A communication system is provided that includes at least two peripheral devices, wherein each peripheral device has at least one I/O interface and the peripheral devices are connected to each other by at least one data bus and exchange data by means of a communication relationship via the data bus. At least one interface device has a peripheral device interface and has a data bus interface, the interface device being connectable by the peripheral device interface thereof to one of the peripheral devices via an I/O interface thereof, and the interface device being connected by the data bus interface thereof to the data bus, and the communication relationship can be preset in the interface device.