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RE: detecting a PD disconnection event

Title: RE: detecting a PD disconnection event

there are a few comments below.
In general, I am making this proposal so that the 802.3af spec will not run directly against
an existing patent not matter how fond we are of DC minimum current.
I am not judging the patent at all, except to comment that it appears to have
some validity pertaining to UTP data networks. It would be unwise to ignore it.
If anyone can find prior art, then great. In the meantime we cannot and should not discuss any legal
or patent validity issues. I suggest we simply consider the alternatives in case we must use them.

The sole reason to detect an unplug is to shut down power so that other RJ-45 devices will not
be damaged. Therefore, we could allow a few different detection methods for an unplug event and still meet this goal.

That sounds good to me. The definition would be that the maximum time from an "unplug" action
until the PSE out goes to 5V or below is 400ms. Of course, we all need to discuss these  numbers.

These are good points.

The possible use of something like synchronous detection could help here.

This means that the PD would have a small circuit that produces a periodic current modulation.
The PSE has a watchdog timer that must always see the periodic current or the power shuts off.

I am assuming that this is independent of discovery, a different mechanism, and therefore not related
to false discovery.