A field device adapter for HART communication with a field device, having at least: - an adapter housing with a first end and a second end, wherein the first end has at least a first connecting element and a second connecting element for electrically connecting a first two-wire cable, and the second end has a least a third connecting element and a fourth connecting element for electrically connecting a second two-wire cable, wherein the adapter housing also has an adapter chamber between the first and second ends (8, 9); characterized in that - adapter electronics arranged in the adapter chamber are provided, which connect the first connecting element to the third connecting element via a first electrical connecting cable and which connect the second connecting element to the fourth connecting element via a second electrical connecting cable, wherein the adapter electronics also comprise a communication resistor housed in the first connecting cable and a preferably unregulated or not regulated power supply circuit for supplying a supply voltage from a loop current flowing in the first connecting cable, wherein the adapter electronics also have a HART modem configured as a secondary master, which is connected to the first connecting cable via a tapping point, and a circuit for short-circuiting the communication resistor, wherein the adapter electronics are configured to wirelessly receive a second radio signal and control the circuit for short-circuiting the communication resistor using the second radio signal in such a way that at least the communication resistor can be selectively activated or deactivated wirelessly so that, in a bridged state, a first radio signal received by the adapter electronics is converted to a preferably HART-based two-conductor signal and can be modulated to the loop current via the tapping point. - an adapter housing with a first end and a second end, wherein the first end has at least a first connecting element and a second connecting element for electrically connecting a first two-wire cable, and the second end has a least a third connecting element and a fourth connecting element for electrically connecting a second two-wire cable, wherein the adapter housing also has an adapter chamber between the first and second ends (8, 9); characterized in that - adapter electronics arranged in the adapter chamber are provided, which connect the first connecting element to the third connecting element via a first electrical connecting cable and which connect the second connecting element to the fourth connecting element via a second electrical connecting cable, wherein the adapter electronics also comprise a communication resistor housed in the first connecting cable and a preferably unregulated or not regulated power supply circuit for supplying a supply voltage from a loop current flowing in the first connecting cable, wherein the adapter electronics also have a HART modem configured as a secondary master, which is connected to the first connecting cable via a tapping point, and a circuit for short-circuiting the communication resistor, wherein the adapter electronics are configured to wirelessly receive a second radio signal and control the circuit for short-circuiting the communication resistor using the second radio signal in such a way that at least the communication resistor can be selectively activated or deactivated wirelessly so that, in a bridged state, a first radio signal received by the adapter electronics is converted to a preferably HART-based two-conductor signal and can be modulated to the loop current via the tapping point.