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Grundlagen FlexRay BasicsV 1.1 29
since it is shortened by every Bus Driver for latency reasons. After that, the Frame Start
Sequence (FSS) starts, which is used as a safety buffer against quantization error while bit
sampling.
After that, the actual frame starts. In front of every byte, a Byte Start Sequence (BSS) is
transmitted, to help bit synchronization. After the last byte, the static frame is delimited by an
Frame end Sequence (FES).
In Figure 2.25 and Figure 2.26 you can also see the signals TxD and TxEN, which are
generated by the Communication Controller while transmitting.
In a frame in the dynamic segment (Figure 2.26), the FES is followed by a Dynamic Trailing
Sequence (DTS).. It is a Low phase with variable length, which extends every frame until the
next Media Access Control (MAC), to enable an exact assignment to the Minislot-ID. The
dynamic frame is delimited by the High bit of the DTS. The bus goes to Idle level after that.
Figure 2.26 Dynamic Segment [FRPS05]
Bäurle 12.10.2012