Abstract: A method for operating a data network, which includes at least one transmission link, defined by a transmitter and a receiver, wherein in test mode the actual level reserve in the direction of the sensitivity limit, thus between the actual transmitting power of the transmitter and the actual sensitivity limit of the receiver, is determined for at least one transmission link. To better utilize the transmitting capacity of the data network, in test mode, the actual level reserve in the direction of the overload limit, thus between the actual transmitting power of the transmitter and the actual overload limit of the receiver, is also determined for the at least one transmission link.

Abstract: Method for addressing components of a first network, especially in the case of data bus systems in transport vehicles, in which each component is assigned a first address for the mutual communication within the network and the first addresses are stored in a central register, in which at least one particular component of the first network communicates with another network, this component, when dialling into the second network, is assigned a second address by the latter and, within the first network, addressing takes place on the basis of function-specific address components, identical function blocks of the components being addressed via identical function-specific address components.

Abstract: A method for checking a ring optical network line for data transmission between a plurality of network subscribers in a motor vehicle, wherein one network subscribers carries out a master function, wherein, apart from the optical network line, there is a further communication line which has a star structure. The network subscribers having the master function is arranged in the centre of the star structure and is connected directly via the communication line to every other network subscribers. The optical network line is checked by the network subscriber having the master function outputting a start signal to the individual network subscribers. The individual network subscribers acknowledge the start signal for the network subscribers the master function via the communication line. After the start signal, the network subscriber having the master function outputs an initialization signal via the optical network line.

Abstract: A method for operating a data network, which includes at least one transmission link, defined by a transmitter and a receiver, wherein in test mode the actual level reserve in the direction of the sensitivity limit, thus between the actual transmitting power of the transmitter and the actual sensitivity limit of the receiver, is determined for at least one transmission link. To better utilize the transmitting capacity of the data network, in test mode, the actual level reserve in the direction of the overload limit, thus between the actual transmitting power of the transmitter and the actual overload limit of the receiver, is also determined for the at least one transmission link.

Abstract: Method for addressing components of a first network, especially in the case of data bus systems in transport vehicles, in which each component is assigned a first address for the mutual communication within the network and the first addresses are stored in a central register, in which at least one particular component of the first network communicates with another network, this component, when dialling into the second network, is assigned a second address by the latter and, within the first network, addressing takes place on the basis of function-specific address components, identical function blocks of the components being addressed via identical function-specific address components.