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Thread: Update rate : ODBLink MX+ & LinkECU

  1. #1
    Potential Tuner
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    Mar 2019
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    Update rate : ODBLink MX+ & LinkECU

    Hi!
    Newbie here to the forum.

    I have downloaded the TrackAddict app and really love the features. Thank you very much.

    I have a link G4+ ECU and I am doing my own tuning. I've tried TA for a couple of track days and the first time, I bought a cheap elm which was giving me very slow reading ( even in Torque) , now that I have purchase a MX+ , I am finding that my reading are all over the place. From 10hz to 2HZ to all the way down to sub hertz update. Track addict just cannot stabilize the speed. When using ODBLink, the update rate is fast and smooth.

    is sub 10Hz update rate normal or should I expect more ? I am not seeing any ODB2/CANBus errors on the ECU side.

    Thank you

  2. #2
    HPT Employee Weston@HPTuners's Avatar
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    Jul 2014
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    The OBD update rate will depend on which channels you've selected, how many of them you've selected, the vehicle's ECU, and of course the OBD interface device you are using. I've seen nearly 20 Hz in some cases, and as low as 1-2 Hz in others. Even on the same vehicle, I can get over 10 Hz easily, but then I select just a few more channels, and it's down to 3-5 Hz. That's just more or less the nature of polling SAE parameters, and we do use a few techniques to try to speed that up.

    A variable sampling rate may be caused by choosing data channels that don't need as frequent updates as others... For example, channels like barometer pressure or certain temperatures aren't going to change anywhere near as often or as much as engine rpm or throttle, so TrackAddict wont request the lower-priority data channels on every update. As such, you can see the sample rate increase at that time, and then go back down when it does an update that grabs all data channels. Overall, it's certainly faster than requesting all of the channels every time, but it does cause some variability in the reported sampling rate.

    Another possibility is that some ECU's respond to certain PIDs faster than others, and it's not always consistent, so you might have a channel selected that's slowing things down.

    And finally, it's also plausible that using the OBDLink app with an OBDLink device might be using their own accelerations, or at least different techniques than we do, and perhaps this particular ECU responds really well to that.

  3. #3
    Potential Tuner
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    Mar 2019
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    Thank you. I will check to see which one pid is guilty of slowing things down.