CAN FD – ISO 11898-1

By extending the classic CAN fieldbus to CAN FD – CAN Flexible Data Rate – higher performance can be achieved with less effort in applications.

The fieldbus is standardized according to ISO 11898-1: 2015 and enables the improvement of already existing closed systems with higher transmission rates and more user data per message.

Function

CAN Flexible Data Rate – short CAN FD – is the further development of the “conventional” CAN bus system. In accor­dance with the requirements of the auto­motive industry, the system has a flexible data rate. In 2011, Bosch began devel­oping the CAN FD standard in colla­boration with vehicle manu­facturers and CAN fieldbus experts.

In comparison to CAN, a higher and faster data transmission can take place. The pre­vious 8 bytes as payload were increased to 64 bytes with a possible transfer rate of up to 10 Mbit/s (comparable to CAN 1 Mbit/s).

Application

In the area of electronic control units, higher bandwidths are often required, as is the case when downloading software. The possible 64 bytes of user data makes it possible to inte­grate a gateway between CAN FD and Ethernet. Due to the similar structure between CAN and CAN FD, systems that already use CAN can easily be converted to CAN FD using the existing wiring. Thanks to the error detection mechanisms, the protocol can also be used in safety-relevant areas. CAN FD can be used for both 11-bit identifiers and 29-bit identifiers.