What source address should the NI9862 CAN module use when sending j1939 messages?

[wbarrer]

I am trying to develop an application that will write to and read from off road vehicle ECUs. I have the NI9862 CAN module and XNET drivers. I can read data from an ECU. I can write frames to the CAN bus but the ECU under test doesn't appear to read the message. I get no ACK bit, and the ECU in question (an instrument cluster) does not change it's messages in anyway, nor do the gauges or telltales change.

Complicating this is the fact that the ECU is "Brand X " and it's PGNs are proprietary. I've tried sending the PGN inquiry message (PGN59904) but get no response from the ECU. I've been using 255 (global) as my source address.

Is there a particular source address for the NI9862 in J1939?

Thanks

[Bob_Y. · Accepted solution]

There is no particular source address for the NI9862. It can be used to simulate any of the 256 available addresses. If you are trying to simulate an off-board test tool, that usually has an address of 0xFA.

I am afraid that if you don't know any of the PGNs that it expects or any of the addresses that it expects to see them on, you will have a very difficult time getting it to work. 

Good luck,

Bob Young

[wbarrer]

Thanks for the tip.

Your point about the difficulty of doing this not knowing the PGNs is well taken. I do know the range of the PGNs values that I need, I just don't know the particulars of the PGNs.  I am getting two alternating frames from the cluster and a third frame every 20 frames. The PGNs are 65282, 65330,(alternating)  and 65333 (every 20 frames). I  change the data bytes in 65330 and 65282 by pulling some inputs high and using a pot to simulate an accelerator pedal.

Hopefully though trial and error and more web surfing I can figure these out.

Walt Barrer

Electrical Engineer

Instrument Sales and Service Inc.