Fleet United Kingdom

Tachograph and Fleet solutions for more efficiency




A.T.F - Authorised Testing Facility

DVSA Authorised testing facilty.


Abbreviation for the European Agreement concerning the work of crews of vehicles engaged in international road transport. The AETR is aligned with EU social regulations.

Annex 1B

Technical specification covering digital tachographs. Published as Regulation (EC) No. 1360/2002


Abbreviation of Application, mostly for Smartphones

ATC (Rolling Road Test Computer)

Diagnostic system that can be used in conjunction with a roller dynamometer to test tachographs.

Authorised workshop

Workshop that has been approved to test tachograph systems and EU control units/tachograph systems.

Availability time

Period recorded as working time by tachographs and defined as other time when the worker is present and available.




Mandatory rest period for driving crews.



CAN bus

Technology used for networking various electronic systems with standardised interfaces and protocols via a cable.


See "Driver 2."

Compact Test Computer (CTC)

Diagnostic system for calibrating and testing digital tachographs.

Company card

Smart card identifying the company using/owning the vehicle. The company card protects the data stored on digital tachographs from unauthorised access.


The constant “c” can be set and is required by the tachograph to display speed or rpm correctly. On the DTCO it is adjusted to the vehicle’s distance pulse count with the aid of approved service diagnostic systems.

Control card

Smart card giving authorities and control bodies access to tachograph data stored in the mass memory.

Control Unit

EC control unit




Directives are procedures laid down by legislatory bodies.


Copying a part or all of the data stored in the mass memory of a control unit or in the memory of a smart card. During the download process, none of the stored data is modified or deleted.

Driver 1

Any person who drives a vehicle (driver).

Driver 2

Any person on board who may drive if necessary (co-driver).

Driver card

Personal smart card for drivers of vehicles with digital tachographs on which driving, working and rest times are recorded. 

Driving time

Driving time is the working time a person spends driving a vehicle.


Abbreviation for digital tachograph

DTCO 1381

Digital tachograph from VDO.   



EC control unit

See "EC tachograph." 

EC control unit / tachograph system inspection

Periodic inspection of EC tachograph systems in accordance with legal requirements (at least once every two years).

EC tachograph

Recording equipment approved for use in Europe for recording driving, working and rest times, as well as speed travelled.


Abbreviation for an electronic diesel consumption measurement system that provides the driver with a continuous readout of fuel consumption. On vehicles fitted with EDM the tachograph can be linked up to an additional sensor so fuel consumption can be recorded.

Electronic speedometer

Electronic device that displays speed and distance travelled



FTCO 1319

Abbreviation for “flat tachograph”; additional designation for the 1319.



Hazardous goods vehicle

Vehicle permitted to transport dangerous goods by road. 


Communications protocol for transmitting data via the Internet.



Installation notice

Tamperproof, sealed notice displayed in the vehicle as required by law which contains key information relating to calibration of the tachograph unit.

Instrument cluster

Multifunctional display unit which displays, monitors and manages vehicle functions.




Software from VDO which allows workshops to work on digital tachographs.


Abbreviation for Kienzle Tachograph Sensor. The KITAS enables speed information to be captured and transmitted in a tamperproof way.


K-Line is a standard, asynchronous serial interface used on a DTCO for programming and diagnostics.



Limit Controller

Special device which can recognise and report assignable maximum or minimum values.



Mass memory

Data memory integrated into the control unit. The mass memory stores data for 365 calendar days with average driver activity. Average driver activity involves 256 activity changes per day.


Indicates the distance travelled.

Mounting position

Mounting angle of tachograph in relation to the horizontal. 

MTCO 1324

Diagram chart tachograph in radio slot format. 



Number of revolutions

Here: Indicates how many times the engine crankshaft rotates per minute




See "Milometer." 

Other working time

Time spent by crew working but which is not regarded as driving time or availability time (for example loading and unloading the vehicle). 



Proof of inspection form

Legally recognised form for noting the results of tachograph inspections.   

Pulse sender

A pulse sender converts mechanical revolutions (e.g. vehicle movement) into an electrical signal.



Recording unit

Module on new tachograph systems which records working time for up to two drivers as well as the speed and distance travelled. 


Here: Legislation passed by the EU Council of Ministers concerning the use of tachographs (e.g. EEC Regulation No. 3820/85 and 3821/85).

Rest time

Time that workers employed as driving crew in the road transport sector have to themselves. Compliance with rest times is mandatory.

Revolutions per minute

Revolutions per minute (rpm) refers to the number of revolutions of the vehicle’s engine.

Rolling Road Test Computer (ATC)

Diagnostic system that can be used in conjunction with a roller dynamometer to test tachographs. 

RS 232

Standard serial interface.




Security seal that cannot be removed without visible signs of damage.

Seal stamp

Stamp for “signing” a seal, showing the authorising body, country and test workshop. 


Pulse sender/generator used to provide the speed signal for tachograph units. 

Sender lead

Electrical connection between pulse sender and tachograph


See "Sender." 

Service Diagnostic Systems (SDS)

General term for all systems used for calibrating and testing tachograph units. Abbreviated to “SDS”. The STC, MTC, HTC and CTC are all service diagnostic systems.

Smart card

Plastic card featuring an electronic chip on which user-related data is stored.  

Social regulations

Legal requirements regarding working times in the road transport sectors of EU and AETR countries.

Special equipment

Additional functions built into the tachograph system.


Unit for displaying speed. 




General term for EU control devices and other types of tachograph system. 

Tachograph bracket

Bracket with adjustable angle for holding tachograph during inspection. The angle during inspection must correspond to the mounting angle. 

Tachograph Information System

TIS stands for “Tachograph Information System”. It includes different fleet optimisation, digital tachograph analysis, and data management solutions to help fulfil legal obligations and improve operations.

Tachograph system

Recording unit approved nationally that records values such as speed, distance travelled, driving time and stationary periods, etc. but which does not record the crew’s working time.

Test constant

Fixed constant c = 8000 which must be set on the tachograph when testing on an STC test rig.

Time groups

Personal working time divided up into different activities.

Type notice

Sticker supplying manufacturing information for the tachograph such as manufacturer, type, date of manufacture and number, constant, test and approval symbols.



UTC – Universal Time Co-ordinated

Standard co-ordinated world time. 



Vehicle Identification Number

Unique number stamped onto the vehicle in an accessible location on the chassis or manufacturer’s plate

Vehicle Registration Number

Issued by national registration authorities and displayed on a number plate to the front and rear of a motor vehicle.

Visual inspection

Assessment based on a visual check.



Working time

Road transport worker’s time divided up into working time groups – driving time, availability time, and other working time – in accordance with legal requirements. Tachographs also record break/rest times. 

Workshop card

Smart card identifying a trained employee working in an authorised tachograph workshop. The workshop card enables digital tachographs to be tested and calibrated, as well as allowing data to be downloaded.


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