Protocol Operation Control

In the default config state, the controller is stopped. This is the power-on state.

In the config state, the controller is stopped. You can configure the controller in this state.

In the ready state, the controller can transition to the wakeup or startup states to perform a coldstart (startup of a bus) or integrate into a running cluster.

In the wakeup state, the controller can wake up nodes that are sleeping while the rest of the cluster is active.

The startup state is not a single state, but represents a state machine that is used for bus startup. The state machine has three different paths, depending on how the interface will participate in the startup process. The leading coldstart node is the interface that is initiating the schedule synchronization. The following coldstart node(s) are other coldstart-capable interfaces joining the leading coldstarter in starting up the FlexRay bus. The non-coldstart nodes connect to a currently running bus.

After properly integrating onto the bus, the controller transitions through the three operating states (Normal Active, Normal Passive, and Halt), which are similar to the CAN operating states of Error Active, Error Passive, and Bus Off.

When the interface is in Normal Active state, it is fully synchronized and supports cluster-wide clock synchronization.

When the interface is in Normal Passive state, it stops transmitting frames and symbols, but received frames are still processed. It still can perform clock synchronization based on received frames, but it does not contribute to the clock synchronization.

When the interface is in Halt state, all frame and symbol processing is stopped, as is macrotick generation.