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[802.3af] RE: Classification currents range

Title: RE: Classification currents range

I assume you retracted the first mail with this Subject but you expect a reply to this one.

I have no objection to the slight "streaching" that you propose provided it it truly needed. Can anyone else support the need? Any problems introduced by the slightly higher currents?

We "voted in" the present values at some level. But that should not block this change if needed.

A couple of "typos" to consider changing in your proposal:

1.) You did not change page 16, line 44. I believe you'd want to also change to "0.5 mA to 8 mA".

2.) Your page 17, line 7 proposed chnage was "10 mA to 49 mA". I believe you mean "16 mA to 49 mA".

3.) You suggest Table 3 changes for "Class 5: 25 mA to 47 mA", and suggest "greater thna 49 mA being the invalid result". This leaves 47 to 48 mA undefined. This is perhaps OK but we might use "25 mA to 48 mA, with > 48 mA being the invalid result" and avoid this undefined window.


-----Original Message-----
From: Yair Darshan [mailto:YairD@xxxxxxxxxxxxxx]
Sent: Tuesday, August 21, 2001 1:27 PM
To: Stewart, Donald S (Don); 'R karam'; 'Rick Brooks'; 'Schwartz,
Peter'; 'Dave Dwelley'; 'Lynch, Brian'; 'bruce.inn@xxxxxxxxxx'; 'Steve
Carlson'; 'AvinoamL@xxxxxxxxxxxxxxxxx'
Cc: 'stds-802-3-pwrviamdi@xxxxxxxx'
Subject: Classification currents range


It seems that the gaps between currents specified for various classes
of PDs during the classification procedure are too small and may produce
a measurement accuracy issue.

I am suggesting to change in the draft the numbers as described below:

Table 7  page 16 lines 25-39:
     Class1   8 - 10 ma
     Class2  13 - 16 ma
     Class3  19 - 23 ma
     Class4  27 - 33 ma
     Class5  37 - 45 ma

Table 7  page 16 lines 41:  1mA to 49mA
Table 7  page 16 lines 46:  10mA to 49mA

Table 7  page 17 line 5:  0.5mA to 13mA
Table 7  page 17 line 7:  10mA to  49mA
Table 7  page 17 line 9:  0.5mA to 19mA
Table 7  page 17 line 11:  23mA to 49mA
Table 7  page 17 line 13:  0.5mA to 27mA
Table 7  page 17 line 15:  33mA to 49mA
Table 7  page 17 line 17:  0.5mA to 37mA
Table 7  page 17 line 18:  45mA to 49mA

According to the above, table 3 should be changed to:
(Measured current method)

Class 1: 6.5mA to 11.5mA
Class 2: 11.5mA to 17.5mA
Class 3: 17.5mA to 25mA
Class 4: 25mA to 35mA
Class 5: 35mA to 47mA

Greater than 49mA: Invalid result, not a PD.

And table 4:(measured voltage method)

Class 1:  5mA - 8mA             V< 15V
          10mA-13mA             V>20V
Class 2:  10mA - 13mA           V< 15V
          16mA-19mA             V>20V
Class 3:  16mA - 19mA           V< 15V
          23mA-27mA             V>20V
Class 4:  23mA - 27mA           V< 15V
          33mA-37mA             V>20V
Class 5:  33mA - 37mA           V< 15V
          45mA - 50mA           V>20V



Darshan Yair
Chief   Engineer
> PowerDsine Ltd.  -  Powering Converged Networks
> 1 Hanagar St., P.O. Box 7220
> Neve Ne'eman Industrial Zone
> Hod Hasharon 45421, Israel
Tel:  +972-9-775-5100, Ext. 210. Cell: +972-54-893019
Fax: +972-9-775-5150
> E-mail: <mailto:yaird@xxxxxxxxxxxxxx>.