Abstract: To provide external access to a specification file stored in at least one memory unit, which is associated with at least one electronic control unit which may be in a vehicle, a computer is connected to a first communication bus in the vehicle. A first module in the computer is adapted to communicate with the at least one electronic control unit over the first communication bus. Provided that a user-unique key is connected to a port of the computer and a software component of this key is set to an active authorization state, the computer is enabled to communicate with the at least one electronic control unit. Thus, the computer may read out the specification file as well as update the specification file.

Abstract: To provide external access to a specification file stored in at least one memory unit, which is associated with at least one electronic control unit which may be in a vehicle, a computer is connected to a first communication bus in the vehicle. A first module in the computer is adapted to communicate with the at least one electronic control unit over the first communication bus. Provided that a user-unique key is connected to a port of the computer and a software component of this key is set to an active authorization state, the computer is enabled to communicate with the at least one electronic control unit. Thus, the computer may read out the specification file as well as update the specification file.

Abstract: An electro-optical device including a chiral nematic liquid crystal disposed between flat plates treated to weakly enforce molecular orientation along one preferred direction parallel to the plates. The plates are spaced by a distance small compared to the pitch of the helix typical in a bulk of the material, or the helix compensated by additives to ensure the equivalent situation. By an externally applied electric field the liquid crystal molecular orientation is rotated in a plane parallel to the plates away from the preferred orientation an angle the sign and size of which depends on the sign and magnitude of the field. The optical axis of the liquid crystal, oriented along the molecular orientation, is thus controlled by the external electric field in such a way as to make a linear light valve or other electro-optical device.