J1939 Protocol - Woodward easYgen-2000 Series User Manual

Interfaces And Protocols

J1939 Protocol

Octet Number 1.
UNSIGNED56 b to b
7 0
UNSIGNED64 b to b
7 0
Table 92: Transfer syntax for data type UNSIGNEDn
Data format "Signed Integer"
Octet Number 1.
SIGNED8 b to b
7 0
SIGNED16 b to b
7 0
SIGNED24 b to b
7 0
SIGNED32 b to b
7 0
SIGNED40 b to b
7 0
SIGNED48 b to b
7 0
SIGNED56 b to b
7 0
SIGNED64 b to b
7 0
Table 93: Transfer syntax for data type INTEGER
7.5 J1939 Protocol
456
2. 3. 4.
b to b b to b b
15 8 23 16 31
b to b b to b b
15 8 23 16 31
SIGNED type data has integers as values. The range is between 0
and 2 n-1 . The data is shown by the bit sequence of length n.
Bit sequence:
n
b = b to b
0
Value shown:
n
SIGNEDn(b) = b
if b = 0
n-1
And with two's complement:
n
SIGNEDn(b) = SIGNEDn(^b)-1
if b = 1
n-1
Please note that the bit sequence starts on the left with
the least significant byte.
Example: The value -266 = FEF6 hex of type
SIGNED16 is transmitted in two octets, first F6 hex
and then FE hex.
2. 3. 4.
b to b
15 8
b to b b to b
15 8 23 16
b to b b to b b
15 8 23 16 31
b to b b to b b
15 8 23 16 31
b to b b to b b
15 8 23 16 31
b to b b to b b
15 8 23 16 31
b to b b to b b
15 8 23 16 31
The J1939 protocol is using an extended CAN identifier and can be
used via CAN bus interface parallel to the CANopen protocol and
ToolKit. All devices connected to the CAN bus interface must use
the same baud rate independent of the selected protocol.
easYgen-2200/2500 | Genset Control
5. 6.
to b b to b b to b
24 39 32 47
to b b to b b to b
24 39 32 47
n-1
* 2 + ... + b
n-2
n-2 1
5. 6.
to b
24
to b b to b
24 39 32
to b b to b b to b
24 39 32 47
to b b to b b to b
24 39 32 47
to b b to b b to b
24 39 32 47
7. 8.
b to b
40 55 48
b to b b to b
40 55 48 63
* 2 + b * 2
1 0
0
7. 8.
40
b to b
40 55 48
b to b b to b
40 55 48 63
37535B
56
56