Chapter 4
Example Application 4-1
© 2002 HMS Industrial Networks
Document Id:
SCM-7801-026
Example Application
Scenario
A system controller (PLC) on Modbus requires some data that is collected by an
ECU on J1939. There is also a piece of data that is determined by the system con-
troller that would be beneficial for some of the ECUs that are on the J1939 net-
work.
The data required by the system controller is contained in the PGN 4608 message
as 2 12-bit values. The values are packed into the first 3 bytes of the message as
shown in Figure 4-2 below.
The data from the system controller is to be produced using PGN 256. The data is
a 16-bit value and will be placed into the first 2 bytes of the message data.
Figure 4-1 Example Application Network Diagram
Bit
Byte
7
6
5
4
3
2
1
0
0
Value #1 bits 0-7
1
Value #2 bits 0-3
Value #1 bits 8-11
3
Value #2 bits 4-11
Figure 4-2 Example PGN 4608 Message Data Format
System
Controller
AnyBus-X
ECU-1
ECU-2
ECU-3
M
odbus
J1939
PGN 4608
PGN 256
Содержание AnyBus-X J1939
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