dates

Publication Date

20260512

Application Date

20240829

Priority Date

20240221

Claims (18)

1. 1 . A powered device for Power over Ethernet, comprising: a first Ethernet transmission port, coupled to a power sourcing equipment and configured to receive a first power and a first packet from the power sourcing equipment, wherein the first packet comprises a first output voltage value and a first maximum allowable power value; a second Ethernet transmission port, coupled to a next-level powered device and configured to provide a second power to the next-level powered device; a power meter, configured to measure a first input voltage value and a first input current value of the powered device; and a controller, configured to send a second packet to the next-level powered device via the second Ethernet transmission port, wherein the second packet comprises a second output voltage value and a second maximum allowable power value.
2. 2 . The powered device according to claim 1 , wherein the controller is further configured to subtract the first input voltage value from the first output voltage value to obtain a voltage difference value, and multiply the voltage difference value by the first input current value to obtain a power loss.
3. 3 . The powered device according to claim 1 , wherein: the controller is further configured to calculate the second maximum allowable power value providable to the next-level powered device and obtain the second output voltage value; and when the second maximum allowable power value is higher than or equal to a first threshold and the second output voltage value is higher than or equal to a second threshold, the controller sends the second packet to the next-level powered device.
4. 4 . The powered device according to claim 3 , wherein when the second maximum allowable power value is lower than the first threshold and/or the second output voltage value is lower than the second threshold, the controller stops sending the second packet.
5. 5 . A Power over Ethernet system, comprising: a power sourcing equipment, comprising: a first Ethernet transmission port; and a first controller, coupled to the first Ethernet transmission port and configured to provide a power and send a first packet via the first Ethernet transmission port, wherein the first packet comprises an output voltage value and a maximum allowable power value; and a powered device, comprising: a second Ethernet transmission port, coupled to the first Ethernet transmission port and configured to receive the power and the first packet; a power meter, configured to measure an input voltage value and an input current value of the powered device; and a second controller, coupled to the second Ethernet transmission port and the power meter, and configured to obtain an allowable power value of the powered device according to the output voltage value, the input voltage value, and the maximum allowable power value.
6. 6 . The Power over Ethernet system according to claim 5 , wherein the second controller is further configured to subtract the input voltage value from the output voltage value to obtain a voltage difference value, and multiply the voltage difference value by the input current value to obtain a power loss.
7. 7 . The power over Ethernet system according to claim 6 , wherein: the second controller is further configured to subtract the power loss from the maximum allowable power value to obtain the allowable power value of the powered device.
8. 8 . The power over Ethernet system according to claim 6 , wherein: the first controller is further configured to calculate a maximum allowable power value providable to the powered device and obtain the output voltage value at the first Ethernet transmission port, and when the maximum allowable power value is higher than or equal to a first threshold and the output voltage value is higher than or equal to a second threshold, the first controller sends the first packet to the powered device.
9. 9 . The Power over Ethernet system according to claim 8 , wherein when the maximum allowable power value is lower than the first threshold and/or the output voltage value is lower than the second threshold, the first controller stops sending the first packet.
10. 10 . An operating method for a Power over Ethernet system, wherein the Power over Ethernet system comprises a power sourcing equipment and a powered device, the operating method comprising: sending, by the power sourcing equipment, a first power and a first packet to the powered device, wherein the first packet comprises a first output voltage value and a first maximum allowable power value; measuring, by the powered device, an input voltage value and an input current value of the powered device; and obtaining, by the powered device, an allowable power value of the powered device according to the first output voltage value, the input voltage value, and the maximum allowable power value.
11. 11 . The operating method according to claim 10 , further comprising: subtracting, by the powered device, the input voltage value from the first output voltage value to obtain a voltage difference value, and multiplying, by the powered device, the voltage difference value by the input current value to obtain a power loss.
12. 12 . The operating method according to claim 10 , wherein sending the first packet by the power sourcing equipment comprises: calculating, by the power sourcing equipment, the first maximum allowable power value providable to the powered device and obtaining the first output voltage value; sending, by the power sourcing equipment, the first packet to the powered device when the first maximum allowable power value is higher than or equal to a first threshold and the first output voltage value is higher than or equal to a second threshold.
13. 13 . The operating method according to claim 12 , further comprising: stop sending, by the power sourcing equipment, the first packet when the first maximum allowable power value is lower than the first threshold and/or the first output voltage value is lower than the second threshold.
14. 14 . The operating method according to claim 10 , wherein the first packet is a multicast packet or a broadcast packet.
15. 15 . The operating method according to claim 10 , wherein the Power over Ethernet system further comprises a next-level powered device, the operating method further comprising: sending, by the powered device, a second power to the next-level powered device; and sending, by the powered device, a second packet to the next-level powered device, wherein the second packet comprises a second output voltage value and a second maximum allowable power value.
16. 16 . The operating method according to claim 15 , wherein sending the second packet by the powered device comprises: calculating, by the powered device, the second maximum allowable power value providable to the next-level powered device and obtaining the second output voltage value; sending, by the powered device, the second packet to the next-level powered device when the second maximum allowable power value is higher than or equal to a third threshold and the second output voltage value is higher than or equal to a fourth threshold.
17. 17 . The operating method according to claim 16 , further comprising: stop sending, by the powered device, the second packet when the second maximum allowable power value is lower than the third threshold and/or the second output voltage value is lower than the fourth threshold.
18. 18 . The operating method according to claim 15 , wherein the second packet is a multicast packet or a broadcast packet.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application claims the priority benefit of Taiwan application serial no. 113106063, filed on Feb. 21, 2024. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification. BACKGROUND Technical Field The disclosure relates to a powered device, a power supply network system, and an operating method for the power supply network, and in particular to a powered device for Power over Ethernet, a Power over Ethernet system, and an operating method for Power over Ethernet. Description of Related Art Generally speaking, in a Power over Ethernet (PoE) system, a power sourcing equipment (PSE) may communicate with a powered device (PD) based on a protocol defined in Power over Ethernet standard (for example, IEEE standard 802.3af/at/bt) to determine a power consumption value provided to the powered device, and provide power to the powered device according to the power consumption value. However, in the case where the number of powered devices increases or the Power over Ethernet system has a larger power demand, the power consumption of a cable between the power sourcing equipment and the powered device is more significant. There will be a difference between the power consumption value determined by the above-mentioned protocol and the actual power consumption value. Therefore, the power consumption value determined by the protocol may not be accurate, causing that the power provided by the Power over Ethernet system is not fully utilized. SUMMARY The disclosure provides a powered device for Power over Ethernet, a Power over Ethernet system, and an operating method for Power over Ethernet. The powered device, the Power over Ethernet system, and the operating method can obtain accurate power consumption. A powered device of the disclosure includes a first Ethernet transmission port, a second Ethernet transmission port, a power meter, and a controller. The first Ethernet transmission port is coupled to a power sourcing equipment. The first Ethernet transmission port receives a first power and a first packet from the power sourcing equipment. The first packet includes a first output voltage value and a first maximum allowable power value. The second Ethernet transmission port is coupled to a next-level powered device. The second Ethernet transmission port provides a second power to the next-level powered device. The power meter measures an input voltage value and an input current value of the powered device. The controller sends a second packet to the next-level powered device via the second Ethernet transmission port. The second packet includes a second output voltage value and a second maximum allowable power value. A Power over Ethernet system of the disclosure includes a power sourcing equipment and a powered device. The power sourcing equipment includes a first Ethernet transmission port and a first controller. The first controller is coupled to the first Ethernet transmission port and provides a power and sends a first packet via the first Ethernet transmission port. The first packet includes an output voltage value and a maximum allowable power value. The powered device includes a second Ethernet transmission port, a power meter, and a second controller. The second Ethernet transmission port is coupled to the first Ethernet transmission port. The second Ethernet transmission port receives the power and the first packet. The power meter measures an input voltage value and an input current value of the powered device. The second controller is coupled to the second Ethernet transmission port and the power meter. The second controller obtains an allowable power value of the powered device according to the output voltage value, the input voltage value, and the maximum allowable power value. An operating method of the disclosure is used for a Power over Ethernet system. The Power over Ethernet system includes a power sourcing equipment and a powered device. The operating method comprises the following steps: a first power and a first packet are sent to the powered device by the power sourcing equipment, wherein the first packet includes a first output voltage value and a first maximum allowable power value; an input voltage value and an input current value of the powered device are measured by the powered device and an allowable power value of the powered device is obtained by the powered device according to the output voltage value, the input voltage value, and the maximum allowable power value. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a Power over Ethernet system according to an embodiment of the disclosure. FIG. 2 is a schematic diagram of a Power over Ethernet system according to an embodiment of the disclosure. FIG. 3 is a schematic diagram of a Power over Ethernet system according to an embodiment of the disclosure. FIG. 4 is a flowchart of an operating method according to a