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Re: [8023-POEP] 2P v 4P and safety



Title:
I believe the standard should approach this, but state that one cannot put 2P to one PD and another 2P to a second PD. This starts to make things much more complex. If anything, have a PD that splits the power to the two devices individually. We need to set some limits in our efforts or this can go on for years as others will start to find mini loop-holes to work with.
Derek


Geoff Thompson wrote:
Yair-

My opinion is that the question below needs to be a formal decision of the group in session. We should put the question on the agenda of "issues" for July.

Geoff

At 12:40 AM 6/8/2005 , Yair Darshan wrote:

Hi Geoff

Thanks for the reply.

Yes, I understand that it is no law issue. When I use "legal" I meant conformance to the relevant standards.

According to your last conclusion, I understand that splitting 4 pair cable to 2 outlets (each outlet gets 2 pairs) is valid scenario which PoEp has to address too.

Now we will have the following PD options:

High Power 4P PD

Or two High Power 2P PD's

Or two IEEE802.3af PDs

Do we really want detect and power all options or we wish to detect and power only 4P or 2P high power or single IEEE802.3af PD and only prevent damage to two IEEE802.3af PDs connected to the same cable and leave the decision if to power it or not to the system (implementation specific etc?).

Yair 
 

From: Geoff Thompson [mailto:gthompso@xxxxxxxxxx]
Sent: Tuesday, June 07, 2005 6:56 AM
To: Yair Darshan
Cc: Geoff Thompson; STDS-802-3-POEP@xxxxxxxxxxxxxxxxx
Subject: RE: [8023-POEP] 2P v 4P and safety [Unscannable attachment] [Unscannable attachment]


Yair-

"legal" vs. common...

There is no matter of law involved, only conformance with voluntary standards.

If you insert a splitter into a single outlet then there is no conformance issue.
If you split a cable to 2 outlets you are not conformant with TIA-568. The US has always "required" that you run a single 4-pair cable to each RJ-45.

The International Standard, ISO/IEC 11801 does not require this. It was an international fight of long standing. The German national body and a major international connector manufacturer (US headquartered) bitterly opposed mandating 4 pair per outlet. Therefore, 2 pair is allowed.

I hope this helps.

Geoff

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