A full range of Tachograph and Data Management products and Telematics. Data is stored as a .ddd file that can be imported into tachograph analysis software. Tachograph heads are of either analogue or digital types. Data can be locked in the tachograph head by using a company card. Depending on the relevant legislation, conversions may also involve wheelchair lifts and tachograph equipment. Investigators discovered that the coach's tachograph was missing the disc used to record speed. The tachograph unit records speed violations for each driver and gives a printed report. All commercial operation (not on a scheduled bus route) requires a tachograph. The tachograph was originally introduced for the railways so that companies could better document irregularities. A tachograph can be used to monitor this and ensure that appropriate breaks are taken.