GB/T 41588.4-2022 Road vehicles—Controller area network(CAN)—Part 4:Time-triggered communication

Scope

This document specifies the time-triggered communication protocol in a Controller Area Network (CAN), a serial communication protocol that supports distributed real-time control and multiplexing.
This document is applicable to the establishment of time-triggered digital information interaction between electronic control units (ECUs) equipped with CAN buses in road vehicles, and it specifies a frame synchronization entity implemented according to the logical link and media access control in ISO 11898-1, used to provide a time-triggered communication schedule.
Note: Time-triggered CAN adds an upper-layer protocol to the CAN bus protocol, where the CAN protocol remains unchanged in time-triggered CAN. Time-triggered communication ensures that the delay time of all messages remains at a specific value, regardless of the load rate of the CAN bus. Time-triggered communication includes the following two levels: Level 1 is limited to periodic message transmission, while Level 2 supports global system time. The periodic communication of time-triggered CAN is based on the reference message sent by the time master node. Each cycle starting from the reference message is called a basic cycle, and the time period of this cycle is subdivided into several time windows. The reference message is used to synchronize and correct the time base of all nodes, ensuring that all nodes maintain a consistent time base with the master node and providing a global time for the entire network. Time-triggered CAN provides a backup time master node mechanism to replace a failed time master node.

Development Information

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