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4.3 CAN-Messages
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• 11-bit identifier (Base/standard frame format)
• 29-bit identifier (Extended frame format)
Furthermore the identifier is used for prioritisation of messages. A high priority guarantees that the message is send with the shortest possible latency. Due to the specification to avoid arbitrary conflicts two or more transmitters are not allowed to use the
same identifier.
4.3 CAN-Messages
Figure 4.2: Structure of a CAN message [17]
Generally the CAN communication is established using four different types of messages:
Data frames
which transmit up to eight bytes of data.
Remote frames
which request data frames from another device connected to
the bus.
Error frames
which indicate an error via broadcast to all network
participants.
Overload frames which provide a timeout between data and remote frames.
A data frame has the following structure:
M M Labus
University of Ulster