C.5.2 finding the start bit, C.5.2 – Campbell Scientific SDM-CAN Datalogger to CANbus Interface User Manual
Page 61
Appendix C. Application of the SDM-CAN on Networks Complying with the J1939 SAE Standards
C.5.2 Finding the Start Bit
The byte number of the Accelerator pedal position value is 2
TABLE C-7. Accelerator Pedal Position Value Byte Number
1
2 3 4 5 6 7 8
87654321
87654321 87654321 87654321 87654321 87654321 87654321 87654321
The start bit for this value is 49, as it is the least significant bit of the data value
within the data frame that this parameter refers to.
An example for Accelerator pedal position is shown below.
;{CR23X}
;
*Table 1 Program
01: 1.0
Execution
Interval
(seconds)
;Retrieve Accelerator pedal position Data from CAN network
8: SDM-CAN (P118)
1: 0
SDM
Address
2: 4
Time
Quanta
3: 5
Tseg1
4: 2
Tseg2
5: 768
ID Bits 0..10 (-- for 11-bit CAN ID)
6: 7680
ID
Bits
11..23
7: 12
ID
Bits
24..28
8: 2
Rx, unsigned int, LSB 1st
9: 49
Start
Bit
No.
10: 8
No.
of
Bits
11: 1
No.
of
Values
12: 7
Loc [ Throttle ]
13: 0.125
Mult
14: 0.0
Offset
*Table 2 Program
02: 0.0000Execution
Interval
(seconds)
*Table 3 Subroutines
End Program
C-5