Data transmission system, particularly in a motor vehicle, and data transmission method

DETAILED DESCRIPTION It is accordingly an object of the invention to provide a data transmission system, particularly, in a motor vehicle, and a data transmission method, that overcomes the hereinafore-mentioned disadvantages of the heretofore-known methods and devices of this general type and that has improved short-circuit resistance.
With the foregoing and other objects in view, there is provided, in accordance with the invention, a data transmission system including a bus having two lines with different nominal potentials applied to the two lines at least during data transmission, at least two data processing units connected to one another through the bus, a controller generating data modulated onto at least one of the nominal potentials as modulation signals, at least one driver for generating the modulation signals to be transmitted, the at least one driver connected to the two lines, and a short-circuit detector device for detecting a short circuit of one of the two lines, the short-circuit detector device applying a nominal potential originally provided for a short-circuited one of the two lines to another one of the two lines not short-circuited dependent upon a detection of a short circuit.
In the invention, the occurrence of a short circuit of one or both bus lines is actively checked and when short circuit currents or voltages occur, corresponding counter measures are initiated.
Preferably, the nominal potentials of the two bus lines are switched over after a short circuit has been detected so that, for example, the line previously carrying positive potential is now at zero potential or low potential and the line previously at zero potential or low potential is switched over to the high potential.
If, for example, the bus line previously at high potential shows a short circuit to ground or a low potential value, the switching over of the bus line potentials can have the effect that essentially the same difference voltage between the bus lines is received at the receiver end and the configuration amplitude modulation percentage can be essentially retained in the data transmission