Abstract: A method for operating a volatile memory supplied with a supply signal arranged either as a first supply signal of a first supply signal source or a second supply signal of a second supply signal source. If an available first supply signal is present it is used otherwise the second supply signal is used. The supply signal is supplied, based on a switch position of a switching element to the volatile memory. During a detected interrupted first supply signal, the switch position of the switching element is for a predetermined period of time such that the supply signal is supplied to the volatile memory. After expiry of the predetermined period of time, the switch position of the switching element is predetermined such that the volatile memory is decoupled electrically from the supply signal.

Abstract: An assembly has a tachograph and a data memory, in particular a data memory of a data card. The tachograph has an interface designed to exchange data between the tachograph and the data memory, logic function modules and at least one memory. In a method for operating the tachograph, as a result of high security requirements, the data transfer between the data memory and the tachograph is extremely time-intensive. At the start of the data transfer a virtual reproduction of the data memory is created in the memory of the tachograph and the logic function modules first have read and write access to the virtual reproduction in the memory. Data is then regularly written to the data memory of the data card by a write access to the memory, thus eliminating the differences between the virtual reproduction and the data memory.

Abstract: A method for operating a volatile memory supplied with a supply signal arranged either as a first supply signal of a first supply signal source or a second supply signal of a second supply signal source. If an available first supply signal is present it is used otherwise the second supply signal is used. The supply signal is supplied, based on a switch position of a switching element to the volatile memory. During a detected interrupted first supply signal, the switch position of the switching element is for a predetermined period of time such that the supply signal is supplied to the volatile memory. After expiry of the predetermined period of time, the switch position of the switching element is predetermined such that the volatile memory is decoupled electrically from the supply signal.

Abstract: User data is stored in at least one record in at least one predefined, logic data storage area. One respective record ID is assigned to the at least one record. The record ID includes a uniqueness stamp that is unique in the respective predefined data storage area, a unique ID of the predefined data storage area in which the respective record is stored, and a logic position of the respective record within the respective predefined data storage area. A record test value is determined and stored for the user data and the respective associated record ID of the respective record. Data storage area information containing the ID of the respective predefined data storage area and data on at least one value range of the uniqueness stamps of the records currently stored in the respective predefined data storage area is assigned to the respective predefined data storage area.

Abstract: An assembly has a tachograph and a data memory, in particular a data memory of a data card. The tachograph has an interface designed to exchange data between the tachograph and the data memory, logic function modules and at least one memory. In a method for operating the tachograph, as a result of high security requirements, the data transfer between the data memory and the tachograph is extremely time-intensive. At the start of the data transfer a virtual reproduction of the data memory is created in the memory of the tachograph and the logic function modules first have read and write access to the virtual reproduction in the memory. Data is then regularly written to the data memory of the data card by a write access to the memory, thus eliminating the differences between the virtual reproduction and the data memory.

Abstract: An arrangement (1) has a recording device, in particular a tachograph (2) for a motor vehicle, a voltage source (3) supplying power to the recording device and a sensor (S) transmitting a signal thereto, wherein different modules (7, 8, 9, MEM) of the recording device consume energy and are embodied in such away that they are connectable and disconnectable. In order to solve, in particular, a problem of a relatively unstable voltage supply, the aim of the invention is to design a system whose operation is low-affected by the voltage oscillations and interruptions and which is not overcharged by a just unstable energy supply. For this purpose, several (7, 8, 9, MEM) modules are disconnectable or connectable when the energy supply operating voltage (U) is modified.

Abstract: In a method for calculating a cumulative interruption of a driving period, associated with the identity (10) of a vehicle driver, the cumulative interruption of a driving period (?ti) of a determined driver is calculated as the respective accumulated duration of driving period interruptions (ti2, ti4 , ti5). The frequent process is very costly and time-intensive, especially if, for example, it is initiated by the insertion of a card data carrier into a new generation digital tachograph. In order to reduce the calculating time, a temporal reference mark (tRef) to be continuously updated is inserted into the previous records and the accumulated driving period interruption (?ti) is calculated from said mark, in a positive chronological sequence, according to EG-VO No. 1360/2002.