A DC-power supply device for supplying operational DC power to a plurality of DC-powered devices via a single twisted-pair wired bus, each DC-powered device operable in an initialization mode requiring a lower DC power amount than in a respective regular operation mode of the DC-powered device, the DC-power supply device comprising: - a power interface for providing, via the single twisted-pair wired bus, DC output power to the plurality of DC-powered devices that are connected in parallel via the wired bus; - a DC-power-supply network communication unit configured to receive via the power interface by means of link layer discovery protocol, LLDP, communication, from the DC-powered devices connected via the wired bus, respective DC-power requirement information indicative of a DC-voltage requirement and a DC-current requirement for operation of the respective DC-powered devices in their respective regular operation mode, wherein the DC-power requirement information comprises preferred voltage with resulting current requirements as well as all compatible voltages with the related maximum current values; and - a DC-power-supply control unit, which is configured: - to drive, operating the DC-power supply device in an initialization supply mode, delivery of a predetermined initialization DC output power amount via the power interface, wherein the initialization DC output power amount is suitable for driving the connected DC-powered devices in their initialization mode that includes transmission of the respective power requirement information for their respective regular operation mode to the DC-power-supply device via the wired bus; - to determine from among a plurality of available DC output power amounts that the DC-power supply device is configured to supply in an operation supply mode, using the DC-power requirement information received from each of the plurality of DC-powered devices and a predetermined power-determination rule, an operational DC output power amount to be output via the output power interface, the operational DC output power amount having an operational DC voltage amount being suitable for powering operation of the plurality of DC-powered devices in their respective regular operation modes; and - to subsequently drive, operating the DC-power supply device in the operation supply mode, distribution of the determined operational DC output power amount to the plurality of DC-powered devices via the power interface, such that the single twisted-pair wired bus is provided with a DC-voltage amount for powering each of the plurality of DC-powered devices. - a power interface for providing, via the single twisted-pair wired bus, DC output power to the plurality of DC-powered devices that are connected in parallel via the wired bus; - a DC-power-supply network communication unit configured to receive via the power interface by means of link layer discovery protocol, LLDP, communication, from the DC-powered devices connected via the wired bus, respective DC-power requirement information indicative of a DC-voltage requirement and a DC-current requirement for operation of the respective DC-powered devices in their respective regular operation mode, wherein the DC-power requirement information comprises preferred voltage with resulting current requirements as well as all compatible voltages with the related maximum current values; and - a DC-power-supply control unit, which is configured: - to drive, operating the DC-power supply device in an initialization supply mode, delivery of a predetermined initialization DC output power amount via the power interface, wherein the initialization DC output power amount is suitable for driving the connected DC-powered devices in their initialization mode that includes transmission of the respective power requirement information for their respective regular operation mode to the DC-power-supply device via the wired bus; - to determine from among a plurality of available DC output power amounts that the DC-power supply device is configured to supply in an operation supply mode, using the DC-power requirement information received from each of the plurality of DC-powered devices and a predetermined power-determination rule, an operational DC output power amount to be output via the output power interface, the operational DC output power amount having an operational DC voltage amount being suitable for powering operation of the plurality of DC-powered devices in their respective regular operation modes; and - to subsequently drive, operating the DC-power supply device in the operation supply mode, distribution of the determined operational DC output power amount to the plurality of DC-powered devices via the power interface, such that the single twisted-pair wired bus is provided with a DC-voltage amount for powering each of the plurality of DC-powered devices.