CAN connection between MD3 and MC31

Diogo Tasquin Reducino 1 year ago in Master modules / MD3 • updated by Gustav Widén (System support) 1 year ago 5

Hey there!

I'm using a MD3 and a MC31 on my application. I'm transfering the application through an USB-to-CAN interface (KVASER - LEAF LIGHT). I'm using the same cable to transfer the application simultaneously to MD3 and MC31. The transfer completes greatly, I can even use the Measure feature on IQANDesign to get signals from them both. But, between them, the MD3 can't see the MC31 (No contact error), as well as MC31 can't see the MD3. Can anyone help me? I can send pictures of the connection and the error that is occurring.

Satisfaction mark by Diogo Tasquin Reducino 1 year ago

A suggestion to start with is to check if the Diagnostics bus in the system layout is the same as what you have physically wired. 

Also, if you have a separate Master bus for APPOUT/APPIN, check if the wiring on this matches your application. 

The Diagnostics Bus is on CAN-C, but I haven't connected it phisically to anything. Also, the Master Bus between MC31 and MD3 (the two masters) is on CAN-A, and I've wired them propperly (CANL-A on MD3 to CANL-A on MC31 and CANH-A on MD3 to CANH-A on MC31) as I do when I connect the MD3 to an expansion module.

I have even transferred a simple application with one DIN on MC31 which activates a lamp on MD3 to see if there was something wrong with my earlier project, but it doesn't contact either.

I adapted my application to run on a XA-2 module and it works and communicates fine. Is there something else I can try to find the problem?


I assume you must have gotten the system up and running by now, but if not, and for anyone else reading this, I can clarify what I meant by checking the diagnostics bus. 

The diagnostics bus has to be connected in a multi-master system, this is where all the diagnostic CAN traffic between masters are sent. The master bus is optional, and used if there are APPOUT/APPIN channels sent.


Yes, I could get it running by connecting the diagnostics bus, my reseller told me it wasn't necessary so I did every thing I thought with the Master Bus and completely forgot the diagnostics. Thanks for get me thinking, sorry I didn't leave a reply earlier.