Introduction to Digital Tachographs
- What is it all about? - A Quick History lesson
- Why change?
- When will this happen?
- What is a digital tachograph?
What is it all about? - A Quick History lesson
Tachographs, or as the legislation calls them ‘recording equipment’, have been in use under the current European Union (EU) legislation (EU regulation 3821/85) for 16 years. The technical specification of the current tachograph is contained within Annex 1 of this regulation.
Over this time the tachograph has evolved. In the early days we had mechanical tachographs, which progressed to the early electronic units, but these were subject to interference by unscrupulous users. In order to combat this interference some amendments were made to the regulations that required diagnostic features to be incorporated into the tachograph, and for the signal cables to be armoured to prevent tampering. This takes us the modern electronic heads, for example VDO Siemens 1318, 1319, Stoneridge 8400 and the Motometer that we all know and love.
All of these analogue units record the driver’s periods of duty on a waxed paper disc - a tachograph chart. These are not always interchangeable between the different units and are vulnerable to damage and tampering.
We then had a new concept in design with the modular units - VDO’s 1420 and Stoneridge’s 2400. These still use charts, but have a remote speedometer fitted, allowing variable location of the main unit. The sender unit signal is also encrypted, increasing security, reducing the need for some of the sealing requirements.
Note: EU regulation 3820/85, on driver's hours determines a driver’s periods of driving, other work, breaks and rest, and how those periods of time are to be recorded by use of the different modes. At this time this remains unchanged.
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Why change?
The EU wanted to take advantage of technology now available in order to ensure the security of the recording of the driver’s duty periods. The aim is that the new system is less vulnerable to illegal acts by users to distort the data. The new system will also allow for easier and better control of driver's hours by operators and the enforcement authorities.
This will ensure that the original objectives of:
- Road safety
- Social legislation
- Providing a more even commercial playing field between operators are supported in a robust fashion.
These new generations of tachographs are also designed to allow operators to utilise the technology to enable low cost expansion to support other functions for fleet management.
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When will this happen?
In a nut shell ALL new vehicles that require fitment of a tachograph (current exemptions still apply) first registered on and after 5th August 2004 should have been fitted with a digital unit complying to Annex 1B . An extension to this date of 1 year was agreed by the Commission because of technical difficulties experienced by the tachograph manufacturers and these are still being experienced for some vehicles. In March of 2005 the Minister, David Jamieson, released a statement confirming that GB would support the introduction and use of digital tachographs from August this year, but would not require mandatory fitment until such time as it was clear that industry could support this. A mandatory date of May 2006 has now been agreed.
EU regulation 2135/98 allows the amendments to regulation 3821/85. There was been a delay due to negotiations between member states over the technical specification of the new tachograph, but this has been agreed and was published via EU regulation 1360/2002.
This regulation contains the new technical specification - Annex 1B, and you may hear these new tachographs referred to as a 1B tachograph. It should be noted that the regulation 3821/85 still exists, including Annex 1, but has been amended by this later legislation.
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What is a digital tachograph?
Digital tachographs are similar in appearance to a modular analogue tachograph e.g. 1324, 2400. They come in separate parts, a vehicle unit and a speedometer - but that is where similarities end. In all other aspects this is a totally different animal.
The Vehicle Unit (VU) is located within the driver’s area of the vehicle cab. It sends a signal to the speedometer / odometer unit that is located where the driver has a clear view of it. The vehicle unit still receives a signal from the vehicle (usually from the gearbox) as the analogue units do, via a cable.
The VU is the brains of the system. It is able to hold data on drivers of the vehicle and their periods of driving and duty for about a 12-month period. It will also hold data relating to faults, attempts to tamper with the system, over speeding, calibration details, and when data has been accessed, for example, by VOSA staff or Police.
The VU and the motion sensor from the gearbox will be encoded as a pair and the signals from the sensor will be fully encrypted so any attempt to interfere with them will be registered and recorded in the vehicle unit. [This is greater than the current modular tachographs]
The VU will be set to Universal Time Co-ordinated (UTC) - as another name for Greenwich Mean Time (GMT) - all records will be against this time. The visual display will probably be set to the local time, but this will not affect the internal time. What needs to be remembered is that the stored record will be an hour behind in British Summer Time - for example - a driver starts at 0600 (6am), the record will show 0500 (5am). There will be no difference in the winter as we are back to GMT.
Drivers, companies (operators), workshops (tachograph calibration centres) and enforcement officers (VOSA & Police) will each have smart cards according to their specific needs. These enable them to use and / or give access to the data in the VU.
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Page last updated: 01/02/2006