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[Discuss] Wire tester (like a tone tester)

On Fri, Oct 3, 2014 at 10:28 AM, Chuck Anderson <cra at> wrote:
>> A DC voltmeter with RJ-45 modular plug on a pigtail should let you
>> check for PoE ?
> No, power won't be applied unless the PSE (power-sourcing equipment)
> detects a PD (powered device) at the far end.  A simple resistor
> should allow that to happen though.

So an RJ-45 pigtail for PoE testing with a VOM needs a 25 k? bleeder
in shunt (or in series on mA scale).
Good to know. Thanks.

(Alternatively, the periodic PSE DC pulse checking for new PD current
draw would be seen on an O-scope when setting up for TDR, or otherwise
detected with DSP sampling.)

Bill Ricker
bill.n1vux at

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