CAN FD - Migrate machines and plants easily

Due to its high data security, the CAN bus has also established itself outside of automotive applications and has long been used in industrial automation as well as in safety-relevant areas.

With the further development to CAN FD (Flexible Data Rate) and the standardization in ISO 11898-1:2015, the way is clear for powerful CAN FD applications with speeds of up to 10 Mbit/s and 64 bytes of user data. CAN FD is an option especially where self-contained machine units are to be given better performance with little effort: Up to 8 times higher data throughput can be achieved with the same cabling and infrastructure.

As with the classic CAN protocol, the driving force behind the CAN FD (CAN with flexible data rate) protocol was the automotive manufacturers. In cooperation with Bosch and other experts, work began in 2011 on a solution with the aim of pushing back the existing limits of classic CAN in terms of the maximum achievable data rate or data throughput. At the same time, the proven concepts of the classic CAN protocol (real-time capable bus arbitration, event control, 11- and 29-bit identifiers, multimaster capability) were to be retained. These include, among other things, high robustness against interference, low power requirements, and the use of existing topologies.

The intended goals were achieved by:

• Retaining the classic CAN concepts in the arbitration and acknowledgement phase as well as in error handling.
• Increasing the bit rate in the data phase from the previous maximum of 1 Mbit/s to up to 8 Mbit/s [1] and more.
• Increase in the number of data bytes transmitted in a CAN message from the previous maximum of 8 to 64 bytes.