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Tachograph glossary

What is a tachograph?

A tachograph is a recording device fitted to vehicles covered by the applicable rules. It records driver activities and vehicle data used to document driving time, breaks and rest. Zenit can manage available data in the Fleet Management Platform, but does not replace the approved device or the operator's responsibilities.

  • Two sourcesThe driver card and vehicle unit produce separate records.
  • Separate rolesThe tachograph records; the platform organizes the process.
Data and components

What is the difference between a driver card, company card and vehicle unit?

The three components have different roles and should not be treated as interchangeable files.

Driver card

It links recorded activities to a person and follows the driver when they change vehicles. Its download does not replace the vehicle-unit download.

Vehicle unit

It records data related to the vehicle and activities captured on board. Its download does not replace the cards used by drivers.

Company card

It enables the operator to use the functions provided by the tachograph system. In a remote-download workflow it forms part of the configured authorization chain; custody and renewal need clear ownership.

DDD files

DDD is a common name for files downloaded from a tachograph. A reliable archive links every file to its source, period and outcome instead of checking the filename alone.

Download and control

How often must tachograph data be downloaded?

Regulation (EU) No 581/2010 sets maximum periods of 28 days for the driver card and 90 days for the vehicle unit, counting days with recorded activity.

EU maximum periods

Maximum periods for downloading relevant tachograph data
SourceMaximum periodOperational check
Driver card28 daysCheck every card and day with activity
Vehicle unit90 daysCheck every covered vehicle and period continuity

Download is not the final control

After transfer, the operator should check the outcome, integrity, covered interval, errors and missing periods. Operating frequency, retention and exception handling must reflect the legal framework applicable to the operation.

Sources

Primary regulatory sources

Last reviewed: 24 August 2026. This entry explains terminology and process; it does not replace legal assessment of a specific operation.

Tachographs in road transport

Regulation (EU) No 165/2014 covers the construction, installation, use and control of tachographs and defines responsibilities for operators and drivers.

Maximum download periods

Regulation (EU) No 581/2010 sets 28 days for the driver card and 90 days for the vehicle unit.

FAQ

Questions about tachographs and DDD data

Concise answers about data, remote download and the platform's role.

Which data does a digital tachograph record?

It records driver activities and vehicle-related information, including driving, other work, availability, breaks and rest as determined by the device and applicable rules. The driver card and vehicle unit are separate data sources.

What is remote tachograph download?

It transfers driver-card and vehicle-unit data to an archive without necessarily waiting for the vehicle to return. It requires compatible tachograph, device, connectivity and authorization; it does not remove the operator's checks.

Does Zenit replace the tachograph?

No. Zenit organizes downloads, outcomes, deadlines and available data in the fleet management platform; the approved tachograph remains the recording source and the operator retains its responsibilities.