Has anyone seen problems with ethernet and conducted emissions? I have a home office with 4 PCs networked with ethernet running over UTP and I haven't seen much of a problem. Granted, the longest cable run I have is to a file server in the basement (about 10 meters) but both my AM radio and my shortwave set seem to work just fine. The only thing I remember picking up is 20MHz on the shortwave set. (Most 10Mbit ethernet devices use a 20MHz clock.) At work we have both 10 and 100Mbit ethernet (150-200 nodes) and the AM reception is really bad but I attribute that to the building (big steel and brick box) more than noise as reception improves as you get closer to a window. I haven't tried the shortwave at work being that shortwave reception is usually bad during the day anyway.
As far as telephone lines are concerned my ears don't pick up much noise above 19kHz. I would think anything else would be covered by immunity standards. Steve -----Original Message----- From: Cortland Richmond [mailto:72146....@compuserve.com] Sent: Thursday, September 07, 2000 11:01 AM To: Paolo Roncone; ieee pstc list Subject: Re: R: Conducted Emissions on Telecom Ports Paolo Roncone wrote: >>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. I disagree. The purpose of emissions standards is to prevent interference. Some are to similar functions, some are to other media. There is no interface for interference at which point the manufacturer may say: "Interference when you use this isn't our problem." We may say: "Use shielded cable," or "Put a ferrite on your cable," but we can't evade the physical fact that it is our own equipment which is the source of interference, and the cable is its antenna. It does not matter that we do not own the cable; if you plug it in and there is interference, it is up to the people who made the equipment to see the interference reduced. There is no transfer of ownership for radio waves. Granted, to call a LAN cable telecommunications is a clumsy construction of the regulation. But those who grasp at that straw to save a few currency units will find themselves later regretting that they have done so. If you are beaten and robbed for a display of wealth, it is no use protesting that the money was counterfeit. Cortland Richmond (I speak for myself alone and not for my employer) ====================== Original Message Follows ==================== >> Date: 07-Sep-00 07:48:16 MsgID: 1072-46656 ToID: 72146,373 From: Paolo Roncone >INTERNET:paolo.ronc...@compuprint.it Subj: R: Conducted Emissions on Telecom Ports Chrg: $0.00 Imp: Norm Sens: Std Receipt: No Parts: 1 From: Paolo Roncone <paolo.ronc...@compuprint.it> Subject: R: Conducted Emissions on Telecom Ports List-Post: emc-pstc@listserv.ieee.org Date: Thu, 7 Sep 2000 16:45:03 +0200 Reply-To: Paolo Roncone <paolo.ronc...@compuprint.it> 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> > > > > > > ------------------------------------------- ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson: pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org **Primary Recipient: "'eric.lif...@ni.com'" INTERNET:eric.lif...@ni.com ====================== End of Original Message ===================== ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson: pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: majord...@ieee.org with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: jim_bac...@mail.monarch.com Michael Garretson: pstc_ad...@garretson.org For policy questions, send mail to: Richard Nute: ri...@ieee.org
