ABB FCAN-01 User Manual page 110

110 Communication protocol
ARBITRATION FIELD
COMM.
START OF
OBJECT ID
FRAME
(COB ID)
1 BIT 11 BITS
(OR 29 BITS)
FUNCTION CODE
10 9 8
Communication
object
NMT
SYNC
TIME STAMP
EMERGENCY
PDO1 (Tx)
PDO1 (Rx)
PDO6 (Tx)
PDO6 (Rx)
PDO21 (Tx)
PDO21 (Rx)
SDO (Tx)
SDO (Rx)
NODEGUARD
Control field contents:
1 = IDE bit = 29-bit Extended identifier / 11-bit standard identifier (1 bit)
2 = r0 = reserved (1 bit)
3 = DLC = Data Length Code (4 bits)
Inside the CANopen data frame, different types of Communication
Objects are used to convey the data. Process Data Objects (PDO)
are used for transmitting time critical process data (references,
control commands, status information); Service Data Objects
(SDO) are used for less time critical data, for example, parameters.
Header
CONTROL
FIELD
REMOTE
TRANS-
MISSION
REQUEST
1 2 3
(RTR)
1 BIT 6 BITS
NODE ID
7 6 5 4
Function code
(binary)
0000
0001
0010
0001
0011
0100
0101
0110
0111
1000
1011
1100
1110
CYCLIC
DATA REDUNDANCY
FIELD CHECK
(CRC)
0 TO 8 16 BITS
BYTES
3 2 1 0
COB ID (hex) COB ID (dec)
00
80
100
81...FF
181...1FF
201...27F
281...2FF
301...37F
381...3FF
401...47F
581...5FF
601...67F
701...77F
ACKNOW-
END OF
LEDGE
FRAME
FIELD
2 BITS 7 BITS
0
128
256
129...255
385...511
513...639
641...767
769...895
897...1023
1025...1151
1409...1535
1537...1663
1793...1919