The invention comprises a wireless adapter (DA), comprising an energy conversion unit (EE), a HART modem (HM) and a communication unit (KE), the wireless adapter (DA) being connected to a HART communication loop (KS), the energy conversion unit (EE) being designed to obtain the electrical energy required for the operation of the wireless adapter (DA) from HART telegrams transferred via the HART communication loop (KS), the communication module being designed to wirelessly communicate with a mobile operating unit (BE), and the HART modem (HM) being designed to communicate with an automation field device (FG1), which is connected to the HART communication loop (KS).
