Patent ID: 7905394

Claim:
An arrangement comprising a tachograph and having a data store on a data card, wherein the tachograph has an interface which is used for data interchange between the tachograph and the data store, which tachograph has logic functional modules and at least one memory and the logic functional modules are operable to create at the start of the data transmission a virtual map of the data store in the memory of the tachograph wherein the virtual map provides a one-to-one correspondence between data elements in the virtual map and data elements in the data store, to effect subsequently read and write access operations by the logic functional modules on the virtual map in the memory, and to effect a write operation regularly by accessing the data store on the data card, during which the differences between the virtual map and the data store are aligned, wherein the regular read and write access is effected (a) at periodic intervals of time or (b) when a particular volume of data needs to be aligned between the virtual map and the data store on the basis of changes in the map, or both (a) and (b).