Method for operating a data recording system

A method for operating a data recording system having a central station, an intermediate station, and a terminal station, the central station and the intermediate station define a tertiary, two-way communication path, and the intermediate station and the terminal station define a primary, two-way communication path via a radio link, which comprises the steps of:

• creating a message or a message part being valid for a limited time in the central station on a basis of a command using parameters;
• transmitting the message or the message part from the central station to the intermediate station for a data transmission;
• forwarding the message or the message part from the intermediate station to the terminal station if the message or the message part is still valid;
• generating a plurality of message parts which have different validity time limits in the central station on a basis of the command;
• transmitting the plurality of message parts which are valid for a limited time from the central station to the intermediate station;
• checking a validity of the message parts in the intermediate station;
• and
• transmitting a message part concerned within a message from the intermediate station to the terminal station if the message part is still valid for transmission from the intermediate station to the terminal station;
• wherein the time-variable parameter of the message part is accepted as valid by the terminal station if the time-variable parameter of the message part is greater than the time-variable parameter of the terminal station and the time-variable parameter of the message part is less than a sum of a value of the time-variable parameter of the terminal station and an integer value greater than zero.