MD4-7 loss of contact with MC43 issue

george zalesski 5 months ago in IQANdesign updated by Gustav Widén (System support) 5 months ago 6

Hi,  I have a system were I have a MD4-7 and MC43 in the system.  Occasionally  the MD4 starts displaying every second a loss of contact with MC43.  i can see this being logged as well.  the MC43 seem ok, no loss of contact with MD4.   also I have checked the BUS, no errors no frame errors.  all I can see that every time this MSG pops up the 0EF00  84->83  message stops, when the CAN message restarts the MD4 pop up message disappears.  any help would be appreciated.

Image 4171


No contact with another master in a multimaster system is from the Diagnostics bus.

What is the Diagnostics bus J1939 start address set to in the system? 

Looking at the cutout from the trace, I would guess it is on 130 (0x82) Then from the symptom, I guess you can also see a gap in the PDU1 message from 0x84 to 0x82. 

Is the MC43 very busy with short cycle time and high cycle utilization? 

SW version? 


I'm running the MC43 and MD4 at 50msec frame rate, but the code is light total utilization is <5%.

Yes I have the Start Adress set to 130.

The project is built with

did not see issues with 84 -> 82 messages, Just the 84 to 83.

Is the Diagnostics bus on one of the buses CAN-C or CAN-D? 

Version 6.08.25 is before the updates needed for reliable operation on the new CAN-C and CAN-D hardware, see Release notes - IQANdesign 6


Symptoms match problem in  firmware for CAN-C/D co-processor on newer MD4 modules. 

Can be fixed by upgrading to IQANdesign 6.08.28 or newer, see Release notes - IQANdesign 6. Also see PCN.