Ebicab principles are subsequently used in KVB and RSDD systems and also for the ERTMS ETCS balises. During the 1980s, other cab computers were introduced to read the older signalling and to overlay it with better control. The German PZ80 was able to check the speed in steps of . The French KVB replaced the external system with balises in the early 1990s to transmit a combined information for oncoming signal aspects and the allowed train speed. Siemens did also invent a successor to the PZB signalling that was deployed as in Switzerland since 1992 and in Denmark since 1992. ABB improved the external balises in the EBICAB 900 system which as then adopted in Spain and Italy. Siemens had presented a study on balise systems in 1992 which influenced the choice of using a technology based on KVB and GSM instead of LZB when the European Rail Traffic Management System was researching a possible train signalling for Europe. The first Eurobalises were tested in 1996 and later train protection systems used them as a basis for their signalling needs. See also Automatic Warning System Cab signalling EBICAB Linienzugbeeinflussung Positive Train Control Train Protection & Warning System References External links SUBSET-036 Specification for Eurobalises (PDF; 1,12 MB) Beijing Railway Signal Factory Train protection systems