Frequently asked questions
The questions that come up most often about converting .ddd files, answered from how
the service actually works.
What I can upload
Which cards are supported?
Driver card and vehicle unit are fully supported. The company card is supported on an experimental basis. Workshop cards and control cards are not handled: uploading one returns an error naming the unsupported card type.
Is there a size limit?
Yes, 5 MB. That is generous for a driver card; a full vehicle unit download including detailed speed may exceed it. In that case, download only the blocks you need from the unit, leaving out second-by-second speed.
Does it accept other extensions?
Only .ddd. Files such as .tgd, .v1b, .c1b or
other formats used by fleet software are not accepted. Renaming the extension does not work: the
contents stay as they were and decoding fails.
Do I need to register? Is it free?
No registration, no account, no cost. The service is funded by advertising.
My data
Do files stay on the server?
No. The uploaded file and the generated PDF are deleted immediately after the download. If the download is not completed, an automated routine removes them within an hour.
What if the conversion fails?
The file is kept for a maximum of seven days, in a separate area and renamed with a random code that removes the original filename, so we can work out what went wrong and fix the converter. After seven days it is deleted automatically. The full detail is in the privacy policy.
Does anyone read my data?
Data is not disclosed to third parties and not used for anything other than the conversion. There is no profiling. The only case in which a file may be examined is the one just described: a failed conversion, within the seven days, in order to fix a fault.
When something goes wrong
The conversion fails — why?
The most frequent causes, in order:
- Unsupported card type — workshop or control
- Unrecognised file — not a tachograph download, or altered
- Corrupted file — interrupted download, or opened and re-saved in an editor
- Variant not yet handled — some vehicle unit download formats are not covered
The last case is the only one we can fix, and also the one we cannot discover without your help. If a file you believe is valid will not convert, let us know, giving the date and time of the attempt.
The PDF is missing a section I expected
It may depend on the file type, on the generation of the equipment, on the data never having been recorded, or on that section not being converted yet. All four cases are explained in what is converted.
The file covers a shorter period than I need
Card memory is finite and the oldest data is overwritten. A file downloaded today covers the most recent period, not necessarily the one you are looking for. If you need a past period, the only source is a download made at the time.
The result
Does the PDF have legal value?
No. It is a reading aid. The document that counts is the original .ddd file with its
digital signatures intact — which the converter neither modifies nor verifies. Always keep the
original.
Can I get the data in another format?
Besides the PDF, the service produces a JSON representation of the data internally. If being able to download it for processing with other tools would be useful to you, tell us.
How long does it take?
A few seconds. If it stays in processing for a long time, decoding has probably failed: try again, and if it happens repeatedly let us know.
This page describes how Tacho Converter works. For legal obligations, refer to the official texts.