Abstract: A method for testing and safeguarding the availability of a networked system which is assigned to a system carrier, wherein a multiplicity of subscribers exchange data via a bus-type network which is comprised of one or more bus lines. Specific voltage levels are applied to the bus line or the lines by the appropriate subscribers. By virtue of this, as a minimum, at least individual subscribers transmit data. The bus line or the lines is/are monitored by the at least one receiving subscriber for an overshoot or undershoot of voltage levels. Due to this, the data is evaluated in at least one receiving subscriber with the aid of voltage levels. During operation of the system, signals present on the bus-type network are discriminated, tested or measured with respect to at least one signal criterion by individual subscribers under conditions defined in a network-wide manner for all subscribers.

Abstract: An electronic vehicle controller has a processor unit and a communication output stage for coupling the controller to a databus. A data protocol device, which is connected between the processor unit and the communication output stage, variably defines the data protocol to be used for a particular data transfer, as a function of protocol control information which is supplied to its input side. The data protocol device may be in the form of hardware or software, and allows flexible data protocol selection even at the end of the controller development process.

Abstract: A semiconductor circuit for an electronic unit having at least one microcontroller comprises at least one voltage regulator for providing, from a first supply voltage, at least one second supply voltage for the microcontroller and for circuits of the unit which cooperate with the microcontroller. The circuit further comprises, in monolithic form, a transceiver unit having transmitting and receiving device for coupling a microcontroller to the two-wire bus. This monolithic construction may additionally comprise watchdog functions, various wake-up functions and an interface via which a serial data exchange with the at least one microcontroller is possible. Furthermore, it may have an apparatus for determining, throughout the network, bus subscribers having reference-ground potential faults and for quantifying such faults.

Abstract: A method and apparatus for determining potential shifts between electronic modules in a wire bus network or for determining the correspondence quality of their communications operating levels in the network interconnection. The bus medium comprises at least one wire bus which is directly electrically connected to the electronic modules. An offset voltage is added in at least one bus subscriber (test subscriber) on the transmission side to at least one of two dominant, normal source levels and a test message is transmitted into the bus network by the test subscriber which is in this dominant state onto the bus network. This results in a modification of the source level in a predetermined manner. Depending on whether at least one of the two dominant source levels is decreased or increased by the adjustable offset voltage, an evaluation of whether the (reference-earth) potential-defective bus subscriber loses or gains its reception capability is performed.

Abstract: In a method for testing the ground contact of parts of a networked system in which data are sent and received via at least one line, at least one line at each part is connected via a resistance arrangement to a common potential of the parts and is connectable via a controllable switch to a further potential. The voltage across the resistance arrangement is compared with a predetermined potential when the line is at one potential in a steady state, and the state of the ground contact of the part is deduced from a comparison of the voltage across the resistance arrangement with the predetermined potential.

Abstract: In a data communication system, in particular for a motor vehicle, the transmission lines that lead to the individual terminals are interconnected at a passive network in a star configuration and are there provided with frequency-dependent attenuation means, preferably ferrite beads. Good characteristic impedance adaptation is thus obtained for suppressing high-frequency distributing signals, while retaining free choice of the system parameters for the steady data symbolic state. The system may be enlarged by means of additional star networks into a tree or meshed structure.