Author Topic: Hall Trigger dirak filtering  (Read 8689 times)

Offline AVP

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Hall Trigger dirak filtering
« on: March 26, 2011, 09:22:49 am »
With the latest vemstune version, i get a validation yellow alert for this feature saying that unless i need it, i do not have to have it on.

I do not get any trigger errors at the moment, so should this be disabled?
« Last Edit: March 26, 2011, 10:00:33 pm by mattias »

Offline mattias

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Re: Hall Trigger dirak filtering
« Reply #1 on: March 26, 2011, 10:02:21 pm »
It's only needed with noisy installs,  normally this is not needed.
Typically it was needed with some Toyota Supra installs where the old stock coils and wiring, in combination with high impedance VR/inductive sensors, caused a very bad combination.

Offline AVP

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Re: Hall Trigger dirak filtering
« Reply #2 on: March 26, 2011, 10:04:00 pm »
so disabling it wont cause any harm, right?

Offline mattias

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Re: Hall Trigger dirak filtering
« Reply #3 on: March 26, 2011, 10:12:24 pm »
Exactly.

You'll know if you need it.

Offline Ignitec

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Re: Hall Trigger dirak filtering
« Reply #4 on: March 28, 2011, 04:33:02 pm »
i've never seen hall that need it...
If you have everything under control, you\\\'re not fast enough!

Offline GintsK

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Re: Hall Trigger dirak filtering
« Reply #5 on: March 28, 2011, 08:52:50 pm »
It's only needed with noisy installs,  normally this is not needed.
Typically it was needed with some Toyota Supra installs where the old stock coils and wiring, in combination with high impedance VR/inductive sensors, caused a very bad combination.
Dirac is just for hall/optical sensors. Not for VR. As I understand it filter possible spikes during signal active edge.

Offline mattias

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Re: Hall Trigger dirak filtering
« Reply #6 on: March 28, 2011, 09:30:45 pm »
What I remember was probably what happened with Hall sensors on Supra stock harness, I know Jorgen had problems that created this feature:

Quote
# HALL dirac filtering. config12 bit7 and bit6

    * Highly experimental. Can filter very short spikes on HALL trigger input (usually from capacitive coupled noise from ignition wires - also depends on harness arrangement).
    * only enable it for low toothcount HALL trigger, if the pulse after the chosen edge is min 10 crankdegree long (or min 180 usec) and if you have mysterious trigger errors that you cannot get rid of, even with properly shielded trigger cable.
    * Must be disabled for VR trigger. Useless with VR trigger anyway (the LM1815 makes a constant pulse anyway if the signal goes below 0.0 V ... and that must not be filtered out for the trigger to work).
    * like for any VR, HALL-dirac filter must be disabled in both primtrig and sectrig with InputTrigger/ShortGapTrigger , InputTrigger/SubaruTrigger, (MembersPage/FiatStilo fiatstilo and subarutrigger).
    * config12=80 bit7=1 : HALL-dirac filtering for primary trigger
    * config12=40 bit6=1 : HALL-dirac filtering for secondary trigger (only very short pulses can be filtered on sectrig, even a 3-5 usec pulse might be accepted as a normal pulse)
    * config12=C0 HALL-dirac filtering for both trigger


Offline AVP

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Re: Hall Trigger dirak filtering
« Reply #7 on: March 28, 2011, 10:03:58 pm »
i see.
its turned off now!