VDO Tachograph in Practice: From Basics to Advanced Functions

What is a VDO tachograph and how does it work?

The name “tachograph” comes from the Greek words “tachos” (speed) and “grapho” (write). This device was designed to record vehicle operation and monitor driver activity.

The VDO tachograph model is one of the most popular devices of this type on the European market, manufactured by the German company VDO - Vereinigte DEUTA - OTA, which is part of the Continental Automotive group.

VDO tachograph - Recorded data: speed, driving time, rest

The VDO tachograph records a series of important parameters related to driver work and vehicle operation as a function of time. First and foremost, it monitors the distance traveled by the vehicle and its instantaneous speed. Equally important is recording driver activity, which includes periods of:

• Driving;
• Other work (e.g., loading, unloading)
• Standby (waiting);
• Rest.

It’s also worth noting that the VDO tachograph collects information about the vehicle’s registration number, driver card insertions, driver activities, and events such as speed violations or manipulation attempts.

Differences between analog tachograph and VDO tachograph

Until 2006, vehicles were equipped with analog tachographs, which recorded data on waxed paper discs (charts). However, due to the ease of falsifying records, the use of digital tachographs became mandatory. Until August 2023, carriers were required to use 1st generation digital tachographs, but from that point on, the mandatory tool is the 2nd generation digital tachograph, which you can read more about in our article: Second Generation Smart Tachograph : Practical guide for carriers 2025

Returning to VDO digital tachographs - these devices record information in internal memory and on chip cards and are the size of a typical car radio. In addition, they are equipped with two card readers, a manual data entry switch, a display, and a printer. The VDO digital tachograph can store data for approximately 12 months.

Legal requirements for vehicles over 3.5 tons

According to EU Regulation 3821/85, which came into force on September 29, 1986, tachographs are mandatory vehicle equipment. The installation requirement applies to:

• Vehicles with a permissible total mass exceeding 3.5 tons;
• Vehicles used to transport more than 9 people including the driver.

Currently, tachograph operation is regulated by EU Regulation 165/2014. From July 1, 2026, the requirement to use tachographs will also be extended to vehicles with a GVW greater than 2.5 tons carrying out international transport of goods, which you can read more about in our article: Tachographs in Buses: New EU Regulations from July 1, 2026

The DTCO 4.1 model is a second-generation smart tachograph that meets the requirements of Implementing Regulation (EU) 2016/799 Annex I C. This modern model introduces features that significantly exceed the capabilities of its predecessors.

Operating the VDO tachograph step by step

Proper operation of the VDO tachograph is the foundation of legal work for every professional driver.

VDO Tachograph - Setting the work mode: driving, rest, availability

The VDO tachograph allows setting four basic activities:

1. Driving;
2. Other work;
3. Availability;
4. Rest.

Some activities are recorded automatically - for example, driving turns on automatically when the vehicle starts moving. The rest must be set manually using the buttons on the device panel.

During breaks or rest periods, the driver must absolutely set the activity to “rest.” Incorrect marking of this time may result in sanctions during inspections, which is why it is so important to systematically ensure the proper setting of the work mode.

VDO Tachograph - Responding to device messages and alerts

During work with the VDO tachograph, various messages and alerts may appear. Most often they concern speeding or violations of working time. Each message displayed on the screen should be confirmed by pressing the OK button twice.

Ignoring alerts can lead to incorrect registration of working time or other data. Proper response to the displayed information is crucial for maintaining compliance with regulations and avoiding potential consequences during inspections.

VDO Tachograph - How does operation work in dual crew mode?

Most VDO tachographs are adapted for dual crew operation and have two card slots. The first driver’s card (currently driving the vehicle) should be in slot 1, while the second driver’s card should be in slot 2. When drivers switch positions at the wheel, it is also necessary to switch cards in the slots.

It is worth emphasizing that when switching cards, you should not mark the end and restart of work - these activities are only performed before starting and after ending daily or weekly rest periods.

Proper card exchange enables verification of the correctness of changes in the persons driving the vehicle, which is particularly important during roadside inspections.

Advanced functions of the VDO 4.1 tachograph

The DTCO 4.1 model represents the second generation of smart tachographs, introducing features that significantly streamline drivers’ work and increase data security in road transport. This device offers solutions that go far beyond the basic functionality of its predecessors.

Automatic registration of border crossings and loading locations

The 2nd generation VDO DTCO 4.1 digital tachograph automatically detects and records the moment a vehicle crosses a border. This means that the driver does not have to stop after crossing the border to manually enter the country symbol. The device also records the precise position and time during loading and unloading operations.

This functionality uses an extended GNSS (Global Navigation Satellite System) module, which works with the European Galileo system (OS-NMA). This system provides the highest level of cryptographic protection, protecting navigation messages from potential cyberattacks.

Remote data download using Bluetooth technology

The DTCO 4.1a tachograph has also been equipped with an integrated Bluetooth module, enabling remote data download using smartphones or other external devices. This feature significantly facilitates regular downloading of vehicle data from the tachograph memory and driver cards.

It is worth emphasizing that according to EU regulations, mandatory data download must take place every 28 days for driver cards and every 90 days for tachograph mass memory. Importantly, in this case, Bluetooth technology eliminates the need for the driver’s physical presence at the transport base, which optimizes operational processes.

Increased data security and protection against manipulation

The DTCO 4.1 tachograph processes drivers’ personal data, which is subject to special protection in accordance with applicable regulations. The entrepreneur, as the data administrator, is obliged to ensure an appropriate level of security and inform employees about the monitoring system.

It is also worth emphasizing that the VDO DTCO 4.1 model has been equipped with advanced mechanisms protecting against manipulation attempts. This is particularly important in the context of growing cyber threats and the need to ensure the integrity of recorded data.

Compliance with the latest EU regulations

The DTCO 4.1 tachograph has been designed in full compliance with EU Regulation 165/2014 and the Mobility Package. These regulations specify precise requirements for the functionality of second-generation smart tachographs.

From August 21, 2023, all newly registered vehicles must be equipped with a second-generation smart tachograph. As of December 31, 2024, this obligation covers all vehicles in international traffic with tachographs from before June 2019.

Calibration, legalization, and and interpretation of data from the VDO tachograph

Proper functioning of the VDO tachograph requires regular service activities and the ability to interpret the recorded data. Knowledge of procedures related to legalization and calibration guarantees measurement accuracy and compliance with applicable regulations.

When to perform a VDO tachograph calibration?

Calibration of the VDO tachograph is the process of confirming or updating vehicle parameters stored in the device’s memory. The first calibration should be carried out within 14 days of the vehicle’s registration date, regardless of whether it is new or used. Subsequent calibrations are performed every 24 months.

However, there are situations requiring earlier calibration:

• Damage to the tachograph or security seals;
• Improper device operation;
• Replacement of tires on the drive axle;
• Change of vehicle registration number.

Reading data from the driver card and VDO tachograph

According to applicable regulations, data from the driver card should be downloaded at least once every 28 days, while from the tachograph every 90 days. The process of reading data from the driver card usually takes 2-5 minutes.

The data download procedure includes the following steps:

1. Inserting the driver card into the slot;
2. Placing the company card in the second slot;
3. Connecting the reader;
4. Starting data download from the tachograph’s mass memory.

Downloaded data must be stored for 12 months from the date of reading.

Interpretation of printouts and pictograms

Printouts of data from the VDO tachograph contain telematic data, including:

1. Print date;
2. Type of printout;
3. Driver data;
4. Vehicle data;
5. Type of tachograph;
6. Date of last calibration;
7. Forms of driver activity.

Individual information is marked with pictograms - unified graphic signs that are identical for all digital tachographs. Knowledge of pictograms allows operation of any tachograph regardless of the language set.

In newer versions of VDO GEN2v2 tachographs, additional pictograms related to loading, unloading, and crossing borders between countries have been introduced. This functionality significantly facilitates data interpretation during roadside inspections.

Practical tips for using the VDO tachograph - summary

The VDO tachograph is an essential tool in the daily work of drivers - its proper operation guarantees compliance with regulations and safety. The DTCO 4.1 model offers a range of advanced features, such as automatic registration of border crossings and remote data download, which significantly streamlines work.

It’s worth remembering obligations such as calibration every 2 years and regular data download - neglecting them can result in high penalties. Mastering the basic and advanced functions of the tachograph is today not only a legal requirement but also a condition for safe and professional transport.

If you run a transport company and need support with issues related to tachographs and drivers' payroll calculation, bookkeeping, or HR and payroll calculation services - contact us, and our team of specialists will be happy to provide support!

VDO Tachographs - Frequently Asked Questions

Below we have collected questions about VDO tachographs that we hear most often and provided answers to them. If there is an issue you’re interested in that is not among them, contact us, and our specialists will be happy to provide support!

What are the main functions of the VDO tachograph?

The VDO tachograph records driver working time, vehicle speed, distance traveled, and rest periods. This device ensures compliance with regulations regarding driver working time and contributes to improving safety in road transport.

How often should the VDO tachograph be calibrated?

The VDO tachograph should be calibrated every 24 months. The first calibration is performed within 14 days of vehicle registration. Additionally, calibration is required after replacing tires on the drive axle, changing the registration number, or in case of device malfunction.

How often should data be downloaded from the tachograph and driver card?

Data from the driver card should be downloaded at least once every 28 days, while data from the tachograph - every 90 days. The downloaded information must be stored for a period of 12 months from the date of reading.

Which vehicles must be equipped with a VDO tachograph?

The VDO tachograph is mandatory in vehicles with a permissible total mass exceeding 3.5 tons and in vehicles used to transport more than 9 people including the driver. From July 1, 2026, this obligation will also include vehicles with a GVW above 2.5 tons carrying out international transport of goods.

What advanced features does the VDO 4.1 tachograph offer?

The VDO 4.1 tachograph automatically registers border crossings and loading/unloading locations, enables remote data download via Bluetooth, provides increased data security and protection against manipulation, and is fully compliant with the latest EU regulations regarding smart tachographs.