Multi master j1939

christophe 7 years ago in IQANdesign updated by Gustav Widén (System support) 7 years ago 6


i need to comunnicate lots of i/o's between 2 master modules. Cant get this working with j1939 protocol.
Where can i find more information?
I've already studied the example Multimaster JFOUT file.

Satisfaction mark by christophe 7 years ago

Hello Christophe.

If you follow the example it should work.

Have you set the correct Source address for your masters?

Yes i have.

I cant figure out why even the example in the solutions libary doenst work.
I assume that if i set the digital input to true that the output becomes true in the Multimaster Jfout example.

Tried this with Iqan simulate.

The red circeled True changes rapidly from true to false.

Thanks for your time!

Hello Christophe.

Ok, i see.

You can not use the simulator to check if J1939 traffic works.

It will not change the input automatically when you change the output.

This is because it is normally traffic that comes from outside the IQAN system and that we don't have any controll over that is sent. You can change the values for the inputs manually the same way as you do the outputs.

The channel that you circled that is True is just the simulator assuming that your J1939 connection works.

It can be set either OK or Timeout, and the J1939 modules can be set to OK or No contact. This is to be able to simulate errors and see how your application behaves in those cases.

Have you tested to download your application to the masters?

Ah that explains a lot!
Havent tested because we're waiting for hardware parts. This is our first Iqan project.

Thanks for your time!

To build up simulation of the full system, the simulation example file for multi master JFOUT shows how the JPIN channels can be controlled in simulation by the JPOUT channels. See the file "Multi master JFOUT.isa4" in the solutions library folder.

As Thomas wrote, this won't simulate the CAN bus traffic. But it will help when simulating the logic of the complete application.