Re: [8023-POEP] [802.3] Interpretations received since March IEEE 802 Plenary meeting
David et al.
With specific regard to interpretation request 1-07/05;
Q1: I believe that the specification is clear and unambiguous with
regard to the need for isolation and the location of the isolation
barrier and as such requires no further action other than to state this
to the enquirer.
Q2: I find that this is a request for consultation for a particular
implementation, this should be returned as such.
Q3: Again, this is a request to interpret the standard in view of a
particular implementation, and appears to me to be a request for
consultation and as such should be returned.
Q4: Once again, consultation for a particular implementation and should
be returned.
All this aside, I believe that the standard is flawed because, while the
standard is complete and unclear, it is also quite unworkable. Section
33.4.1 which reads:
"The PSE shall provide electrical isolation between the
PI device circuits, including frame ground (if any), and
all PI leads."
asks for an isolation barrier where a DC path must clearly exist. The
specification for the PD,
"The PD shall provide electrical isolation between all
external conductors, including frame ground (if any),
and all PI leads."
is much more appropriate. As you pointed out and was discussed at this
week's PoE Plus interim, we need to address this and repair the standard
as soon as practical. I will plan to make time available during the PoE
Plus meetings during the plenary week to address this issue that goes
well beyond the limited scope of an interpretation meeting.
Cheers
Mike
Michael McCormack
Texas Instruments, Power Interface Products
50 Phillippe Cote St.
Manchester, NH 03101 USA
Voice: +1 603 222 8686
Fax: +1 603 222 8580
Email: mike_mccormack@xxxxxx
Web Site: http://www.ti.com
-----Original Message-----
From: owner-stds-802-3@xxxxxxxxxxxxxxxxx
[mailto:owner-stds-802-3@xxxxxxxxxxxxxxxxx] On Behalf Of David Law
Sent: Monday, May 23, 2005 5:05 AM
To: STDS-802-3@xxxxxxxxxxxxxxxxx
Subject: [802.3] Interpretations received since March IEEE 802 Plenary
meeting
All,
Just to inform you that IEEE 802.3 has already received three
interpretation requests since the March Plenary meeting. These requests
are:-
Subject: PME Aggregation restrictions
Reference: 3-07/05
Request URL: http://www.ieee802.org/3/interp/interp-3-0705.pdf
Subject: Auto-Negotiation
Reference: 2-07/05
Request URL: http://www.ieee802.org/3/interp/interp-2-0705.pdf
Subject: DTE Power via MDI Isolation
Reference: 1-07/05
Request URL: http://www.ieee802.org/3/interp/interp-1-0705.pdf
These requests, along with any others we receive, will be considered
during an Interpretations Ad Hoc meeting at the July IEEE P802 plenary
meeting and I will provide a further update nearer that time with the
final list of Interpretations requests to be considered.
The IEEE P802.3 Working Group process for the generation of an
Interpretations response is documented in Clause 6,
'Inquiries/Interpretations' [URL -
http://www.ieee802.org/3/rules/P802_3_rules.pdf#Page=13&view=FitH,500]
of
the IEEE 802.3 Working Group rules.
Regards,
David Law
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