Contrôle de vitesse par balises
Contrôle de Vitesse par Balises (Speed control by beacons), abbreviated to KVB[note 1] is a train protection system used in France and in London St. Pancras International station.[1] KVB consists of: The on-board computer generates two speed-thresholds based on the received signals from the balises.If the second speed threshold is passed, the KVB automatically engages emergency brakes on the train.The next revisions evolved towards a Motorola 68020 processor and the software was re-written using the B-Method.KVB is comparable to ETCS Level 1 Limited Supervision because it offers a beacon-based speed control without any indication for the driver.