# US 10,313,139 B2 · Power over data lines system with redundant power connections > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,313,139 B2 - Document ID: US10313139B2 - Status: Granted - Kind: B2 - Application number: 15/479,187 - Filed: 2017-04-04 - Published: 2017-10-26 - Granted: 2019-06-04 - Earliest claimed: 2016-04-20 - Assignees: Linear Technology Corporation - Applicants: Linear Technology Corporation - Inventors: David M. Dwelley; Andrew J. Gardner - Web page: https://patentgrep.com/patent/US10313139B2 ## CPC - H04L 12/10: Current supply arrangements - G06F 1/266: {Arrangements to supply power to external peripherals either directly from the computer or under computer control, e.g. supply of power through the communication port, computer controlled power-strips} - H04B 3/44: Arrangements for feeding power to a repeater along the transmission line - H04L 12/40045: {Details regarding the feeding of energy to the node from the bus} - H04L 12/403: with centralised control, e.g. polling - H04L 12/437: Ring fault isolation or reconfiguration {(for SDH/SONET ring networks H04J3/085)} - H04L 12/44: Star or tree networks - H04L 41/0654: using network fault recovery (ring fault isolation or reconfiguration in loop networks without recovery actions by a network management system H04L12/437) - H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M) - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - H04B: TRANSMISSION ## Abstract In one embodiment, a master device has a first port and a second port and initially applies a DC voltage only to the first port. A plurality of slave devices, each have a third port and a fourth port, are serially connected to the master device in a ring, via conductors, starting at the first port and ending at the second port. The conductors simultaneously carry the DC voltage and differential data. Each slave device, after performing a detection routine, then sequentially applies the DC voltage to the adjacent downstream slave device in a first direction around the ring. If the master does not detect the presence of the DC voltage at its second port, the master device applies the DC voltage to both the first port and the second port to sequentially power up the slave devices in both directions around the ring of slave devices. ## Claims ### Claim 1 A powered data communications system comprising: a master device having a first port and a second port, the master device being configured to apply a DC voltage from a voltage source to the first port; a plurality of slave devices, each slave device having a third port and a fourth port; conductors serially connecting the slave devices, via their third port and fourth port, to the master device in a ring between the first port and the second port of the master device, wherein a first end slave device is coupled to the first port of the master device, and a second end slave device is coupled to the second port of the master device, the conductors being configured to simultaneously carry the DC voltage and data; the plurality of slave devices being configured to be sequentially powered up, starting with the first end slave device and ending with the second end slave device, by sequentially applying the DC voltage to an adjacent downstream slave device in a first direction around the ring by closing switches in the slave devices; the slave devices and the master device being configured to perform a detection routine on the adjacent downstream slave device prior to applying the DC voltage to the adjacent downstream slave device; and wherein the master device is configured to detect whether the DC voltage has been sequentially applied to all the slave devices by detecting a presence of the DC voltage at the second port of the master device and, if the master does not detect the presence of the DC voltage at the second port, the master device is configured to apply the DC voltage to both the first port and the second port to sequentially power up the slave devices in both the first direction and a second direction around the ring of the slave devices. ### Claim 2 (depends on 1) The system of claim 1 wherein the slave devices are configured to perform the detection routine by detecting a presence of a signature impedance in the adjacent downstream slave device and then applying the DC voltage to the adjacent downstream device. ### Claim 3 (depends on 1) The system of claim 1 wherein the master device comprises a first switch coupled to the first port for connecting the DC voltage to the conductors coupled to the first port, and comprises a second switch coupled to the second port for connecting the DC voltage to the conductors coupled to the second port. ### Claim 4 (depends on 3) The system of claim 3 wherein the master device comprises a master controller configured to control opening and closing of the first switch and the second switch to apply the DC voltage to the first port and second port, respectively. ### Claim 5 (depends on 3) The system of claim 3 wherein the slave devices comprise a third switch coupled to the third port for coupling the DC voltage to the associated slave device to power up the associated slave device, wherein the slave devices further comprise a fourth switch coupled to the fourth port for coupling the DC voltage to the conductors for powering up a downstream slave device. ### Claim 6 (depends on 5) The system of claim 5 wherein the slave devices comprise a slave controller configured to control opening and closing of the third switch and fourth switch to conduct the DC voltage to and from the associated slave device. ### Claim 7 (depends on 1) The system of claim 1 wherein the DC voltage is coupled to the conductors via inductors. ### Claim 8 (depends on 1) The system of claim 1 wherein each of the slave devices comprises a physical layer device (PHY) for receiving differential data on the conductors via AC coupling components. ### Claim 9 (depends on 1) The system of claim 1 wherein the conductors comprise a twisted wire pair that carry both the DC voltage and differential data. ### Claim 10 (depends on 1) The system of claim 1 wherein the system is a Power over Data Lines (PoDL) system. ### Claim 11 (depends on 1) The system of claim 1 wherein the system is a Power over Ethernet (PoE) system. ### Claim 12 A method performed by a powered data communications system comprising: providing a DC voltage, by a master device, to a first port of the master device, the master device also having a second port; wherein a plurality of slave devices, each slave device having a third port and a fourth port, are connected serially between the first port and the second port in a ring via conductors configured to simultaneously carry the DC voltage and data, wherein a first end slave device is coupled to the first port of the master device, and a second end slave device is coupled to the second port of the master device; sequentially powering up the plurality of slave devices, starting with the first end slave device and ending with the second end slave device, by sequentially applying the DC voltage to the adjacent downstream slave device in a first direction around the ring by closing switches in the slave devices; performing a detection routine on the adjacent downstream slave device prior to applying the DC voltage to the adjacent downstream slave device in the first direction around the ring; detecting, by the master device, whether the DC voltage has been sequentially applied to all the slave devices by detecting a presence of the DC voltage at the second port of the master device; and if the master does not detect the presence of the DC voltage at the second port, applying, by the master device, the DC voltage to both the first port and the second port to sequentially power up the slave devices in both the first direction and a second direction around the ring of the slave devices. ### Claim 13 A powered data communications system comprising: a first master device having a first port, the first master device being configured to provide a DC voltage and apply the DC voltage to the first port; a second master device having a second port, the second master device being configured to provide the DC voltage and apply the DC voltage to the second port; a plurality of slave devices connected serially between the first master device and the second master device, each slave device having a third port and a fourth port; conductors serially connecting the slave devices, via their third port and fourth port, between the first port of the first master device and the second port of the second master device, wherein a first end slave device is coupled to the first port of the first master device, and a second end slave device is coupled to the second port of the second master device, the conductors being configured to simultaneously carry the DC voltage and data; the plurality of slave devices being configured to be sequentially powered up, starting with the first end slave device and ending with the second end slave device, by sequentially applying the DC voltage to an adjacent downstream slave device in a first direction by closing switches in the slave devices; and wherein the second master device is configured to detect whether the DC voltage has been sequentially applied to all the slave devices by detecting a presence of the DC voltage at the second port of the second master device and, if the second master does not detect the presence of the DC voltage at the second port, the second master device is configured to apply the DC voltage to the second port to sequentially power up the slave devices in a second direction. ### Claim 14 (depends on 13) The system of claim 13 wherein the slave devices and the first master device are configured to perform a detection routine on an adjacent downstream slave device prior to applying the DC voltage to the adjacent downstream slave device. ### Claim 15 (depends on 13) The system of claim 13 wherein the first master device comprises a first switch coupled to the first port for connecting the DC voltage to the conductors coupled to the first port, and the second master device comprises a second switch coupled to the second port for connecting the DC voltage to the conductors coupled to the second port. ### Claim 16 (depends on 15) The system of claim 15 wherein the first master device comprises a first master controller configured to control opening and closing of the first switch to apply the DC voltage to the first port, and wherein the second master device comprises a second master controller configured to control opening and closing of the second switch to apply the DC voltage to the second port. ### Claim 17 (depends on 16) The system of claim 16 wherein the slave devices comprise a third switch coupled to the third port for coupling the DC voltage to the associated slave device to power up the associated slave device, wherein the slave devices further comprise a fourth switch coupled to the fourth port for coupling the DC voltage to the conductors for powering up a downstream slave device. ### Claim 18 (depends on 17) The system of claim 17 wherein the slave devices comprise a slave controller configured to control opening and closing of the third switch and fourth switch to conduct the DC voltage to and from the associated slave device. ### Claim 19 A master device for use in a powered data communications system, the powered data communication system including a plurality of slave devices connected in a ring with master device, the master device having a first port and a second port, the plurality of slave devices, each having a third port and a fourth port, for being connected serially between the first port and the second port in the ring via conductors configured to simultaneously carry a DC voltage and data, wherein a first end slave device is for being coupled to the first port of the master device, and a second end slave device is for being coupled to the second port of the master device, the master device comprising: a DC voltage source for supplying a DC voltage to the first port of the master device; the master device comprising a first switch for supplying the DC voltage to the first end slave device, wherein the slave devices sequentially apply the DC voltage to an adjacent downstream slave device in a first direction around the ring; the master device comprising a detector for detecting whether the DC voltage has been sequentially applied to all the slave devices by detecting a presence of the DC voltage at the second port of the master device; and a second switch in the master device controlled so that, if the master does not detect the presence of the DC voltage at the second port, the master device applies the DC voltage to both the first port and the second port to sequentially power up the slave devices in both the first direction and a second direction around the ring of the slave device; the master device comprising low power detection circuitry in the master device for determining if the first end slave device of the second end slave device is compatible for receiving the DC voltage. ### Claim 20 (depends on 19) The master device of claim 19 wherein the master device is configured to apply the DC voltage to the second port if the detector does not detect the presence of the DC voltage at the second port within a prescribed time.