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[802.3_4PPOE] Summary of the missing requirements for Transients for <=30uS



Hi all,

After seeing all the responses, I propose the following remedy to my comment below.

 

The concept is to make it similar to what we have in clause 33 which is no PSE requirements for transients below 30usec

Make the following changes:

"Transients less than 30 μs in duration may cause the voltage at the PI to fall below VTran-2P. Requirements for Transients less than 30 μs in duration are not specified. See 145.3.8.6 for PD transient requirements."

 

Other option is to delete “"Transients less than 30 μs in duration may cause the voltage at the PI to fall below VTran-2P.” however I see the value with keeping this text but to complete explicitly the needed requirements which is in this case “no requirements are specified”.

 

Yair

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In clause 145 in the PD side we have clear requirements for what to do below 30usec and what to do between 30-250usec.

In the PSE side, it is only clear what to do between 30usec to 250usec.

Below 30usec the spec just giving us the info that the voltage can be lower than Vtran-2P but doesnt say what to do in this case.

If for example we didn’t have this text "Transients less than 30 μs in duration may cause the voltage at the PI to fall below VTran-2P” as we don’t have in clause 33, that it will not be raising the question OK so what netx? What is the requirement from PSE in that case. Should we keep the power? Should we remove power? We dont care? Or It is system decision? (i.e. may or may not remove power or “no requirements are specified” ? This is the problem that I am trying to resolve.

 

Yair


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