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RACELOGIC Support Centre

04 - Speed Sensor Configuration


Hardware connection

Configuration of the VBSS is performed using VBOX Setup software, which can be downloaded here. Using the supplied RLCAB093 loom, connect the serial plug to the computers serial port – this can be done via a serial > USB convertor if required.

Software connection

Use the drop down list to select the correct COM port that the speed sensor is connected to. Click the connect button to enter the VBSS setup screen. Note: An auto detect message may appear if the baud rate has been changed from the default value– select ‘Yes’ to allow the different baud rates to be scanned.


Setup options


  Speed Sensor VBS General.png

  1. Connection – Selected com port, refresh and disconnect buttons.
  2. Load/Save – Load/Save settings from/into an .sscfg file. This allows setups to be kept for future use.
  3. Language – Select an operating language.
  4. Diagnostics – Displays live GPS data and basic current setup. GPS Info shows details on fitted GPS engine.
  5. Write to unit – After making changes to setup, the write to unit button must be selected to upload settings.
  6. GPS Information – Technical details about the GPS engine installed in the connected unit.
  7. VBOX Information – Software version, serial number and installed firmware version of connected unit.
  8. GPS Coldstart – Clears almanac stored in the GPS engine. Only to be used when struggling to gain SAT lock.




  1. Baud Rate The software has four common baud rate values: 1.00 MHz, 500 kHz, 250 kHz or 125 kHz.  
    The user also has the option to select a custom baud rate.

  2. CAN termination Resistance The internal CAN termination resistance can be enabled or disabled here.
  3. CAN delay - Only available on 100 Hz units. Enabling this feature will fix the CAN latency at 15.5 ms. Note that only Speed on CAN ID 302 will be transmitted when enabled.  
    For further detail on the CAN delay function, click here.
Transmitted Identifiers


  1. Send To switch a CAN message on/off, tick or un-tick the box for the corresponding message.
  2. Default / Actual ID  This allows the user to modify the CAN IDs transmitted by the Speed Sensor.  Default values are the Racelogic standard ID’s of 0x301, 0x302 …. 0x307.
  3. Standard/Extended To change the identifier format from standard 11bit to extended 29bit tick the ‘Extended’ box in the corresponding column.
  4. Parameters Shows which parameters will be sent out in each message.



  1. DGPS Mode This gives the user the option to select whether the Speed Sensor uses differential GPS: 
    None:  Differential GPS is off.
    SBAS: SBAS differential corrections are received from the nearest Geo-stationary GPS-SBAS satellite.
    RTCM: RTCM corrections are received by the VBSS via a Racelogic telemetry module and a locally placed Base station. Contact Racelogic or your local agent for more details.
  2. GPS Optimisation This option allows the user to change the sensitivity of the GPS engine.
    For high dynamic applications such as brake stop testing, this should be set to High.
    For less dynamic applications, such as steady state speed measurement or coast down testing, this can be set to Low.

  3. Slip Angle Settings  Here the user is able to enable or disable twin antenna mode, set roll mode and configure slip translation channel offsets.
  4. GPS Settings Change the update rate of the GPS engine and set a minimum speed output value and elevation mask, if required. 
    The Leap second value was increased to 18 seconds as of December 2016 - for more information on this, click here
    Note: The elevation mask feature is only available on Dual Antenna Speed Sensor units.


The serial output screen allows the user to configure the format, content and data rate of the serial stream transmitted by the Speed Sensor.


  1. Mode This selects which format the Speed Sensor will output Serial data in. NMEA message format is the only user configurable setup. 

    Racelogic: For Serial coms with other Racelogic products.
    Brake test: For use with Racelogic Brake Test Software.
    NMEA: For user defined NMEA message output.


  2. NMEA Messages If the NMEA message format is selected, the following options become available.

    Baud Rate: The required serial baud rate can be selected from this drop down menu.
    Update Rate: The update rate of the NMEA messages can be changed using this drop down list.
    Message Selection: NMEA messages can be selected and deselected for transmission by checking and un-checking the boxes next to each message type.

    Click here for Speed Sensor Serial Output protocols


Analogue output

Speed – Enter the maximum for the speed range you wish to measure. Default speed is set to 400 km/h. The maximum speed at 5V can be in the range 10 – 1000 km/h.


Lap Pulse When this option is enabled the VBSS will output a 5 V pulse when a Start/Finish line is crossed. The duration of the pulse in milliseconds can be adjusted by entering a different value. The polarity of the pulse can be changed to either a rising or falling pulse by clicking the ‘Polarity’ button.


Lateral / Longitudinal Acceleration Select the range you wish to use from the pull down list.


Digital Output

Speed The speed output is configured by changing the number of pulses per metre. Default = 90 pulse per metre => 25 Hz per km/h.


GPS Sync Selecting this option outputs a pulse every second, which is synchronised to the GPS clock.
Note: This feature is an optional extra which is not available by default. A GPS engine update is required to allow this to work correctly.


Lap Pulse When this option is enabled the VBSS will output a 5 V pulse for 300 ms when a Start/Finish line is crossed. The duration of the pulse in milliseconds can be adjusted by entering a different value.

The polarity of the pulse can be changed to either a rising or falling pulse by selecting the marker next to the desired image.


Digital Input

The Digital Input can be used to program the position of virtual lines in the Speed Sensor allowing for the setting of Start/Finish and Split lines. You must first ensure that you have a connection to the Lap Input (pin 6). This pin should be connected to one side of a momentary switch and the other side of the switch connected to the Ground pin of the VBSS, so that when the switch is pressed the Lap Input pin will be shorted to Ground. The Digital Input can also be used for a Brake Trigger. 


VBOX Setup Software should be used to set the function of the Digital Input to either Lap pulse or Brake Trigger mode.  


Lap pulse mode

Set a Start/finish line: Press and immediately release the Lap input switch as you cross the start finish line. You must be moving >5 km/h to do this and following the normal line along the track. The VBSS notes the point and direction of travel, then creates a virtual line perpendicular to your line of travel 25 m wide.

Set a separate Finish line: press hold the switch for >1.5 seconds before releasing. After you have set a Start/Finish or Finish line you can view the Latitude and longitude of this line position in the ‘Tests’ page of the setup software. If the software was already connected then press ‘Connect’ again to refresh the settings.

Set a Split line: Press the button twice for a very short period, when this has been marked, the 2nd LED flashes quickly 5 times. The output from the split line should be identical in all respects with the first.

To clear all Virtual lines: Press the button shortly once followed by a longer button press (longer than 1.5 seconds). In each case the VBSS will recognise the lead edge of the first pulse as the activation in order to set the associated virtual line at the exact point that the user first presses the switch.

Coldstart: This can be performed by grounding the input while connecting the VBSS to power - all LEDS will show Red.

Brake Trigger mode 

Enabling this mode allows the Digital Input to be used with a brake trigger. Activation of the trigger will start the brake stop distance measurement, where the VBSS will calculate a Time and Distance for a Brake Trigger to 0 km/h test. 



  1. Deceleration Here the start and end speed of non-trigger deceleration tests can be configured.

    Auto Corrected Distance Start Speed – This sets the speed sensor to use the nearest rounded 10 km/h speed when the trigger is activated. For example, if the trigger speed was 104 km/h then 100 km/h would be the nominated start speed for the corrected brake stop distance.

    Corrected Distance Start Speed – If the auto option is not selected, the user is able to specify a speed value to correct all deceleration tests to.
  2. Lap Timing

    Gate Width
    This sets the width of any gates set in the software. This is a useful feature when two parts of a track run very close to each other, or the pit lane is next to the start/finish line, as lowering this value can stop the virtual line being triggered by the incorrect area of the circuit.

    Time before retrigger This allows the user to set a number of seconds during which the brake trigger will not be reactive after having been pressed. This is to avoid trigger bounce during tests.

    CAN Pulse Width This option controls the duration of the lap time and splits CAN pulse. Other lap timing CAN channels such as Lap Marker, SF crossing pulse or gate crossing pulse marker set to 1000 ms duration as default. or the highest analogue or digital pulse duration setting, if greater. CAN pulse width can not exceed any Digital or Analogue Lap pulse output duration. If an invalid setting is set, Config will not allow writing to unit. Hovering over the Write to unit button will report invalid setting.

    Note: For a Lap beacon pulse to be output by the VBSS ensure valid virtual gate(s) have been loaded.
  3. Splits – Use the ‘Load all’ button to load a .SPL or .DSF file containing start/finish and split gates. Optionally, load split points, finish line or S/F line separately, using the separate ‘Load’ buttons.
    Files loaded via these buttons will have the selected information only loaded from them –i.e. a file containing a start/finish gate and 6 splits will only load the start/finish gate when loaded via the Start/Finish ‘Load’ button.
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