CANFDNET-400U
High-performance Four-channel CANFD Bus-to-Ethernet Converter User Manual
©2021 Guangzhou ZLG Microelectronics Technology Corp.,Ltd.
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User Manual
message format is shown in Table 4.25 (using the CAN extended frame as an example,
the standard frame only has a different length of the frame ID, and other formats are the
same). The transmitted Modbus protocol content can then start with the "Data 2" byte. If
the protocol content is greater than 7 bytes, the remaining protocol content will continue to
be converted in this segmented format until the conversion is completed.
Table 4.25 CAN extended frame segmentation message format
Bit number
7
6
5
4
3
2
1
0
Frame
information
FF
RTR
0x00
0x00
DLC (data length)
Frame ID3
X
X
X
ID.28 - ID.24
Frame ID 2
ID.23 - ID.16
Frame ID1
ID.15 - ID.8
Frame ID0
ID.7 - ID.0
Data 1
Segment
marker
Segment type
Segment counter
Data 2
Character 1
Data 3
Character 2
Data 4
Character 3
Data 5
Character 4
Data 6
Character 5
Data 7
Character 6
Data 8
Character 7
For CANFD messages, the segmented message format is shown in Table 4.25 (using
the CANFD extended frame as an example, the standard frame only has a different length
of the frame ID, and other formats are the same). The transmitted Modbus protocol
content can then start with the "Data 2" byte. If the protocol content is greater than 63
bytes, the remaining protocol content will continue to be converted in this segmented
format until the conversion is completed.
Table 4.26 CANFD extended frame segmentation message format
Bit number
7
6
5
4
3
2
1
0
Frame
information
FF
RTR
EDL
BRS
DLC (data length)
Frame ID3
X
X
X
ID.28 - ID.24
Frame ID 2
ID.23 - ID.16
Frame ID1
ID.15 - ID.8
