Revision 1.1
Appendix B – Application Note
Page B5
Figure 4 – Two Engines, Dual J1939 Networks
J1939
Engine
J1939
Display
J1939
Engine
J1939 Network #1
J1939 Network #2
Starboard Engine Connection
Port Engine Connection
Unlike the single J1939 network shown in Figure 3, the dual J1939 network scheme shown in
Figure 4 does not require the engines to have unique J1939 addresses. This is because the
display can determine which messages or PGNs are from which engine by the physical
connection on the display unit. In this scheme, each engine usually uses a source address of
zero (0).
3.1 SAE J1939 Recommended Cabling and Connectors
Maretron highly recommends that you purchase and understand two documents published by
SAE, which describe the recommended cables and connectors used for J1939 networks
(approximately $100). These documents (J1939-11 and J1939-15) provide important
information for cabling and connectors used to interconnect the J2K100 with the J1939
network. You can find these documents at the following web page:
http://www.sae.org/standardsdev/groundvehicle/j1939a.htm
Deutsch Industrial Products Division is a supplier of J1939 connectors; their catalog can be
found at the following link:
http://www.deutschipd.com/cans.pdf
4 Determining J1939 Network Type
Before installing Maretron’s J2K100, it is imperative to understand the type of J1939 network
you are dealing with, which may be one of the following:
1. Single Engine/Genset, No Existing J1939 Network
2. Single Engine/Genset, Single J1939 Network (Figure 2)
3. Two Engines/Gensets, No Existing J1939 Network
4. Two Engines/Gensets, Single J1939 Network (Figure 3)
5. Two Engines/Gensets, Dual J1939 Networks (Figure 4)
4.1 Single Engine/Genset, No Existing J1939 Network Installation
Although an engine or genset may have a J1939 interface, a particular installation may not
have an existing J1939 network because no other device is connected. In this case, it will be
necessary to build a J1939 network to interconnect the engine/genset with the Maretron