Find the instructions for performing coldstarts here.
The VBOX Speed Sensors have default settings applied so that you can use them straight out of the box. You can, however, also configure the settings for your Speed Sensor, by using the VBOX Setup software, which you can download here. Find more information about how to configure your VBOX Speed Sensor here in the VBOX Speed Sensor User Guide.
You can use the Digital Input on the VBOX Speed Sensor to program the position of virtual lines which lets you set Start/Finish and Split lines. Racelogic can provide different triggers and switches to use with this feature. For more information on available Digital input accessories, click here.
Read more about how you can configure your VBOX Speed Sensor to set the function of the Digital Input to either Lap pulse or Brake Trigger mode here.