Abstract: Using a mobile radiotelephone network and a traffic routing and information central as well as a navigation apparatus and a mobile radiotelephone in the vehicle, the user requests a current route in dialogue via a mobile radiotelephone network and a traffic routing and information central. The destination input ensues at any arbitrary location independently of a mobile radiotelephone connection to the central. The navigation apparatus initially calculates the route purely self-sufficiently on the basis of the stored on-board data. With an inquiry to the central, it is not the current position but the presumed position at the time of the anticipated reply to the vehicle that is transmitted, and the data of the route recommendation is forwarded to the vehicle in the form of a sequence of path segments.

Abstract: A method and apparatus for monitoring an alarm system such as a fire alarm system having a plurality of alarms connected to a central station determine the amount of departure of measured alarm values from a rated quiescent value and calculate a fluctuation value therefrom, the fluctuation value then being compared at selected time intervals with a rated limiting value. If the result of the comparison shows that the fluctuation value is less than the rated limiting value, a malfunction signal is displayed.

Abstract: A method and apparatus for increasing the response sensitivity and the interference resistance in an alarm system such as a fire alarm system which cyclically samples a plurality of alarm units in the system for obtaining a series of measured values from each alarm unit, the measured values being utilized to form a quiescent value which is stored in a quiescent value memory. With each sampling cycle a current comparison value is formed from the alarm measured value, the stored quiescent value, and a comparison value from a previous sampling cycle stored in a comparison value memory. The current comparison value is then written in the comparison value memory as the new comparison value. The current comparison value is compared with a rated limiting value, and if the comparison value is greater than or equal to the rated limiting value, a display unit is activated indicating an alarm.

Abstract: A danger alarm system has a plurality of call lines and a plurality of alarm circuits respectively connectible to the call lines and operable to provide signals indicative of environmental conditions about the alarm circuits. A central exchange is connected to the call lines and includes a write-read memory and means connected thereto for inputting the busy condition of each of the lines. A multiplexer is connected between the lines and the memory for sequentially interrogating the memory and the lines. Evaluation circuits are provided and operated upon comparison of the call line signals and the corresponding memory locations.

Abstract: In a process for fault recognition in a vehicle locating system, measuring signals are emitted from a vehicle which is to be located and are in each case received by a plurality of separately arranged receiving stations and forwarded, via lines, to a central station for analysis. The measuring signals received in the individual receiving stations are each supplied to checking devices which establish signal adulterations and analyze the latter to form fault signals. In the central station these fault signals are employed, by way of logic links, for the acquisition of specific disturbance reports.