J1939 DBC importation: multiplexor issue

Richard Gagnardot 2 years ago in IQANdesign updated by Gustav Widén (System support) 2 years ago 9


I have imported a J1939 message with a multiplexor starting on bit 13. I was used to have 1  message by multiplexor value (in my previous importations)  but I only have 1 message with the data of the last multiplexor value. Nevertheless, the Multiplexor seems to be detected:

Image 2994

Under review

If you select the parameter group and import all parameters, it should create multiple JFIN channels, one for each page value in the DBC. Does that work?

Hello Gustav, 

No, it only import 1 message with all parameters even if it detect that 2 parameters on "page" 3 only. Here is a screenshot of the JFOUT channel imported.

It looks like only some of the parameters have a page set. I wonder if that could be part of the explanation.

Here is an example with a DBC I created from IQANdesign, 

When importing this one it generates one JFOUT for each page.


J1939 test page not first.dbc

Is it possible you can share the DBC you are having problems with? If you do not want to post it here, you can always go via your local Parker rep. 

Ok, via the local Parker rep, but I dont find how to do it?

If you do not know the Parker account manager or regional applications engineer for electronics, I am guessing it could be that your company is buying through a distributor. They in turn will have contact names. 

I just found the "drop us a file" in the menu. The file is loaded: 

Thank you.

I checked the file in Vector CANdb++

The multiplexed signals that got imported to IQANdesign are those where you have a fixed value in the property for Muliplexor/Group. 

There is also a signal that has a range (0-2) set on Muliplexor/Group, this is the signal that did not get imported.

If you manually edit your DBC to have a fixed value on this property, the IQANdesign import will generate a second JFOUT.

For the values given as a range, is the expectation to have one JFOUT for each value, even though all parmeter outs in these channels will be identical? 


Ok, understood. What I meant was that I have 2 solutions: reduce the number of pages or rename the parameter with the range 0-2 to have one parameter for each multiplexed value.

For the values given as a range, since the message would have exactly the same bit order, it is not a big deal for me to only have 1 message for the whole range. 

Thanks for your help.


IQANdesign 6.08.24 fixes a problem with creating JFOUT for multiplexed signals.

56972DBC problems with paged protocol
Only one JFOUT was added for paged protocol. Fixed