# US 2020/0401547 A1 · Daisy chain connection system and system control method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2020/0401547 A1 - Document ID: US20200401547A1 - Status: Published application - Kind: A1 - Application number: 16/823,609 - Filed: 2020-03-19 - Published: 2020-12-24 - Earliest claimed: 2019-06-20 - Assignees: Hitachi, Ltd. - Applicants: Hitachi, Ltd. - Inventors: Takumi KAWABE - Web page: https://patentgrep.com/patent/US20200401547A1 ## CPC - G06F 13/4247: {on a daisy chain bus} - 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} - G06F 1/3206: Monitoring of events, devices or parameters that trigger a change in power modality - G06F 1/3221: of disk drive devices - G06F 1/3268: {Power saving in hard disk drive} - G06F 1/329: by task scheduling - Y02D 10/00: Energy efficient computing, e.g. low power processors, power management or thermal management - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - Y02D: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE ## Abstract A system having information equipment connected in a daisy chain, where power supply control of the daisy chain-connected information equipment is performed without having to add a dedicated power supply control device. In a daisy chain connection system, second information equipment comprise a control unit and a power supply unit, and a first information equipment and the control unit of the second information equipment include a communication circuit capable of wired communication, and the first information equipment and the power supply unit of the second information equipment include a wireless circuit capable of wireless communication. When turning OFF a power supply to any one of the second information equipment, the first information equipment requests the power supply unit to stop the power supply by using wireless communication, and the power supply unit performs control for stopping the power supply to the control unit according to the request. ## Claims ### Claim 1 A daisy chain connection system in which a first information equipment controls a plurality of second information equipment wire-connected in a daisy chain, wherein the second information equipment comprises: a control unit which performs information processing control in its own information equipment; and a power supply unit which performs power supply control of feeding externally supplied power to its own information equipment, wherein the first information equipment and the control unit of the second information equipment include a communication circuit capable of wired communication using the wired connection, wherein the first information equipment and the power supply unit of the second information equipment include a wireless circuit capable of mutual wireless communication based on wireless connection, wherein, when turning OFF a power supply to any one of the second information equipment, the first information equipment requests the power supply unit of the second information equipment to stop the power supply by using the wireless communication, and the power supply unit performs control for stopping the power supply to the control unit according to the request. ### Claim 2 (depends on 1) The daisy chain connection system according to claim 1, wherein the control unit of the second information equipment further includes the wireless circuit capable of wireless communication with the first information equipment based on wireless connection. ### Claim 3 (depends on 1) The daisy chain connection system according to claim 1, wherein, when turning ON a power supply to any one of the second information equipment, the first information equipment requests the power supply unit of the second information equipment to start the power supply by using the wireless communication, and the power supply unit performs control for starting the power supply to the control unit according to the request. ### Claim 4 (depends on 1) The daisy chain connection system according to claim 1, wherein, when turning OFF a power supply to any one of the second information equipment, after the power supply unit performs control for stopping the power supply to the control unit, the first information equipment confirms a connection status with the control unit, and determines whether the turning OFF of the power supply to the second information equipment was successful based on a result of the confirmation. ### Claim 5 (depends on 3) The daisy chain connection system according to claim 3, wherein, when turning ON a power supply to any one of the second information equipment, after the power supply unit performs control for starting the power supply to the control unit, the first information equipment confirms a connection status with the control unit, and determines whether the turning ON of the power supply to the second information equipment was successful based on a result of the confirmation. ### Claim 6 A system control method in a daisy chain connection system in which a first information equipment controls a plurality of second information equipment wire-connected in a daisy chain, wherein the second information equipment includes a control unit which performs information processing control in its own information equipment, and a power supply unit which performs power supply control of feeding externally supplied power to its own information equipment, wherein the first information equipment and the control unit of the second information equipment include a communication circuit capable of wired communication using the wired connection, wherein the first information equipment and the power supply unit of the second information equipment include a wireless circuit capable of mutual wireless communication based on wireless connection, wherein, when turning OFF a power supply to any one of the second information equipment, the system control method comprises: a power supply stop request step of the first information equipment requesting the power supply unit of the second information equipment to stop the power supply by using the wireless communication; and a power supply stop implementation step of the power supply unit performing control for stopping the power supply to the control unit according to the request in the power supply stop request step. ### Claim 7 (depends on 6) The system control method according to claim 6, wherein the control unit of the second information equipment further includes the wireless circuit capable of wireless communication with the first information equipment based on wireless connection. ### Claim 8 (depends on 6) The system control method according to claim 6, wherein, when turning ON a power supply to any one of the second information equipment, the system control method comprises: a power supply start request step of the first information equipment requesting the power supply unit of the second information equipment to start the power supply by using the wireless communication; and a power supply start implementation step of the power supply unit performing control for starting the power supply to the control unit according to the request in the power supply start request step. ### Claim 9 (depends on 6) The system control method according to claim 6, wherein, when turning OFF a power supply to any one of the second information equipment, after the power supply unit performs the power supply stop implementation step, the system control method further comprises: a power supply OFF determination step of the first information equipment confirming a connection status with the control unit, and determining whether the turning OFF of the power supply to the second information equipment was successful based on a result of the confirmation. ### Claim 10 (depends on 8) The system control method according to claim 8, wherein, when turning ON a power supply to any one of the second information equipment, after the power supply unit performs control for starting the power supply to the control unit, the system control method further comprises: a power supply ON determination step of the first information equipment confirming a connection status with the control unit, and determining whether the turning ON of the power supply to the second information equipment was successful based on a result of the confirmation.