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Sniffing a bidirectional line — Parallax Forums

Sniffing a bidirectional line

mojorizingmojorizing Posts: 249
edited 2008-07-09 02:08 in General Discussion
I'm intercepting the "K" line on a OBDI automobile scanner (ISO-9141:1989) . I'm somewhat familiar with the protocol but would like to know if there's a technique or hardware that would help in distinguishing what the direction of the pulses are coming from, without actually tapping into the scanner's I/O circuit.

Thanks, Kevin scool.gif

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Comments

  • steve_bsteve_b Posts: 1,563
    edited 2008-07-09 02:08
    I suppose you could use an oscilloscope and put a probe at each end of the wire....the probe that gets the pulse first is probably where it's coming from...having said that, if you find the end of the wire to put a probe on it, you probably know what it is and that it's coming from there!

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    <FONT>Steve



    What's the best thing to do in a lightning storm? "take a one iron out the bag and hold it straight up above your head, even God cant hit a one iron!"
    Lee Travino after the second time being hit by lightning!
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