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Re: [802.3_4PPOE] PSE Unbalance Specifications

Hi David,

For ease of editing I would ask that we make sure baseline that touches these sections is aligned so I don't get editing conflicts. Likely Yair also has updates to this section, please merge this in where possible.
I also have comments (non-technical), feel free to merge these in so we can OBE them.

Then onto questions/comments:

- From the Figure I can see that Rload = Rch + RPair_PD.
Since this is the PSE unbalance requirement, why not merge these two resistors into one, call them Rload_min and _max. Their subcomponents are not relevant for this particular test.
I understand PClass_PD needs to be measured in between of these resistors, but we are getting stuck in the model here. Adjust the values of Rload_min and _max to compensate for the additional unbalance caused by R_pair_PD. This is a matter of computing the correct values.

- The seven step plan seems like something for the Annex.

- The requirement can pull in part of the plan:
"A PSE shall not source more than Icon-2P-unb on any pair when connected to a load drawing PClass_PD for a given Class, when connected through Rload_min and Rload_max, as shown in Figure X and Table Y."

- Finally I believe there should be margin between the PSE unbalance spec and the PD.
I suggest we have ICon-2P-unb for the PSE and -Con_PD-2P-unb for the PD.
Yair is looking into this if this allows us to simplify the requirements.

Kind regards,


From: David Stover <00000687aebafbf1-dmarc-request@xxxxxxxx>
Sent: Saturday, December 17, 2016 0:43
To: STDS-802-3-4PPOE@xxxxxxxxxxxxxxxxx
Subject: [802.3_4PPOE] PSE Unbalance Specifications

Hey all,

We've been hard at work preparing some baseline to address PSE unbalance requirements and test methods. In particular, we've tried to mimic PD unbalance baseline regarding what is specified in Clause 33 and what is specified in an informative annex.

Please consider and share your thoughts about this proposed baseline.

I've also included a PDF roughly detailing the markup from D2.2. Please be aware that a lot of this text was moved, not deleted, but Word has its own opinion about tracked changes sometimes...

David Stover II