ISO 17458-2-2013 pdf free download

ISO 17458-2-2013 pdf free download.Road vehicles— FlexRay communications system — Part 2:Data link layer specification
Véhicules routiers — Système de communications FlexRay — Partie 2: Specification de Ia couche de liaison de données.
process in question is stalled until all other process have executed. Should multiple processes be in a state where they are sensitive to a priority input, all are executed last and in random order. The message queue is handled in the standard way, i.e. the signal triggering the priority input is removed from the queue while any signals placed before or after are preserved for the succeeding state.
5.3.3.6 Signals to non-instantiated processes
In various portions of the SDL behavioural descriptions the SDL sends signals that are received by a process that in some conditions may not be instantiated, As an example, the SDL in Figure 30 generates the signal CODEC control on B (NORMAL) even if the node is only attached to channel A (implying that the CODEC_B process is not instantiated). The sending of these signals should not be interpreted as requiring that processes that receive the signal should be instantiated – in such cases these signals should simply be ignored. This convention holds even if the only process that consumes the signal in question is a process that is not already instantiated.
5.3.3.7 Exported and imported signals
Certain features of the FlexRay protocol require that a certain direct communication between the two communication controllers of a time gateway is modeled within the SDL diagrams (for example, see 5.6.4). Signals marked with the EXP keyword are distributed within the local communication controller like any other signal, but are in addition are also forwarded to a second communication controller that is represented by a separate instance of the SDL diagrams. On the receiving end, these exported signals can be received by input symbols marked with the IMP keyword. Input symbols marked in this way are only sensitive to signals emitted with the EXP keyword of the other communication controller.
5.4 Bit rates
The FlexRay Communications System specifies three standard bit rates — 10 Mbit / s (corresponding to a nominal bit duration. gdBit, of 100 ns), 5 Mbit Is (corresponding to a gdBit of 200 ns), and 2,5 Mbit/ S (corresponding to a gdBit of 400 ns). In order to be considered FlexRay conformant, a protocol implementation is required to support all three standard bit rates.
5.5 Roles of a node in a FlexRay cluster
There are three distinct roles a node can perform.
The role of a sync node enables a node to actively participate in the clock synchronisation algorithm performed by the cluster. Sync nodes transmit sync frames that are evaluated by all nodes of the cluster to perform an alignment of clock rate, that effectively determines the cycle length, and clock offset, that effectively determines the position of the cycle start.
— The role of a coldstart node enables a node to initiate the communication. Coldstart nodes are allowed to start transmitting startup frames in the non-synchronized state with the intent of establishing a schedule.ISO 17458-2-2013 pdf free download.