The adaptor device has a plug connector for connecting the adaptor device with a secure digital (SD) card slot of a data acquisition device, where
the SD card slot receives a miniaturized SD card e.g. micro SD card and mini SD card. A controller controls active reading and/or writing access of a Bluetoothcommunication module on a memory of the SD card inserted into the SD card slot and transmission of read/to be written data to the communication module. A button cell holder receives a button cell or a battery in the form of the button cell. An independent claim is also included for a method for transmitting data from a data acquisition device to an external data processing device over an adaptor device.