DEVICE HAVING A COMMUNICATION APPARATUS FOR DATA TRANSFER VIA A DATA-TRANSFER BUS, AND DATA-TRANSFER SYSTEM HAVING DEVICES OF THIS KIND

The invention relates to a device (1) having a communication apparatus (10) and having a connecting apparatus (20) for connecting the device (1) to a data-transfer bus (2), wherein the connecting apparatus (20) comprises electrical contacts (K1-K5) which can be connected in pairs to corresponding bus-side electrical contacts (K1'-K5') of a bus-side connecting apparatus (20') provided on the bus (2) in order to connect the device (1) to the bus (2), and wherein the electrical contacts (K1-K5) comprise at least one data contact (K1, K2) for transferring a data signal (CANL, CANH), a first supply contact (K3) for transferring a first supply potential (GND), and a second supply contact (K4) for transferring a second supply potential (VS) which differs from the first supply potential. The aim of the invention is to enable simple and reliable address allocation for a plurality of devices (1) connected to the data-transfer bus (2). This aim is achieved in that: the electrical contacts (K1-K5) also comprise an additional contact (K5); the device (1) has a voltage meter (30) in order to measure a potential (POT) across the additional contact (K5, K5'); and the communication apparatus (10) allocates an address to the device (1), which address is selected from a plurality of different specified addresses according to the potential (POT) measured across the additional contact (K5). The invention also relates to a corresponding data-transfer system comprising devices (1) of this kind.