Tacho Remaining Driving Times is an addition to our Remote Tacho Download solution. The uncalculated data acquired from the tachograph is, besides shown on the truck’s dashboard, also available on the manager’s device at the back office. This makes planning more reliable and efficient.
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Tachograph data via K-Line
All digital tachographs have a K-Line connection on pin 8 of the D-sub connector (D8 pin). The current tachograph data is transmitted via this connection and describes the current state of the tachograph, driver and the vehicle itself. This data is also transmitted when the vehicle is switched off, making it possible to detect tachograph activities if the driver changes his status when the vehicle is powered down. The Squarell FLEX and SOLID-K include a K-Line connector that can be used to connect to the D8 pin of all VDO, Stoneridge and Actia digital tachographs to read the current tachograph data.
The parameters supported by K-Line are:
- Work State of Driver 1 and 2
- Driver ID or Driver 1 and 2
- Driving Time Exceeded Warnings Driver 1 and 2
- Card Present
- Date and Time
- Tachograph Vehicle Speed
- Odometer
- VIN
- Vehicle Registration Number
Function | Order code | Remark |
---|---|---|
Work status Driver 1 (actual per second) | Standard | FMS interface with CAN input |
Work status Driver 2 (actual per second) | Standard | |
Driving time exceeded warnings Driver 1 | Standard | |
Driving time exceeded warnings Driver 2 | Standard | |
Card present 1 | Standard | |
Card present 2 | Standard | |
Tachograph vehicle speed | Standard | |
Tachograph date and time | Standard | |
Tachograph data at ignition off | Standard | Only with K-Line D8 connect |
Driver ID | Standard | Only with K-Line D8 connect |
Tachograph direction 0=forward 1 =reverse | Standard | Only with K-Line D8 connect |
Tachograph performance | Standard | Only with K-Line D8 connect |
Tachograph handling info | Standard | Only with K-Line D8 connect |
Tachograph event | Standard | Only with K-Line D8 connect |
What is a tachograph?
A (digital) tachograph is a device fitted to a vehicle that automatically records its speed and distance, together with the driver’s activity selected from a choice of modes: the drive mode is activated automatically when the vehicle is in motion and modern tachograph heads usually default to the other work mode upon coming to rest. The rest and availability modes can be manually selected by the driver whilst stationary.

Regulations vary from country to country
For reasons of public safety, many jurisdictions have limits on the working hours of drivers of certain vehicles, such as buses and trucks. A tachograph can be used to monitor this and ensure that appropriate breaks are taken. Drivers and their employers are legally required to accurately record their activities, retain the records and produce them on demand to transport authorities who are in charge of enforcing regulations governing drivers’ hours of service.
Tachograph download
How does it work
The digital tachograph stores continuous data in the internal memory and driver’s passport. The internal memory stores data from the last 365 days of the vehicle. Data stored on the driver’s pass must be downloaded every 21 days and data contained in the internal memory must be downloaded every 3 months. This data must be stored (in DDD files) so that the government can inspect it.
Obtaining the data can be done by going with a dongle or laptop to the vehicle and downloading the data (so the vehicle must be visited). However, it is also possible to read the data remotely via the CAN bus using Remote Tacho Download (RTD).
Squarell implementation
With a Squarell FLEX or SOLID (which has loaded the RTD profile), it is possible to perform the required downloads via the Remote Tacho Download without actually having to go to the vehicle. With this implementation, the transport company can put the company card in a card reader at the back office. The card reader is connected to the tachograph via the telematic service provider’s modem together with the FLEX or SOLID. Now, the (inserted) driver card and the vehicle data in the internal memory can be read. All data of the tachograph can be merged into DDD files to be saved and stored.

Tacho Remaining Driving Times
Tacho Remaining Driving Times and all our tacho related solutions are supported in VDO Counter digital tachographs since version 2.0a and Stoneridge DDS. For details, see below:
The following tachographs are supported by Squarell:
VDO Counter
VDO 2.0a (2012 & 2013)
VDO 2.1 (2013 & 2014): needs to be activated
VDO 2.2 and higher (2015+)
VDO 4.0 (2018+)
Stoneridge DDS
Stoneridge Exakt Duo 7.4 (2012 & 2013 & 2014)
Stoneridge Exakt Duo 7.5 (2014+)
With VDO Counter, all drivers are able to plan their driving and rest times more efficiently. With one glance at the VDO display, you know immediately the remaining driving times and the duration of the next rest period. You can easily see the maximum driving time after each rest period and also the remaining driving times for that day or the week.
Squarell implementation
Squarell can extract the VDO Counter parameters from the digital tachograph. The extraction can be done on the remote download CAN bus from the tachograph located on the back of the tachograph.
Customers that already have tacho download, can easily upgrade to this new functionality. Customers that do not have tacho download, first need to connect the tacho download CANbus from the FLEX/SOLID to the digital tachograph. To activate the Tacho Remaining Driving Times in the FLEX or SOLID, a special profile is needed. The profile can be activated after purchasing, and it has ‘RDT’ in its name.
The parameters supported by the new RDT functionality are:
- Total Time Of The Current Work State
- Total Drive Time Of The Current + The Previous Week
- Remaining Drive Time Of The Current/Next Period
- Remaining Time Before The Next Break
- Time The Next Break Should Be
- Remaining Time Of The Current Break
- Remaining Time Before The Next Drive Period
- Duration Next Drive Period
- Remaining Daily Drive Time
- Remaining Time Before The Next Daily Break
- Time The Next Daily Break Should Be
- Remaining Drive Time Of This Week
- Remaining Time Before the Next Weekly Break
- Time The Next Weekly Break Should Be
- Compensation Time Of The Previous Week
- Compensation Time Of The 2nd Previous Week
- Compensation Time Of The 3rd Previous Week
- Remaining Daily Extended Drive Time Periods
- Remaining Daily shortened Rest time Periods
Why do I need Tacho Remaining Driving Times?
The remaining driving times can be manually calculated by monitoring the real-time data coming out of the tachograph. Research has proven that even the best routines calculating these times are a few minutes off in the best scenarios. But when the monitoring device is disconnected, powered down or when the driver manually adds an entry when he enters his Driver Card, great differences can occur between the calculated values and the real values that are shown on the screen of the tachograph.
Uncalculated data is never wrong
The Squarell Tacho Driving Times are never wrong because they come directly from the tachograph. It is plug and play because the data can be immediately retrieved from the tachograph and does not have to be calculated (when it is calculated, the two-week history is unknown and therefore, calculated data needs a startup time of two weeks). Another advantage is, there is no incorrect data when the FLEX or SOLID gets disconnected or when the driver manually adds an entry. And finally, the data Squarell presents is the same as the data displayed on the tachograph and the data the driver is seeing.