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Fixed

MD4-7 Blue Screen

ksilovich 3 years ago in IQANdesign updated by Ulrik Zakariasson (Software development) 3 years ago 3

I am getting a blue screen on a program I wrote with IQAN 5 and an MD4-7. 

The program starts and functions normally and then 10 seconds after start up I get this screen.

 

Under review

What do you have connected to the MD4 when this occurs? The picture looks like it is on the bench, but I am guessing there might be some CAN nodes connected to it also there. 

I see two possible reasons.


If you have some of the other CAN nodes connected to it:
Have you made some estimate on the amount of outgoing traffic on the CAN buses, to see if you have time to send the CAN frames with the transmit rate you set?

If the physical installation on CAN is correct but the MD4 tries to send too many messages, this results in a buildup of messages on queue, and when this reaches a certain level one of the checks related to the RTOS kicks in and stops the MD4 (safe state), the bluescreen is then shown with some debugging information. 


For example, if you have a 250kbps bus and there are 15 full-length CAN frames sent with a 10 ms repetition rate, each CAN frame would need about 0.7 ms to transmit on the bus, and time it would take to send all would be 10.5 ms. This would result in a theoretical bus utilzation > 100%, which does not work.



If the MD4 is showing this symptom when nothing is connected:

Do you have CAN-C in the MD4 set to Terminate=No ? 

In version 5.00, there is a problem with how wiring errors on CAN-C/D are handled. A problem like short to ground or an un-terminated CAN bus may instead of the expected CAN critical error result in a buildup of outgoing messages. This would then result in the same error as mentioned above. 

The problem with the MD4 handling of CAN-C/D errors is solved in 5.01. Version 5.01 is scheduled for release in early November.

I have the last case issue.   I was bench testing the program, and I am using CAN C, but it was not connected to a CAN network.   Sounds like you already have a solution for it.  Thank you.