Communication device and method for exchanging data

Communication device for exchanging data between cars of a railway vehicle network, comprising: an optical transmitting device (16a) which is attachable to a first carriage (12) of the rail vehicle network, an optical receiving device (18a) which is attachable to a second carriage (14) of the rail vehicle network, said optical receiving device (18a) in the direction of the optical sending apparatus (16a) is directed so that a visual connection between the optical sending apparatus (16a) and the receiving device (18a) is made, wherein the data transmission takes place in the form of a free-space optical transmission, characterized in that a first and a second lens (20a, 20b) on each of the of the carriage (12, 14) side facing away from a joint (19a, 19b) are arranged and a variable in its length tube (22a, 22b) mechanically are connected to each other, wherein the lenses (20a, 20b) around the joints (19a, 19b) are pivotable and through the pipe (22a, 2b) are automatically aligned to each other.