Robot-compatible medium coupling

The invention relates to a medium coupling having a fixed part (1) and a loose part (2). The loose part (2) can, by movement in a joining direction (z) toward the fixed part (1), be brought from a disconnected position into a joined position and by an opposite movement back into the disconnected position. In the disconnected position, the loose part (2) disconnected from the fixed part (1), in thejoined position it is connected to the fixed part (1). The fixed part (1) and the loose part (2) have main positioning aids (4, 5), which interact with each other, on their sides facing each other inthe joined position, which aids position the loose part (2) transversely to the joining direction (z) relative to the fixed part (1) on transition into the joined position. The fixed part (1) and theloose part (2) each have precisely three bearing surfaces (6, 7), which each form a triangle and are arranged so as not to be movable on the fixed part (1) and the loose part (2) at least in the joining direction (z). In at le