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jaimin patel
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Impedance for FF Cable

12/28/2011 12:23 PM

how to measure impedance (capacitence & resistance) for field bus(FF) cable?
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lyn
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#1

Re: impedance for FF cable

12/28/2011 12:28 PM

I'd use a meter.

The Impedance Measurement Handbook
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BruceFlorida
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#2
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Re: impedance for FF cable

12/28/2011 6:30 PM

Good link. Thank you.

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lyn
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#3
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Re: impedance for FF cable

12/28/2011 6:43 PM

You're welcome.
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tonykuphaldt
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#4

Re: Impedance For FF Cable

12/28/2011 7:56 PM

Here's a video clip showing a simple way to measure the impedance of any cable by matching the cable's impedance with a potentiometer connected to the far end, until no signal reflections are detected by an oscilloscope:

http://www.youtube.com/watch?v=zrDxSM91Jcg

Once you've identified an impedance match (i.e. no more signal distortion due to reflection), just disconnect the pot from the cable's end, then measure it with an ohmmeter.

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PWSlack
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#5

Re: Impedance for FF Cable

12/29/2011 4:02 PM

Look it up in the cable manufacturer's data.

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