Generic CAN Frame Out - Assignment

Barnhart Crane 4 years ago in IQANdesign updated by Gustav Widén (System support) 2 years ago 4

I'm confused about the Generic CAN Frame Out channel. It appears it needs to be "assigned" to a certain module on the bus, but its very nature is that it 'belongs' to the IQAN master sending the frame out onto the bus. IQAN Design will not allow you to assign the channel to an IQAN module. It seems you can only assign it to a generic module.

Does a dummy module need to be created that represents the IQAN module? Or should the frame out channel be assigned to the module it's intended to be received by? This 2nd option doesn't quite make sense either, since a CAN frame could be intended for multiple nodes on the bus.

Any guidance?


You are correct, the channel is assigned to the module intended to receive it, that way the iQAN master knows which canbus to send it on. Of course nothing prevents other modules on the same bus from receiving the message.

Thanks Pierre! I guess it seems like assigning the channel to a bus would have made it more clear, but since this is the only time that concept is needed, maybe it wasn't worth introducing.

This was very helpful.

I agree with Barnhart, it would be much clearer if the message was to just get assigned to a CANbus in lieu of a specific controller on that CANbus. It makes me thing that the message will be sent with the destination address defined, even though the JFOUT message I am sending is in the PDU2 range and not intended for any singe node on this specific J1939 bus. Any plans to update this? I am using 6.08.

Yes, I agree that for broadcast messages it is quite confusing to have to assign the JFOUT (or GPOUT as in the original post) onto a specific module. 

The idea you are suggesting is actually quite similar to what we are looking at doing for making configuration of J1939 and Generic CAN more intuitive in an upcoming version.