Under review

MD4 blue screens

Adolfo 3 years ago in IQANdesign updated by Gustav Widén (System support) 3 years ago 7


We have a machine working from october 2020. it has a MD4-7:

On 7th June, the customer sent us this blue screen:

After switching off and on it has started perfectly. this is the MD4 log where we cannot see anything strange:

Shredder display master log (PY200046 - AC....irlx

Last week we received another feedback from another customer (working from may 2019) with this blue screen: 

Image 2811

By the moment, it has appeared just once. We hope this will not appear again.

But, if it possible, we would like to have any clue about waht can be the reason of those blue screens? We need to say somthing to our customers...

Thanks in advance,


Under review

This information on the screen indicate the MD4 has detected a type of error could be triggered by too much CAN traffic. 

It is interesting to know what the application cycle time and normal bus utilization is on the MD4 buses. 

As you say this machine has been operating for two years it cannot be as easy as the normal steady bus utilziation, if the problem is due to too much CAN traffic there must be a burst of messages. 

I am confused by the versions and the photo. The photo of the MD4 is showing it is running 5.04. 

The system log file is showing version 6.02. 

Did you get a photo of the machine that had 6.02 in it? For this type of error, it would have contained some more detail that could help in troubleshooting. 

Hello Gustav,

I am sorry, I see now that the first screenshoots of the machine working from october 2020 with the 6.02 version are missing in the post.

This is the MD4-7:

And this is the bule screen the customer sent us on 7th June:

Thank you for your prompt reply and best regards,


Thank you, this photo shows a different diagnostic, a watchdog reset. 

For a watchdog reset, the first thing I'd check is cycle utilization and application cycle time.

Hello Gustav,

Last week we were at one of those customers, the one with the V05 MD4.

The customer asked us about the occasional blue screen.

As you said that the problem would be due to " too much CAN traffic", we connected the computer and here you have the CAN usage:

In the moment we saved this screenshoot, all the nodes in the CAN were connected and communicating. I don't think that the traffic can be higher than the traffic in this image.

The most used CAN is the J1939, and, if I am right, it is near the middle of the maximum.

I hope this can help to get a better diagnosis.

Thanks for your help and best regards,


The expansion module buses will have a very stable bus utilization, and they appear to have plenty of margins. 

Traffic on J1939 buses tend to fluctuate more, but in this printscreen the gauge is not indicating that the bus utilization has peaked at a higher value. 

Any CAN related errors that showed up in the system log?

Shredder display master log.irlx

Here you have the system log.

I cannot see anything really strange on 29th october 2021, 13:35:06, the time which is showed in the blue screen error.

Just the usual J1939 error of some SPN we have programmed in the application, but not been received properly from the engine, open load errors because there were some missing devices...

The not contact error can cause the blue screen? Usually don't...

It will not be possible to see anything at the exact time of the bluescreen, when that type of critical error is detected everything stops, including the system log. 

But it is very interesting to see the types of errors that show up in the log before the bluescreen. 

If the No contact errors are due to modules that are actually missing from the bus, it will never have this type of effect. 

The No contact errors with G11 that come 6s after system startup looks like a 'normal' problem with a missing module. 

What is less likely but possible is that you could also have No contact errors if the bus is flooded with other CAN traffic, so one module is unable to deliver its messages on the bus on time. 

In this log the No contact errors with "Shredder radio control" are interesting, as they seem to appear during operation, and at one point a few minutes before the bluescreen. 

The steak of CAN related errors in July (including one CAN bus error July 21st) also look problematic. But since those are mainly on the expansion buses where bus load should be very predictable, I'd think that was more likely to have been caused by physical installation problems.