An apparatus for controlling appliances aboard a vehicle, including a first data processing device having a network interface that can have a vehicle network for bidirectional data transmission between the first data processing device and connected network appliances. Also provided are an input/output device, a graphics processor device connected to the screen thereof and to the first data processing device, a user interface module provided in the first data processing device and that implements a graphical user interface having pages, and at least one separate second data processing device connected to the first data processing device via a separate bidirectional data link and having a network interface for connection to a vehicle network. Via each bidirectional data link it is exclusively possible to transmit predefined data records having data of predefined data types for display on pages from the second data processing device to the first data processing device.