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Diagnostic Bus with Generic Bus

ksilovich 2 years ago in IQANdesign updated by Steven Hechtman 1 year ago 3

Question 1:

Now that we can put a Generic Can Bus on a J1939 Bus,  Is there any reason we cannot support a Generic Bus with a Diagnostic Bus.   If I try to do this, I get an error.   


I know of this work around, but it seems like alot of work, since the principles are in place to support this on any bus that is not connected to the Diag. 

https://forum.iqan.se/communities/1/topics/1110-j1939-generic-on-the-same-bus

Image 3689

Question 2:

Is there any way to support 500k on the Diag bus.   This project I am working on, we are not using the Diag bus at all.  But we need (2) 500k busses. We are using the MC41 for Can Bus communication only, and 2 outputs for a relay.  So doubling the cost for an MC42 is out of the scope of this project and we would have to try to source an alternative controller, which I rather not do. 

Right now we are using (100/year) MC41's on a sister project to this one  (which just started this month), and this project would add an addition 150/year starting next year. 

If I have to source a different controller, then all 250 trucks starting Jan 1st of 2024 will be moving away from the MC41.   Would love for some feedback, so I can start making plans of what we need to do for these 2 projects. 


1) Unfortunately, we won't be able to support the Diagnostic Bus and Generic Bus on the same CAN port. The purpose of this is the use of generic CAN is blocking diagnostic traffic to avoid arbitration errors and other problems if an application were to use the same CAN identifiers as the IQAN PC tool. 
2) There are plans to support more baud rates for the diagnostic bus but no firm timeline as of yet when that will happen. 

Is it possible to move your ECU's over to one CAN port and keep the diagnostic bus separate? 

2) Supporting 500kbps for the diagnostic bus would be a very valuable feature, as many vendors and OEMs move away from 250kbps busses. With support for only 250kbps on the diag bus, this makes a CAN channel useless on many applications. Thank you for your feedback on this!

1) For new designs like this were we have full control of the CAN id's that would be used.  Could you not allow us to used generic can with the limitation of x, y, and z ID can not be used and throw a fault when you try to use one of the pc can id's? 

2) do you think this is a revision update. Or would it be in iqan 7 down the road by years? 

Unfortunately I cannot, reason I'm asking these questions.  Can port B is almost fully utilized, as there are about 10 other modules on that bus.  And port A will have 3 of its own modules for what we are supplying this customer.