Review of trigger settings and trigger log

[dnb]

I have just turned on the cam trigger on my TVR (Rover V8 based) engine and hoped someone here could help me sanity check the configuration and check my understanding of the trigger log.

Both the config and trigger log are available here, along with the background of the cam trigger implementation:
http://www.vems.hu/wiki/index.php?page=MembersPage%2FDavidBlades%2FTrigTest

It looks like it works properly to me, but I am concerned there are missing trigger pulses in the trigger log for both primary and secondary triggers, but the engine didn't seem to notice...  Is this a feature of the trigger logging missing data?

All help gratefully received.

[VEMS]

Hello David,

Reviewed your triggerlog and indeed it seems to be missing some data, what works best is to take the triggerlog at engine cranking 8-10 seconds without IGN and INJ fuse.

Some background info:
When the rpm (or actually the amount of trigger events) surpasses what can be sent at current baud-rate the triggerlog is compacted to missing tooth and secondary only; at or around the switchpoint this can be confusing to look at. When taken at cranking rpm only there is enough time to send the un-compacted triggerlog, for diagnosis this is the most helpful.

Best regards, Dave

[dnb]

Thanks - very useful info and it makes more sense now.  I can try at a higher baud rate and keep the RPM low etc.

The last 18 cycles or so of the trigger log look to be complete and it shows the trigger pattern I was expecting, so I have based further config developments on this section since it all looks right as can be seen below:



This leaves me wondering how best to configure for the cam pulse at tooth 24 of the crank trigger.
My first attempt is here:
https://dl.dropboxusercontent.com/u/8968424/vems/v3.3_u004371-2014.07.05-01.22.04.vemscfg

[VEMS]

Hello David,

Your camsync configuration looks sensible, is your ignition phasing (in ign outputs visual) matches this, you should be to good to go.

Best regards, Dave

[dnb]

Thanks.  It would appear I was right first time with the phase.

[dnb]

I have a question to aid my understanding:

when a secondary trigger pulse occurs does the ECU immediately reset the trigger tooth array and restart counting from zero thus I should have the next cylinder in the sequence in set up in slot zero of the various H[n] tables or does the ECU wait until the next missing primary tooth before deciding to synchronise, meaning it would sync faster if H bin zero corresponded to the first cylinder after the missing primary tooth?

Thanks

[VEMS]

Hello David,

For missing tooth trigger there are several ways of jumping to sync (a bit to elaborate to outline quickly), but rest assured from 1.2.27 and up, the order of reftooth[n] or h[n] table does not matter, we sync to the right index on first transition from non-sync to sync. Startup speed with or without camsync is the same.

Best regards, Dave