So you are saying that an emission limit was imposed to improve immunity of the self-same equipment? I have to go on record disagreeing with that interpretation. As for protection of nearby circuits, my guess is that if you calculate coupling from a cable just meeting your telecom port CE limit to an adjacent cable, you will find that even common mode coupling is orders of magnitude below the intentional signal carried in the adjacent victim cable. I say this in full ignorance of just what that CE limit is, since I know that a CE limit designed to protect against rfi will more than protect against cable-to-cable coupling.
---------- >From: [email protected] >To: [email protected], [email protected], [email protected] >Cc: [email protected] >Subject: RE: R: Conducted Emissions on Telecom Ports >Date: Thu, Sep 7, 2000, 5:01 PM > > Actually it's to reduce interference to one's own equipment, (if it emits it > - it's also susceptible to it). It also has the effect of reducing > interference to other near by equipment. > > > Michael Sundstrom > Nokia Mobile Phones, PCC > EMC Technician > cube 4E : 390B > phone: 972-374-1462 > mobile: 817-917-5021 > [email protected] > amateur call: KB5UKT > > > -----Original Message----- > From: EXT Ken Javor [mailto:[email protected]] > Sent: Thursday, September 07, 2000 11:43 AM > To: Paolo Roncone; '[email protected]' > Cc: '[email protected]' > Subject: Re: R: Conducted Emissions on Telecom Ports > > > > Although I don't work commercial EMC on a regular basis and I do not know > over what frequency range the telecom port CE are controlled (I assume here > 150 kHz - 30 MHz), I believe that there is a mistaken premise inherent in > the comments to which I am responding. The purpose of controlling common > mode CE on any port is not to protect equipment at the other end of the > cable, or other co-sited cables, but rather to control radiated emissions in > a frequency range in which CE are easier to measure than RE. In turn, the > purpose of controlling RE is to protect broadcast radio reception. > ---------- >>From: Paolo Roncone <[email protected]> >>To: "'[email protected]'" <[email protected]> >>Cc: "'[email protected]'" <[email protected]> >>Subject: R: Conducted Emissions on Telecom Ports >>Date: Thu, Sep 7, 2000, 9:45 AM >> > >> >> 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: [email protected] [SMTP:[email protected]] >> Inviato: mercoledì 6 settembre 2000 17.55 >> A: [email protected] >> 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" <[email protected]> >> >> To: "Pryor McGinnis" <[email protected]> >> cc: [email protected], [email protected], >> [email protected], "John Moore" >> <[email protected]> (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" <[email protected]> on 05/09/2000 20:54:51 >> >> Please respond to "Pryor McGinnis" <[email protected]> >> >> Sent by: "Pryor McGinnis" <[email protected]> >> >> >> To: [email protected], [email protected], >> [email protected] >> 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: <[email protected]> >> To: <[email protected]>; <[email protected]> >> 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:[email protected]> 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:[email protected]] >>> Sent: Thursday, August 31, 2000 6:24 AM >>> To: Pettit, Ghery; [email protected]; [email protected] >>> Subject: Re: Conducted Emissions on Telecom Ports >>> >>> >>> >>> Confusing isn't? >>> >>> ----- Original Message ----- >>> From: Pettit, Ghery <[email protected]> >>> To: <[email protected]>; <[email protected]>; <[email protected]> >>> 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: [email protected] [mailto:[email protected]] >>> > Sent: Wednesday, August 30, 2000 2:04 PM >>> > To: [email protected]; [email protected] >>> > 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:[email protected]> 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:[email protected]] >>> > > 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 >>> > > [email protected] <mailto:[email protected]> >>> > > 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: >> [email protected] >> with the single line: >> unsubscribe emc-pstc >> >> For help, send mail to the list administrators: >> Jim Bacher: [email protected] >> Michael Garretson: [email protected] >> >> For policy questions, send mail to: >> Richard Nute: [email protected] >> >> >> ------------------------------------------- >> This message is from the IEEE EMC Society Product Safety >> Technical Committee emc-pstc discussion list. >> >> To cancel your subscription, send mail to: >> [email protected] >> with the single line: >> unsubscribe emc-pstc >> >> For help, send mail to the list administrators: >> Jim Bacher: [email protected] >> Michael Garretson: [email protected] >> >> For policy questions, send mail to: >> Richard Nute: [email protected] >> >> > > ------------------------------------------- > This message is from the IEEE EMC Society Product Safety > Technical Committee emc-pstc discussion list. > > To cancel your subscription, send mail to: > [email protected] > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Jim Bacher: [email protected] > Michael Garretson: [email protected] > > For policy questions, send mail to: > Richard Nute: [email protected] > ------------------------------------------- This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. To cancel your subscription, send mail to: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Jim Bacher: [email protected] Michael Garretson: [email protected] For policy questions, send mail to: Richard Nute: [email protected]
