David, Where in article 3.6 of CISPR 22 is the term "multi-user" used? Also, please keep in mind that the ferrite clamps are used only for testing radiated emissions from table top EUTs. This telecom port conducted emissions issue (hence the need for article 3.6) is entirely separate.
Ghery From: david_ster...@ademco.com [mailto:david_ster...@ademco.com] Sent: Friday, January 31, 2003 5:35 AM To: ghery.pet...@intel.com; gary.mcintu...@worldwidepackets.com; richwo...@tycoint.com; emc-p...@majordomo.ieee.org Subject: RE: EN55022:1998 and telecom ports Ghery - Ethernet on coax (10Base2) is indeed multi-user. Calling Ethernet/FE on twisted pair 'multi-user' ignores the fact each cable conect two and only two units. Hub/switch ports receive the signal, then reconstitute the signal before re-transmitting to the next unit. With EN55022:1998 +A:2000's ferrites, STP CAT-5 ironically will look cleaner than UTP CAT-5, (ferrites attenuate PC-to-hub common mode). UTP has been repeatedly shown to radiate less than STP. In effect, spec writers 'stack the deck' in favor of STP. Hmmm. Earthing STP shields at both ends is potential safety hazard, but that is EN60950, not EN55022. David From: Pettit, Ghery [mailto:ghery.pet...@intel.com] Sent: Thursday, January 30, 2003 5:27 PM To: 'Gary McInturff'; Pettit, Ghery; richwo...@tycoint.com; emc-p...@majordomo.ieee.org Subject: RE: EN55022:1998 and telecom ports Gary, Unfortunately, Article 3.6 of CISPR 22:1997 states: "3.6 telecommunication ports Ports which are intended to be connected to telecommunication networks (e.g. public switched telecommunication networks, integrated services digital networks), local area networks (e.g. Ethernet, Token Ring) and similar networks." Ethernet is specifically called out as a telecommunication port in the definition. Rats! Ghery From: Gary McInturff [mailto:gary.mcintu...@worldwidepackets.com] Sent: Thursday, January 30, 2003 2:20 PM To: Pettit, Ghery; richwo...@tycoint.com; emc-p...@majordomo.ieee.org Subject: RE: EN55022:1998 and telecom ports Glad to hear this! Ethernet lines are interconnection of ITE components and not telecommunications cables. Asbestos shorts on - fire away. Gary From: Pettit, Ghery [mailto:ghery.pet...@intel.com] Sent: Thursday, January 30, 2003 10:45 AM To: 'richwo...@tycoint.com'; emc-p...@majordomo.ieee.org Subject: RE: EN55022:1998 and telecom ports Richard, Further clarification to this question was provided by the addition of the following note at the end of article 3.6 of CISPR 22:1997 as part of Amendment 2 which was published in October of last year. "NOTE A port generally intended for interconnection of components of an ITE system under test (e.g. RS-232, IEEE Standard 1284 (parallel printer), Universal Serial Bus (USB), IEEE Standard 1394 ("Fire Wire"), etc.) and used in accordance with its functional specifications (e.g. for the maximum length of cable connected to it), is not considered to be a telecommunications/network port under this definition." I haven't seen an EN version of this amendment yet, but CENELEC should be coming with it one of these days. You can purchase a copy of the entire amendment, which adds information on "multifunction equipment", from the IEC web page at http://www.iec.ch . Ghery Pettit Intel From: richwo...@tycoint.com [mailto:richwo...@tycoint.com] Sent: Thursday, January 30, 2003 10:32 AM To: emc-p...@majordomo.ieee.org Subject: EN55022:1998 and telecom ports EN55022:1998 defines telecommunication ports as " Ports which are intended to be connected to telecommunications networks (e.g. public switched telecommunication networks, integrated services digital networks), local area networks (e.g. Ethernet, token ring) and similar networks." Since "similar networks" are included, it would seem that dissimilar networks are excluded. What distinguishes a similar network to a dissimilar network? What are some examples of dissimilar networks that are not included? Richard Woods Sensormatic Electronics Tyco International This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc This message is from the IEEE EMC Society Product Safety Technical Committee emc-pstc discussion list. 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Visit our web site at: http://www.ewh.ieee.org/soc/emcs/pstc/ 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: Ron Pickard: emc-p...@hypercom.com Dave Heald: davehe...@attbi.com For policy questions, send mail to: Richard Nute: ri...@ieee.org Jim Bacher: j.bac...@ieee.org Archive is being moved, we will announce when it is back on-line. All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc