Abstract: The process for serially transmitting information entities over a serial bus between subscribers (ECU1 to ECU4) at a common transmission rate for all subscribers, includes providing the information entities with a start bit (Sta) at a beginning of transmission of each of the information entities; waiting to transmit the information entities on the bus from each subscriber until after a bus monitoring time period (T.sub.U) assigned to each subscriber has elapsed; setting a flag after a subscriber receives one of the information entities; monitoring a logic state of the serial bus during a bus monitoring time period (T.sub.U) at a monitoring rate sufficiently high so that receipt of each information entity is detected during reception of a start bit (Sta); each subscriber determining the state of the flag after expiration of the bus monitoring period (T.sub.

Abstract: The device for monitoring functions of control devices of a motor vehicle includes a single monitoring indicator; monitoring signal devices in each control device which generate a monitoring signal characteristic of their operation; a driver stage for controlling the single monitoring indicator located in a central control device; a device for controlling the monitoring signal devices so that monitoring signals are produced, advantageously one after the other, in response to a switch-on signal; a device for producing the switch-on signal such as an ignition device, and at least one line to which each control device is connected so that, when the monitoring signal is produced, the monitoring signal thus produced is transmitted to the central control device including the driver stage and the driver stage controls the single monitoring indicator according to the monitoring signal so produced.

Abstract: The method of reliably interrogating or retrieving control device data in a plurality of control devices in a vehicle using an external test device includes the steps of storing in a central station or nonvolatile memory in the vehicle information items including the types, operating addresses and number of control devices in the vehicle during assembly or final check of the vehicle; connecting the test device to a diagnostic connection connected by communication lines with the control devices and the central station, the diagnostic connection and the communication lines being provided in the vehicle; retrieving the information items from the central station with the test device via a standardized address to obtain the number, operating address and the type of each of the control devices prior to testing or accessing each control device; and, thereafter, in accordance with the data obtained during the retrieving, accessing individual control devices by either an automatic control or a manual control with the

Abstract: To increase the versatility of a central processing unit (30) controlling an operating apparatus, such as apparatus including an engine, installed in an automotive vehicle, a main read-only memory (ROM, 40) stores not only operating data of the vehicle and/or the engine, but additionally, the organization program of the central processing unit (CPU, 30) in modular, or block form in the ROM (40). An auxiliary ROM (41) preferably an electronically erasable ROM is connectable, via an interconnection bus (80) to the CPU (30) and an initial program stored in the main ROM (40) provides a determination or recognition step to be carried out by the CPU (30) first, to determine if the auxiliary EPROM (41) is present; and, if so, to then address the auxiliary EPROM (41) for control of the program run of the CPU; if not, to take programming operating data directly from the ROM (40).

Abstract: A device is proposed for determining a fuel metering signal for an internal combustion engine comprising a tachometer, a load detector, as well as a storage element and a summing member. The load signal is preferably selected at certain times and then stored temporarily, wherafter the load signal is optionally corrected, multiplied with a time interval, and the sum total of the multiplication results represent a value with respect to the metering signal. Preferably, the signals are processed in a digital fashion, and the load signal is corrected after having been digitized. This is done because for example, in case of a hot-wire air flowmeter, there is no linearity between air flow (air mass flow) and the output signal of the air flowmeter.

Abstract: Omission of a pulse in an otherwise regular pulse sequence, such as may be produced by omission of a tooth of a rotating gear that is used to generate a pulse sequence through a pick-up, is utilized after the manner of a special framing pulse, saving the complications of providing a framing pulse, especially in gasoline engine ignition timing. A counter is started with the beginning of every pulse of the sequence and is operated at a multiple of the sequence frequency. If the frequency varies, the count status when the next pulse arrives will vary slightly and this variation may be caused to change the initial condition for the beginning of each count cycle to keep the repetitive counting generally in step with the varying frequency.

Abstract: An oscillator is connected to a backward counter to set the backward counter to a count number representative of its frequency of oscillation, the backward counter being stepped down by clock pulses recurring at a frequency high with respect to the cycling rate of the oscillator until it reaches a reference value, for example zero. The difference between the reference value and the count state of the counter when a predetermined counting period has elapsed, as determined by the duration of one cycle of the input signal, forms an error signal which is transmitted over a bi-directional counter to an integrator which, in turn, controls the oscillator. The system is particularly applicable for use in connection with vehicle wheel brake anti-lock arrangements, and permits determination of wheel speed by oscillation of the oscillator as well as acceleration and deceleration by sensing the error signal.

Abstract: Clock pulses are multiplied by a ratio less than 1 of which the numerator is controlled by a reversible counter. The multiplier output pulses initiate new countdown cycles of a second counter beginning with the clock pulse following the onset of an input frequency pulse and ending with the clock pulse following the onset of the next input frequency pulse. The state of the count at the end of the cycle determines whether the reversible counter will be left unchanged, advanced, or counted back and hence, whether the multiplier output frequency will be left unchanged, increased or reduced. The initial countdown value of the second counter is provided by a long term store which determines the frequency multiplication ratio. The circuit is usable to multiply a variable input frequency in a vehicle brake anti-lock system.