The CVCI protocol chip will be integrated into your telematics
hardware and allows access to the commercial vehicle data via the
- FMS CAN
- CAN of the digital tachograph
- D8 info link of the digital tachograph
With these connections not only the complete real-time vehicle
operational data and the ID numbers of the driver cards are available
but also access to the data storage of the digital tachograph. Using
CVCI chip as access device to the vehicles electronics the telematics
unit is able to download the complete tachograph data for archival
storage without any manual intervention. The laborious and error-prone
handling of the USB Download Stick is a thing of the past.
The CVCI chip is based on an LPC2364 from NXP and comes in an LQFP
100 housing. Only two CAN transceivers, two crystals, two diodes and
some capacitors and resistors are required as external circuitry.
Communication with the host system is via UART. With an internal clock
speed of 72 MHz, this controller also provides sufficient reserve for
future firmware extensions.
All messages defined in the FMS Standard 03 (truck and bus) are
supported by the CVCI chip. If the vehicle is equipped with FMS version 2
or 3, the connection of the D8 Info interface can generally be omitted
because the information about inserted driver cards is provided by the
new FMS standards.
D8 Info Interface of the digital tachograph
digital tachograph features a serial output on its rear panel, where
the driver’s card data and some vehicle operational data are transmitted
cyclically. Unfortunately the data format is not specified in the EU
regulation paper and therefore the tachograph manufactures use different
data formats. In its actual revision the CVCI chip supports the VDO and
the Stoneridge formats, other tachographs will be added on request.
The Remote Download function via FMS CAN has been published end of
2008. The CVCI chip grants access to this helpful feature without having
to learn the related CAN protocol. A special UART protocol provides
access to authentication and data download. On the telematics host side
we provide a run time API which realizes most of the programming tasks
and facilitates building the Remote Download application. The API offers
the functions to open a session, to realize the authentification
processs and to download the tachograhp’s and the driver cards data. To
further facilitate the programming work the example application which is
delivered with the CVCI chip is available as a source code package.
With the help of the Remote Download function companies are able to
fulfil the compulsory archiving without manual intervention of the
driver. Data downloaded by the Remote Download Function contains a
digital signature as requested by the law in most European countries. If
the vehicle does not yet support the Remote Download feature on the CAN
FMS the CVCI chip can be connected to the rear panel of the digital
The CVCI chip can be parameterised by a lot of useful parameters and
in this way be adapted to nearly any special demands of a given
telematic application. The telematics host is not bound to read all the
real time variables. With the help of parameterrising commands the
variables are selectable by masks as well as the time or distance period
of the output cycle.
Output of Real Time Values
Sample output in the DebugOutput format
The cyclic output of realtime values can be done in two different
formats. The so called debug format is used for the initial operation
procedure and for monitoring after modification of parametrising. In
normal operation mode when data is transmitted to the telematic host a
compressed format is used, where no leading text and no physical units
are output. In this format the values are separated by semicolons and
can be prefixed by an optional index value.
Sample output of table format with indexes