What .ddd files are and which deadlines apply
If you run trucks or buses with a digital tachograph, you will deal with .ddd files. This page explains where the files come from and which duties the law attaches to them. It is written for operations taking the subject in-house for the first time.
- copy the driver card
- 28 days
- copy the vehicle unit
- 90 days
- keep the files
- 1 year
What is inside a .ddd file
A .ddd file is the unaltered extract from a digital tachograph, holding the recorded activities together with a cryptographic signature. The signature makes it possible to verify later that nothing was changed. The file itself is the authoritative record, and a printed report is only a view of it.
Two sources produce such files. The driver card records what a driver did across all vehicles, and the mass memory of the vehicle unit records what happened to the vehicle, including periods with no card inserted. Each regular readout produces one file, which you keep.
The files are not called .ddd everywhere. In Spain they usually end in .tgd, in France in .c1b or .c1c for driver cards and in .v1b or .v1c for vehicles. Some download devices and programs also write .esm, .add, .dtc or .dtg. The content is the same everywhere, only the ending is different. Scernetta recognises the file by its content and reads all of these endings.
The copying deadlines
The company must copy the data regularly, before the memory is overwritten. In Germany the driver card has to be copied at the latest every 28 days, and the mass memory of the vehicle unit every 90 days. The deadlines are set in the Fahrpersonalverordnung, and letting them slip risks a fine even when the drivers drove without fault.
In day-to-day operation the 28-day deadline is the critical one, because it runs per driver. The analysis page offers a free email reminder for it.
Keeping the files
Copying alone is not enough, the files must be kept for at least a year, in the original and unchanged. A plain archive folder per driver or vehicle is the usual approach, covered by your normal backup. Which file still has to be kept and which has served its term is something the program can show you as well.
You still have to analyse them
Copying and keeping the files does not finish the job, the company also has to review the data for infringements and discuss them with the drivers. That analysis is exactly what Scernetta is built for. The fastest impression is the analysis in the browser, which reads one card locally and shows the finished report.
If you have a .ddd file at hand, have a look at its report. The analysis runs in the browser, and the file never leaves your computer.