A base-unit for non-galvanic coupling to a contactless-unit, the base-unit comprising: an antenna coupled to an RF power source, at least one data-link (12, 22), an authentication controller coupled to the at least one data-link, a data interface for coupling at least one of a data source and data sink to the base unit, the data interface being coupled to the at least one data-link, and a mechanical connector for coupling to the contactless unit, and wherein the base-unit is operable to: transmit and/or receive payload data via the data interface, wirelessly transmit RF power from the RF power source to the contactless-unit in physical proximity to the base-unit, transmit and/or receive authentication data via the at least one data-link to authenticate a non-galvanic connection to the contactless-unit only when the contactless-unit is in physical proximity to the base-unit, transmit and/or receive payload data via the at least one data link following the authentication of the non-galvanic connection to the contactless unit and wherein in operation the relative position of the base-unit and the contactless unit non-galvanically coupled to the base unit is fixed, and wherein the authentication controller further comprises a watchdog timer and the base-unit is further operable to periodically re-authenticate the non galvanic connection to the contactless-unit, the re-authentication period being determined by the watchdog timer, and to disable further payload data transmission and/or reception if the re-authentication of the non-galvanic connection fails. an antenna coupled to an RF power source, at least one data-link (12, 22), an authentication controller coupled to the at least one data-link, a data interface for coupling at least one of a data source and data sink to the base unit, the data interface being coupled to the at least one data-link, and a mechanical connector for coupling to the contactless unit, and wherein the base-unit is operable to: transmit and/or receive payload data via the data interface, wirelessly transmit RF power from the RF power source to the contactless-unit in physical proximity to the base-unit, transmit and/or receive authentication data via the at least one data-link to authenticate a non-galvanic connection to the contactless-unit only when the contactless-unit is in physical proximity to the base-unit, transmit and/or receive payload data via the data interface, wirelessly transmit RF power from the RF power source to the contactless-unit in physical proximity to the base-unit, transmit and/or receive authentication data via the at least one data-link to authenticate a non-galvanic connection to the contactless-unit only when the contactless-unit is in physical proximity to the base-unit, transmit and/or receive payload data via the at least one data link following the authentication of the non-galvanic connection to the contactless unit and wherein in operation the relative position of the base-unit and the contactless unit non-galvanically coupled to the base unit is fixed, and wherein the authentication controller further comprises a watchdog timer and the base-unit is further operable to periodically re-authenticate the non galvanic connection to the contactless-unit, the re-authentication period being determined by the watchdog timer, and to disable further payload data transmission and/or reception if the re-authentication of the non-galvanic connection fails.