David -- how are you coupling into the signal line?? The diagram shows the 0.5uF capacitor in series with a 40 ohm resistor -- are you using these values??
If I'm doing the math correctly, a 20mH coil has an impedance of about 12.5k ohms at 100kHz (2 x 3.14159 x 100kHz x 20mH), and about 370 ohms at 3kHz. If your signal line is balanced, there will be a choke in each line effectively doubling the impedance to the signal. Seems to me you won't get much signal through at any data rate over a few kHz. What am I missing?? The experiments we've done here show that the only way to get to 100kHz is to use resistors in place of the chokes and clamping protectors on the input side. (Chokes alone won't protect the input side from seeing a large surge voltage.) Additionally, most data lines won't tolerate the .5uF capacitor in series with the 40 ohms (and then the 2 ohms source impedance of the generator). That 42 ohms back into the generator places an effective load on the data line of 42 ohms to ground AFTER the 20mH chokes, forming a voltage divider of about 300:1. In our 100kHz version, we use arrestor coupling to minimize the capacitance hanging on the line. As a manufacturer, we make a coupler that incorporates both methods described above -- 20mH chokes and 0.5uF capacitor -- good to about 3kHz, plus the arrestor coupling with resistors -- good to about 100kHz. Best Regards, Mike Hopkins -----Original Message----- From: [email protected] [mailto:[email protected]] Sent: Friday, March 29, 2002 8:54 AM To: [email protected]; [email protected] Cc: [email protected] Subject: RE: EMC test set-up for device with ethernet connection Ari, Circuit diagram is EN61000-4-5: Figure 10. My coil was 20mH coil: www.wilcocorp.com P/N HFT-203 which has a DC resistance, R(L), of 2 ohms. The key is minimizing R(L). Ethernet incorporates internal threshold-detection and noise-rejection; low level signals are rejected both devices on the link. Twisted-Pair Ethernet is transformer-isolated at each end to eliminate DC; signal is inherently limited due to 100-ohm source impedence. David -----Original Message----- From: [email protected] [mailto:[email protected]] Sent: Thursday, March 28, 2002 2:26 AM To: [email protected] Cc: [email protected] Subject: RE: EMC test set-up for device with ethernet connection David, if you have a decoupling circuit that keeps the surge away but passes ethernet, how about posting the details here? Lots of us would be most interested! Ari > -----Original Message----- > From: ext [email protected] [mailto:[email protected]] > Sent: 27 March, 2002 22:20 > To: [email protected] > Cc: [email protected] > Subject: RE: EMC test set-up for device with ethernet connection > > > > Richard, > > We made our own decoupler with low-resistance 20mH coils. > You really should > have an active link during conditioning. Off-line surge will > not detect a > partitioned port; if there is no link, there can be no > partition. A slow > link is better than no link. > > David > > -----Original Message----- > From: [email protected] [mailto:[email protected]] > Sent: Wednesday, March 27, 2002 12:55 PM > To: [email protected] > Subject: RE: EMC test set-up for device with ethernet connection > > > > You will not be able to transfer data when the decoupling > network is added > for the I/O surge test per EN61000-4-5. The data rate through > the decoupler > is very low. However, clause 7.7 allows you to use an > alertnate test set-up. > We do not use a decoupler to test our high speed network. We test the > network before and after the surge application and disconnect > the auxilary > equipment with a relay for a short interval overlaping the surge > application. We have recommended to the manufacturer of the > surge generator > that the IEC/CENELEC techincal committee include this test method in a > revision of the standard. > > Richard Woods > Sensormatic Electronics > Tyco International > > > -----Original Message----- > From: [email protected] [mailto:[email protected]] > Sent: Wednesday, March 27, 2002 9:34 AM > To: [email protected] > Cc: [email protected] > Subject: RE: EMC test set-up for device with ethernet connection > > > > Here is one approach: > > Terminations: > You need actual or simulated traffic (data packets) on the > LAN. Terminate > cables per IEEE802.x; the LAN link is a transmission line and must be > correctly terminated (by LAN card or hub). Details depend on EUT > functionality. Wiring configuration for emissions and > immunity should be > similar. If the EUT connects to a PC only via LAN, then the > PC is AE; test > the EUT as a stand-alone. If there are cables (USB, RS-232) > to the PC or > other AE, you must decide based on typical equipment proximity. > > Functionality during emissions test: > I prefer constant signals for reproducibility. If EUT can > simulate traffic > internally, terminate the Ethernet cable to a PC LAN card and > shut off the > PC. If EUT is not an Ethernet node, set the PC's LAN card in > a loopback > mode (internal test routine) to send Ethernet data through > the EUT. Scan > all states supported by the EUT (10Mb, 100 Mb, full duplex, > half duplex). > > Functionality during immunity test: > Actual data traffic is needed because acceptance criteria > references data > quality. > Metrics: For unambiguous results, run a program that > transfers packets (or > files) and tabulates errors. Monitoring the collision rate > tells you if > communication is degrading (some hubs have collision rate LED's; > sophisticated monitoring equipment is also available). > Packet-transfer rate > degradation is a secondary effect. Ethernet CRC routines > resend corrupted > packets, higher Ethernet levels also provide correction. > Because of packet > resending, bit-error rate depends on where it is monitored. > > Tip: > Specialized Ethernet diagnostic equipment may survive immunity tests. > Isolate expensive monitoring equipment with low-cost hubs. > > David > > -----Original Message----- > From: [email protected] [mailto:[email protected]] > Sent: Wednesday, March 2 From - Sun Mar 31 05:04:14 2002 Return-Path: <[email protected]> Received: from ruebert.ieee.org ([140.98.193.10]) by mtiwgwc27.worldnet.att.net (InterMail vM.4.01.03.27 201-229-121-127-20010626) with ESMTP id <20020329162803.vdor12459.mtiwgwc27.worldnet.att....@ruebert.ieee.org>; Fri, 29 Mar 2002 16:28:03 +0000 Received: () by ruebert.ieee.org (Switch-2.1.0/Switch-2.1.0) id g2TGMOM14735 for emc-pstc-resent; Fri, 29 Mar 2002 11:22:24 -0500 (EST) Message-ID: <846BF526A205F84BA2B6045BBF7E9A6A01F13FC4@flbocexu05> From: [email protected] To: [email protected] Subject: RE: EMC test set-up for device with ethernet connection List-Post: [email protected] Date: Fri, 29 Mar 2002 11:21:37 -0500 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2653.19) Content-Type: text/plain; charset="iso-8859-1" Sender: [email protected] Precedence: bulk Reply-To: [email protected] X-Resent-To: Multiple Recipients <[email protected]> X-Listname: emc-pstc X-Info: Help requests to [email protected] X-Info: [Un]Subscribe requests to [email protected] X-Moderator-Address: [email protected] X-Mozilla-Status: 8011 X-Mozilla-Status2: 00000000 X-UIDL: <846BF526A205F84BA2B6045BBF7E9A6A01F13FC4@flbocexu05> What is the highest data rate that you have been able to achieve through the decoupler? Richard Woods Sensormatic Electronics Tyco International -----Original Message----- From: [email protected] [mailto:[email protected]] Sent: Friday, March 29, 2002 8:54 AM To: [email protected]; [email protected] Cc: [email protected] Subject: RE: EMC test set-up for device with ethernet connection Ari, Circuit diagram is EN61000-4-5: Figure 10. My coil was 20mH coil: www.wilcocorp.com P/N HFT-203 which has a DC resistance, R(L), of 2 ohms. The key is minimizing R(L). Ethernet incorporates internal threshold-detection and noise-rejection; low level signals are rejected both devices on the link. Twisted-Pair Ethernet is transformer-isolated at each end to eliminate DC; signal is inherently limited due to 100-ohm source impedence. David -----Original Message----- From: [email protected] [mailto:[email protected]] Sent: Thursday, March 28, 2002 2:26 AM To: [email protected] Cc: [email protected] Subject: RE: EMC test set-up for device with ethernet connection David, if you have a decoupling circuit that keeps the surge away but passes ethernet, how about posting the details here? Lots of us would be most interested! Ari > -----Original Message----- > From: ext [email protected] [mailto:[email protected]] > Sent: 27 March, 2002 22:20 > To: [email protected] > Cc: [email protected] > Subject: RE: EMC test set-up for device with ethernet connection > > > > Richard, > > We made our own decoupler with low-resistance 20mH coils. > You really should > have an active link during conditioning. Off-line surge will > not detect a > partitioned port; if there is no link, there can be no > partition. A slow > link is better than no link. > > David > > -----Original Message----- > From: [email protected] [mailto:[email protected]] > Sent: Wednesday, March 27, 2002 12:55 PM > To: [email protected] > Subject: RE: EMC test set-up for device with ethernet connection > > > > You will not be able to transfer data when the decoupling > network is added > for the I/O surge test per EN61000-4-5. The data rate through > the decoupler > is very low. However, clause 7.7 allows you to use an > alertnate test set-up. > We do not use a decoupler to test our high speed network. We test the > network before and after the surge application and disconnect > the auxilary > equipment with a relay for a short interval overlaping the surge > application. We have recommended to the manufacturer of the > surge generator > that the IEC/CENELEC techincal committee include this test method in a > revision of the standard. > > Richard Woods > Sensormatic Electronics > Tyco International > > > -----Original Message----- > From: [email protected] [mailto:[email protected]] > Sent: Wednesday, March 27, 2002 9:34 AM > To: [email protected] > Cc: [email protected] > Subject: RE: EMC test set-up for device with ethernet connection > > > > Here is one approach: > > Terminations: > You need actual or simulated traffic (data packets) on the > LAN. Terminate > cables per IEEE802.x; the LAN link is a transmission line and must be > correctly terminated (by LAN card or hub). Details depend on EUT > functionality. Wiring configuration for emissions and > immunity should be > similar. If the EUT connects to a PC only via LAN, then the > PC is AE; test > the EUT as a stand-alone. If there are cables (USB, RS-232) > to the PC or > other AE, you must decide based on typical equipment proximity. > > Functionality during emissions test: > I prefer constant signals for reproducibility. If EUT can > simulate traffic > internally, terminate the Ethernet cable to a PC LAN card and > shut off the > PC. If EUT is not an Ethernet node, set the PC's LAN card in > a loopback > mode (internal test routine) to send Ethernet data through > the EUT. Scan > all states supported by the EUT (10Mb, 100 Mb, full duplex, > half duplex). > > Functionality during immunity test: > Actual data traffic is needed because acceptance criteria > references data > quality. > Metrics: For unambiguous results, run a program that > transfers packets (or > files) and tabulates errors. Monitoring the collision rate > tells you if > communication is degrading (some hubs have collision rate LED's; > sophisticated monitoring equipment is also available). > Packet-transfer rate > degradation is a secondary effect. Ethernet CRC routines > resend corrupted > packets, higher Ethernet levels also provide correction. > Because of packet > resending, bit-error rate depends on where it is monitored. > > Tip: > Specialized Ethernet diagnostic equipment may survive immunity tests. > Isolate expensive monitoring equipment with low-cost hubs. > > David > > -----Original Message----- > From: [email protected] [mailto:[email protected]] > Sent: Wednesday, March 27, 2002 3:36 AM > To: [email protected] > Subject: EMC test set-up for device with ethernet connection > > > > Hello newsgroup readers, > Question about the EMC test set-up for Emission + Immunity. > We are developing a product which can be connected to the > ethernet / LAN/ > Internet. > Do we need to connect the product to a PC (with ethernet card) in the > anechoic room or can we decide to place the PC outside the > anechoic room. Or > can we test ONLY with an cable with NO termination. > > What is your opinion > Thanks in advance, > > Jan Mobers > > > ------------------------------------------- > 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: > [email protected] > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Ron Pickard: [email protected] > Dave Heald: [email protected] > > For policy questions, send mail to: > Richard Nute: [email protected] > Jim Bacher: [email protected] > > All emc-pstc postings are archived and searchable on the web at: > http://ieeepstc.mindcruiser.com/ > Click on "browse" and then "emc-pstc mailing list" > > ------------------------------------------- > 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: > [email protected] > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Ron Pickard: [email protected] > Dave Heald: [email protected] > > For policy questions, send mail to: > Richard Nute: [email protected] > Jim Bacher: [email protected] > > All emc-pstc postings are archived and searchable on the web at: > http://ieeepstc.mindcruiser.com/ > Click on "browse" and then "emc-pstc mailing list" > > ------------------------------------------- > 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: > [email protected] > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Ron Pickard: [email protected] > Dave Heald: [email protected] > > For policy questions, send mail to: > Richard Nute: [email protected] > Jim Bacher: [email protected] > > All emc-pstc postings are archived and searchable on the web at: > http://ieeepstc.mindcruiser.com/ > Click on "browse" and then "emc-pstc mailing list" > > ------------------------------------------- > 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: > [email protected] > with the single line: > unsubscribe emc-pstc > > For help, send mail to the list administrators: > Ron Pickard: [email protected] > Dave Heald: [email protected] > > For policy questions, send mail to: > Richard Nute: [email protected] > Jim Bacher: [email protected] > > All emc-pstc postings are archived and searchable on the web at: > http://ieeepstc.mindcruiser.com/ > Click on "browse" and then "emc-pstc mailing list" > ------------------------------------------- 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: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list" ------------------------------------------- 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: [email protected] with the single line: unsubscribe emc-pstc For help, send mail to the list administrators: Ron Pickard: [email protected] Dave Heald: [email protected] For policy questions, send mail to: Richard Nute: [email protected] Jim Bacher: [email protected] All emc-pstc postings are archived and searchable on the web at: http://ieeepstc.mindcruiser.com/ Click on "browse" and then "emc-pstc mailing list"
