Campbell Scientific SDM-CAN Datalogger to CANbus Interface User Manual
Page 70
Appendix D. Examples of CAN Data Frames and Data Encoding and Decoding
32bit data frame with two 16bit signed integer values MSByte first
Rxed Bit order within bytes
87654321 87654321 87654321 87654321
Rxed Byte order
Byte 1
Byte 2
Byte 3
Byte 4
Values
S B
S A
Bit order within values
16 9
8 1
16 9
8 1
Value byte order
MSByte
LSByte
MSByte
LSByte
Start bit (parameter 09:) RH ref
32 25
24 17
16 9
8 1
Start bit (parameter 09:) LH ref
1 8
9 16
17 24
25 32
S = sign bit which is the MSBit of the values, bit 16.
Start bit (parameter 09:) Right Hand reference.
1: SDM-CAN (P118)
1: 0
SDM
Address
2: 1
Time-quanta
3: 5
Tseg1
4: 2
Tseg2
5: 1000
ID
Bits
0..10
6: 0000
ID
Bits
11..23
7: 00
ID
Bits
24..28
8: 3
Rx, signed int, MSB 1st
9: 1
Start
Bit
No.
10: 16
No.
of
Bits
11: 2
No.
of
Values
12: 1
Loc [ value_A ]
13: 1.0
Mult
14: 0.0
Offset
Start bit (parameter 09:) Left Hand reference.
2: SDM-CAN (P118)
1: 00
SDM
Address
2: 1
Time-quanta
3: 5
Tseg1
4: 4
Tseg2
5: 1001
ID
Bits
0..10
6: 0000
ID
Bits
11..23
7: 00
ID
Bits
24..28
8: 3
Rx, signed int, MSB 1st
9: 32
-- Start
Bit
No.
10: 16
No.
of
Bits
11: 2
No.
of
Values
12: 1
Loc [ value_A ]
13: 1.0
Mult
14: 0.0
Offset
D-8