Hello Group, >From EMC emissions point of view, any cable connected to any device is prone to conducted emission problems. The is because grounding problems in a PCB exist or enclosure currents flow between shielded connectors. This leads to CM currents that will be measured.
The criterion for testing is if any cable gets that long that frequencies below 30 Mhz can get out : l > lambda/4 This requires cables to be longer than 2m50 at 30 Mhz to over 750 m at 150 KHz. This requirements is easily met by LAN and other ports. In the past no electrical equipment had any cable but the mains. The ITE equipment was recognized to have PSTN cables that long. Now antenna cables on Radio/TV gets the same treatment (and more) Cable television distribution system need conducted testing too. My opinion is that any "network" connection needs testing for Conducted emissions. In the case of the PC and the LAN card: definitely test. The attenuation of ground noise in any slot of the MB by the LAN card to the LAN cable, shielded or unshielded is unknown. In one MB it may pass, the other may fail. Regards, Gert Gremmen, (Ing) ce-test, qualified testing =============================================== Web presence http://www.cetest.nl CE-shop http://www.cetest.nl/ce_shop.htm /-/ Compliance testing is our core business /-/ =============================================== >>-----Original Message----- >>From: owner-emc-p...@ieee.org [mailto:owner-emc-p...@ieee.org]On Behalf >>Of Chris Allen >>Sent: Wednesday, September 06, 2000 10:40 AM >>To: Pryor McGinnis >>Cc: david_ster...@ademco.com; emc-p...@ieee.org; >>gary.mcintu...@worldwidepackets.com; John Moore >>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. >>> > > >>> > > 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 >>> > >>> > ------------------------------------------- >>> > 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 >>> >>> ------------------------------------------- >>> 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 >> >> >> >> >> >> >> >> >> >>------------------------------------------- >>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 >> >>
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