Michael Carlyle 5 years ago updated by Gustav Widén (System support) 5 years ago 5
We are having trouble with Blue Screen Problems with Iqan MD4 when running 3.16 and higher (ever since the cycle time was allowed to be lowered below 25 ms). Running the cycle time higher decreases the occurrence rate. They occur mostly at startup so it is impossible to graph the system utilization.

It did not seem to happen in 3.14.

I have tried updating to 3.18 as there seemed to be some fixes for Blue screen problems but it is still happening.
I have received information about similar symptoms, MD4 bluescreen, in a couple of other applications too. Your observation that it seems to have come when minimum cycle time for the MD4 was dropped to 10 ms in 3.16 matches what I have seen on those other applications, but I am not sure. It has been seen on versions 3.16, 3.17 and 3.18.

The symptom is a bluescreen, and on there it is a name of a driver and the text “HB warning low”. It indicates that one software driver has not deliverd heartbeat on time, so the safety monitoring kicks in and stops the MD4. Afterwards, you may also find this “HB warning low” in the system log.

We are working on solving this for 3.19, but so far we have not been able to reproduce the issue with a realistically sized application. What we have seen during testing of 3.19 is that a high utilization test application that bluesceen in 3.18 will continue to operate without problem in 3.19, so the fixes we are working on look promising.

I got pic from a unti that had these in the MD4 system log which I think are associated with the Blue Screens:

adcdriver has HB WAR
candriver0 has HB WAR
spidriver1 has HB WAR

When will 3.19 be released? The BETA worked well at half the cycle time.