Hi Eric,
I 100% agree with you. The scope of emissions standard should be to protect the
"outside" (i.e. public) environment from interference. So only ports that
connect to public telecom networks should be covered by the standard. The
problem is (as pointed out in one of the previous notes) that the new CISPR22 /
EN55022 standard clearly includes LAN ports in the definition of
telecommunications ports (section 3.6) no matter if they connect to the
"outside world" or not.
Regards,
Paolo Roncone
Compuprint s.p.a.
Italy
-----Messaggio originale-----
Da: eric.lif...@ni.com [SMTP:eric.lif...@ni.com]
Inviato: mercoledì 6 settembre 2000 17.55
A: emc-p...@ieee.org
Oggetto: Re: Conducted Emissions on Telecom Ports
All,
As a not-quite-outside-observer (strictly EN 55011 here) of this thread, it's
not fun seeing LAN ports classified as telecom; IMO that's overkill for the
folks using EN 55022.
Up till now, I considered a port to be telecom only if it connects a client
facility to a carrier's network (DSL, ISDN, T1 and so on).
With repeaters every 5 meters, USB and 1394 can support a bus long enough to
connect between adjacent buildings. So, I wonder if some fanatic will soon be
promoting USB/1394 ports as telecom?
If Chris is right, and the EN 55022 version of the old telecom port conducted
emission standard was intended to protect other telecom signals in a bundle,
then I would think that this test is clearly redundant to the immunity tests
(61000-4-6 and -4-3) that offer the needed protection from the other end.
Does this emission requirement appear to be a waste of time and money to anyone
else?
Regards,
Eric Lifsey
Compliance Manager
National Instruments
Please respond to "Chris Allen" <chris_al...@eur.3com.com>
To: "Pryor McGinnis" <c...@prodigy.net>
cc: david_ster...@ademco.com, emc-p...@ieee.org,
gary.mcintu...@worldwidepackets.com, "John Moore"
<john_mo...@eur.3com.com> (bcc: Eric Lifsey/AUS/NIC)
Subject: Re: Conducted Emissions on Telecom Ports
Pryor,
Unfortunately, I don't think the definition is in question. It specifically
states, that for the purposes of the standard, LANs are to be considered as
telecomms ports as per section 3.6. It probably would have been less ambiguous
if the standard defined Telecomms ports as "Ports which are intended to be
connected to the telecomms network OR LANs OR similar networks.
As far as enforcement goes this will not change from the current method of
enforcing compliance, primarily via the end user requesting DoCs and the
relevent test data to back this document up.
I believe the requirement goes back to a test that was performed under either
VDE 0805 or 0806 (it was a long time ago that I had to perform the test). It was
specifically aimed at unscreened cables over a certain length being placed in
cable ducts and their impact on adjacent telecomms cables (if anybody remebers
StarLan this was the product I was involved in).
Chris.
"Pryor McGinnis" <c...@prodigy.net> on 05/09/2000 20:54:51
Please respond to "Pryor McGinnis" <c...@prodigy.net>
Sent by: "Pryor McGinnis" <c...@prodigy.net>
To: david_ster...@ademco.com, emc-p...@ieee.org,
gary.mcintu...@worldwidepackets.com
cc: (Chris Allen/GB/3Com)
Subject: Re: Conducted Emissions on Telecom Ports
I do not disagree with the positions posted on this subject. My question is
how does the EU interpret and enforce this requirement/definition.
Pryor
----- Original Message -----
From: <david_ster...@ademco.com>
To: <emc-p...@ieee.org>; <gary.mcintu...@worldwidepackets.com>
Sent: Tuesday, September 05, 2000 2:07 PM
Subject: RE: Conducted Emissions on Telecom Ports
>
> LAN ports
> Testing Conducted RF Emissions on LAN twisted-pair lines is almost
> contrary to the intent of EN 55022 as Gary pointed out. Conducted
> emissions is more appropriate for asynchronous analog lines.
>
> LAN transmissions are digital and synchronous (except maybe ATM); the
> receiver part of the interface circuitry locks onto the frequency of
> data, rejecting spurious frequencies. The signals are truely digital,
> not analog as in a modem.
>
> Arcnet, Ethernet, and Fast Ethernet TP cabling links two points
(node,
> hub, switch, bridge) which digitally reconstitute the signal,
> eliminating spurious cable frequencies.
>
> Token-Ring is peer-peer, usually through a passive hub. Each node
> (peer) reconstitutes the signal as above.
>
> Ethernet, F-E and Token-Ring ANSI/IEEE or ISO/IEC physical layer
> requirements define interfaces, cable lengths/type(s) and timing.
>
> Coax cable rules for Arcnet, 10Base2 Ethernet) permit connection to
> multiple nodes but again, the digital nature of the signals and the
> well-defined connectivity rules prevent problems.
>
> David
>
>
> ______________________________ Reply Separator
> _________________________________
> Subject: RE: Conducted Emissions on Telecom Ports
> Author: "Gary McInturff" <SMTP:gary.mcintu...@worldwidepackets.com> at
> ADEMCONET
> Date: 9/5/2000 10:54 AM
>
>
> Define telecom port.
> A LAN port isn't neccessarily a LAN port. Ethernet ports do not
> connect directly to the Telecommunications network - a necessary condition
> before being a telecommunications port. LANS and MANS operate all of the
> time without any use of any telecommunications equipment. Generally,
> Ethernet or Fast Ethernet for short distances and Gig Ethernet for longer
> distances. IF -- the telecommunications lines are needed there is some
sort
> of "bridge" that takes the ethernet and its digitized Voice over Internet
> Protocol (Voip) and does all of the phone stuff and makes the actual
> metallic connection. That "birdge" has the only telecommunication ports on
> it.
> Gary
>
>
> -----Original Message-----
> From: Pryor McGinnis [mailto:c...@prodigy.net]
> Sent: Thursday, August 31, 2000 6:24 AM
> To: Pettit, Ghery; david_ster...@ademco.com; emc-p...@ieee.org
> Subject: Re: Conducted Emissions on Telecom Ports
>
>
>
> Confusing isn't?
>
> ----- Original Message -----
> From: Pettit, Ghery <ghery.pet...@intel.com>
> To: <david_ster...@ademco.com>; <emc-p...@ieee.org>; <c...@prodigy.net>
> Sent: Wednesday, August 30, 2000 5:40 PM
> Subject: RE: Conducted Emissions on Telecom Ports
>
>
> > Actually, it's August 1, 2001 as posted in the OJ on January 25th of
this
> > year. You've got 1 less month to start testing to the new standard.
> >
> > Ghery Pettit
> > Intel
> >
> >
> > -----Original Message-----
> > From: david_ster...@ademco.com [mailto:david_ster...@ademco.com]
> > Sent: Wednesday, August 30, 2000 2:04 PM
> > To: emc-p...@ieee.org; c...@prodigy.net
> > Subject: RE: Conducted Emissions on Telecom Ports
> >
> >
> >
> > The date of withdrawal of EN 55022:1998 is September 1, 2001. Look
> at
> > the NIC manual's DofC --- the mfgr. may not be declaring compliance
> to
> > conducted emissions yet.
> >
> >
> > ______________________________ Reply Separator
> > _________________________________
> > Subject: Re: Conducted Emissions on Telecom Ports
> > Author: "Pryor McGinnis" <SMTP:c...@prodigy.net> at ADEMCONET
> > Date: 8/30/2000 10:31 AM
> >
> >
> > Hello All,
> >
> > The question originated from a manufacturer of LAN boards who sells to
end
>
> > users and to manufacturer's who integrate the LAN boards into end
> products.
> >
> > I advised the LAN board manufacturer that conducted emissions would be
> > required (with boards installed in typical host) on all LAN boards sold
to
>
> > end users and manufacturers of products that integrated LAN boards
should
> > test the ports for conducted emission in their end product. The LAN
board
>
> > manufacturer questioned double testing of the LAN boards. His concern
is
> > that boards that pass CE in a typical host may not pass in another
> > manufacturer's end product (rub of the green). The LAN Board
> manufacturer
> > ask for second opinions.
> >
> > Many thanks for your answers.
> >
> > Best Regards,
> > Pryor
> >
> > > -----Original Message-----
> > > From: Pryor McGinnis [SMTP:c...@prodigy.net]
> > > Sent: Tuesday, August 29, 2000 12:35 PM
> > > To: emc-pstc
> > > Subject: Conducted Emissions on Telecom Ports
> > >
> > > Below is a message from a non emc-pstc member.
> > >
> > > If a manufacturer purchases LAN boards which have been tested for
> > > conducted emissions in a host, is the manufacturer required to retest
> the
> > > LAN Ports for conducted emissions if the manufacturer sells his
product
> > with
> > > the LAN board installed?
> > >
> > > I am very interested in your comments.
> > >
> > >
> > > Best Regards,
> > > Pryor McGinnis
> > > c...@prodigy.net <mailto:c...@prodigy.net>
> > > www.ctl-lab.com <http://www.ctl-lab.com>
> > >
> > > -------------------------------------------
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