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Communication extension card
-19-
Frame
header
Arbitration field
1 bit
11 bits
1 bit
6 bits
0
–
8 bytes
15 bits
1 bit
1 bit
1 bit
7 bits
Function code
Node identification (communication address)
9
8
7
6
5
4
3
2
1
0
1 0
Identifier of the
communication object
(COB-ID)
Remote
transmission
request
Control
field
Data field
CRC
sequence
CRC
delimiter
Response
delimiter
Response
interver
Frame
footer
Figure 3-2 Packet structure
Communication
object
Function code
(binary)
COB-ID (hexadecimal)
NMT
0
0x00
SYNC
1
0x80
EMERGENCY
1
0x81
–
0xFF
PDO1 Tx
11
0x181
–
0x1FF
PDO1 Rx
100
0x201
–
0x27F
PDO2 Tx
101
0x281
–
0x2FF
PDO2 Rx
110
0x301
–
0x37F
PDO3 Tx
111
0x381
–
0x3FF
PDO3 Rx
1000
0x401
–
0x47F
PDO4 Tx
1001
0x481
–
0x4FF
PDO4 Rx
1010
0x501
–
0x57F
SDO Tx
1011
0x581
–
0x5FF
SDO Rx
1100
0x601
–
0x67F
Node protection
1110
0x701
–
0x77F
COB-IDs vary according to communication address, but for one command, the COB-IDs are within a certain
range.
Note:
The commands described in this manual are all data frames if it is not specified that they are remote
frames.
3.4.2
CANopen state transition
The start sequence defined in the CANopen communication protocol is supported.
NMT state transition diagram.