Networking automotive systems: CAN FD Databus Gateway

The CAN-FD data bus is based on the familiar high-speed CAN bus. “FD” means flexible data rate and describes a process in which the transmission rate of the user data essentially differs from that of the rest. This means that data can be transmitted at up to 8 Mbps. At the same time, the maximum amount of data is increased from 8 to 64 bytes.

The result of these two measures is that an 8 times longer message can be transmitted in a significantly shorter time with CAN-FD. The standard CAN bus and CAN-FD are largely compatible. Only a few control bits have been added to identify CAN-FD.

In this series of tests, both conventional high-speed data and the new CAN-FD data are compared. The signals are recorded both physically with the oscilloscope and digitally with appropriate protocol analysis hardware and then interpreted.

Students should already be familiar with the basics of the CAN bus structure.