Adapter for a 2-wire field device, particularly for process and/or automation engineering, wherein the adapter comprises at least - a communication unit for the wireless, particularly bidirectional, communication with an external unit, - an energy storage unit designed to supply electrical energy at least to the communication unit, and a first bidirectional connection element designed to put the adapter into electrical contact with a second connection element of the field device, which is complementary to the first connection element, wherein the at least two connection elements (7a, 7b) are designed for the bidirectional provision of power to the at least one adapter and for the exchange of information, wherein the two connection elements (7a, 7b) are serial interfaces that are complementary to one another, wherein the two connection elements (7a, 7b) are designed to supply electrical energy at least to the adapter and to exchange information separately from one another, wherein the connection elements (7a, 7b) have at least two contact elements (12a, 12b), wherein a first contact element is used to supply energy and at least a second contact element is used to exchange information, characterized in that a computing unit is provided which is designed at least to control the provision of electrical energy to the communication unit via the connection elements (7a, 7b) and/or via the energy storage unit. wherein the adapter comprises at least - a communication unit for the wireless, particularly bidirectional, communication with an external unit, - an energy storage unit designed to supply electrical energy at least to the communication unit, and a first bidirectional connection element designed to put the adapter into electrical contact with a second connection element of the field device, which is complementary to the first connection element, wherein the at least two connection elements (7a, 7b) are designed for the bidirectional provision of power to the at least one adapter and for the exchange of information, - a communication unit for the wireless, particularly bidirectional, communication with an external unit, - an energy storage unit designed to supply electrical energy at least to the communication unit, and a first bidirectional connection element designed to put the adapter into electrical contact with a second connection element of the field device, which is complementary to the first connection element, wherein the at least two connection elements (7a, 7b) are designed for the bidirectional provision of power to the at least one adapter and for the exchange of information, wherein the two connection elements (7a, 7b) are serial interfaces that are complementary to one another, wherein the two connection elements (7a, 7b) are designed to supply electrical energy at least to the adapter and to exchange information separately from one another, wherein the connection elements (7a, 7b) have at least two contact elements (12a, 12b), wherein a first contact element is used to supply energy and at least a second contact element is used to exchange information, characterized in that a computing unit is provided which is designed at least to control the provision of electrical energy to the communication unit via the connection elements (7a, 7b) and/or via the energy storage unit.