The invention relates to an assembly comprising a main device and an accessory, which can be connected by a safe connector and a safe detection method. According to the invention, the assembly comprises: —a main device (2), —an accessory (3) connectable to the main device (2), —the accessory (3) comprising an accessory connector (4) for mating with a device connector (5) of the main device (2), —the accessory connector (4) and the device connector (5) each comprising one or more supply contacts (7) for transmitting electric power from the main device (2) to the accessory (3), —the main device (2) comprising a detection device (9), which, if connecting the accessory (3) to the main device (2), receives complex accessory data stored by the accessory (3) and which by positive evaluation of the complex data enables applying a supply voltage at the one or more supply contacts (7) of the device connector (5).