Composite log - rendering error?

[Reverant]

I'm trying to track down a sync error in car that has a CAS with 24 "crank" teeth and 1 cam tooth.

The problem is that the log appears ok in some places, but in the next screen/frame it looks like multiple crank/cam signals are missing, accompanied by "compressed" teeth before and after.

Examples, normal screen:



Screen with (rendering?) error, that produces NO sync error. However I can't look/decide what the problem is when I get an actual sync error, when the log looks this:



I have attached the composite log.

Any ideas?

[jsmcortina]

I'd be interested to see a "Comm log debug" matching this data recording. The composite log as presented has numerous data points of 1048.575 which look like large gaps. That translates as 0xfffff in the raw data. This seems unlikely.

When trying to view the comp log in MLV I found that you can't click on the graph to highlight the raw data?? That works in TS.
At the weekend I was checking a comp log on a customer's engine and found it really tricky to zoom in on a false trigger - even though I'd highlighted that data, "zoom" isn't centred on it - so after each zoom you have to scroll left and right to try to find it again.

James

[Reverant]

1048575 is 2^20 - 1. Surely not a coincidence? I don't have a comm debug log for this composite log, but I can take one of Phil needs it to investigate further.

[jsmcortina]

I don't have a comm debug log for this composite log, but I can take one of Phil needs it to investigate further.

I think it would be helpful if you are able. Something is clearly wrong, but it it firmware or TunerStudio?

James

[Reverant]

I also tried with TS v2.6 and had the issue, so if it's TS issue, it has been there for some time. I haven't seen this on any other cars so far, just this one.

[Reverant]

New composite log with matching debug log, serial comms logging enabled.

[jsmcortina]

The cam rendering is odd in a few frames, but that crank 1048.575 weirdness isn't apparent in the log. The crank part is what I really wanted to see.

James

[Reverant]

What do you make out of the cam rendering? This car is randomly losing sync every now and then, and the rendering weirdness doesn't help at all in diagnosing the issue.

I can bring the customer in again tomorrow if you want me to replicate the weird crank rendering, but we probably need to fix the cam as well.

[jsmcortina]

What it looks like is the cam is getting noise pulses, those are causing the weird rendering. The rendering needs to be resolved though as it is confusing.

The cam is supposed to be triggering one edge, but every so often a trigger of the opposite polarity is sneaking through. The crank code automatically rejects these, but seems that the cam code is letting them through.

James

[Reverant]

What it looks like is the cam is getting noise pulses, those are causing the weird rendering. The rendering needs to be resolved though as it is confusing.

The cam is supposed to be triggering one edge, but every so often a trigger of the opposite polarity is sneaking through. The crank code automatically rejects these, but seems that the cam code is letting them through.

James

I'm pretty sure there are no additional cam pulses getting in, as I've watched the signals multiple times on the scope trying to resolve the sync loss (which is almost always a missing cam pulse). I can always re-verify that.