An electrical field device has a microprocessor-controlled control device, a data memory which is inside the device and is connected to the control device via a first memory controller, and a data interface which is connected to the control device and is intended to connect external devices to the electrical field device. In order to ensure access to the data memory inside such a field device even when the control device or internal power supply device is not in working order, the data interface is connected to the data memory inside the device via a second memory controller. There is also disclosed a method for establishing a data link between a data interface of an electrical field device and a data memory inside the device.