Cp3 bt26 – National CP3BT26 User Manual
Page 113
113
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CP3
BT26
A CAN data frame consists of the following fields:
Start of Frame (SOF)
Arbitration Field + Extended Arbitration
Control Field
Data Field
Cyclic Redundancy Check Field (CRC)
Acknowledgment Field (ACK)
End of Frame (EOF)
Remote Frame
Figure 38 shows the structure of a standard remote frame.
Figure 39 shows the structure of an extended remote frame.
Figure 38.
Standard Remote Frame
Figure 39.
Extended Remote Frame
A remote frame is comprised of the following fields, which is
the same as a data frame (see CAN Frame Fields on page
111) except for the data field, which is not present.
Start of Frame (SOF)
Arbitration Field + Extended Arbitration
Control Field
Cyclic Redundancy Check Field (CRC)
Acknowledgment field (ACK)
End of Frame (EOF)
Note that the DLC must have the same value as the corre-
sponding data frame to prevent contention on the bus. The
RTR bit is “recessive”.
STANDARD REMOTE FRAME (number of bits = 44)
Control Field
END OF
FRAME
CRC Field
CRC
Arbitration Field
IDENTIFIER
10 ... 0
11
ST
AR
T OF FRAME
ID 10
ID0
ID3
RT
R
IDE
RB0
d
d d d
r
r r
r r
r r
r r
CRC DEL
A
CK DEL
A
CKNO
WLEDGEMENT
15
4
16
DATA
LENGTH CODE
DLC3
DLC0
Note:
d = dominant
r = recessive
DS022
EXTENDED REMOTE FRAME (number of bits = 64)
Control Field
END OF
FRAME
CRC Field
CRC
Arbitration Field
IDENTIFIER
28 ... 18
Note:
d = dominant
r = recessive
11
4
DATA
LENGTH CODE
ST
AR
T OF FRAME
ID 28
ID18
ID17
ID0
SRR
IDE
RT
R
RB1
RB0
DLC3
DLC0
d
r r
r d d
r
r r
r r
r r
r r
CRC DEL
A
CK DEL
SCK
18
15
16
IDENTIFIER
17 ... 0
DS023