CAN categories

Today's motor vehicles already network together a large number of control units. Some of these control units are used for applications which have special requirements. Therefore several CAN bus systems are installed in an automobile. These are mostly differentiated by their transmission speed and are therefore divided into two categories:

• CAN buses with a transmission speed of less then 125 kbit/s are called  "low speed buses".
• Faster CAN buses belong to the "high speed buses" and reach transmission speeds of up to 1000 kbit/s (= 1 Mbit).

High speed CAN buses have smaller voltage levels and shorter bit times than low speed buses. Therefore low speed buses are less sensitive to interference and can be run with only one data line (e.g. with Opel).