When a tachograph and associated speed sender are installed in a vehicle they must be 'paired'
before use. The pairing process sets up the encryption mechanism used for communication between
sender and tachograph. The process also records in the tachograph the serial number of the paired
speed sender. During periodic inspections of the tachograph installation there is a requirement
to confirm that the speed sender in the vehicle's gearbox is the one recorded in the tachograph.
The Lisle Design Speed Sender Reader makes it easy to carry out this check.