Re: Re[2]: Peripherals
Hi Roger, I think when they say that they want worse case, they are referring to maximizing possible emissions from a test set up (using any compliant devices as peripherals). If they were to request that you use the most rf-emitting peripherals that you can find, you'd be testing with a bunch of non-compliant pieces, and nobody'd be able to pass. Paul K. Chang TUV Telecom 508 460-9072 x235 -Original Message- From: roger...@astec-asia.com To: dir...@patriots.east.sun.com ; gmcintu...@packetengines.com ; s_doug...@ecrm.com ; Gary McInturff Cc: emc-p...@majordomo.ieee.org List-Post: emc-pstc@listserv.ieee.org Date: Thursday, September 03, 1998 10:36 AM Subject: Re[2]: Peripherals > > I heard from the test lab that you can use a "good system" as your > peripherals to test your EUT rather than test it with a "worst system" > to obtain worst case for CE and FCC compliance, is that right? As I > know for CE and FCC, they only require a "typical system", so you can > choose your "favorite system". Any comments? > > Regards, > Roger Hsu > > >__ Reply Separator _ >Subject: RE: Peripherals >Author: Gary McInturff at Internet >Date:9/2/98 10:09 AM > > >Dan, > Thank you very much for providing the paragraphs. I happen to be >away from my office and can't get to these documents handily. I follow >your logic on the DoC equipment modifications thread but (theirs always >a but(t)). We are now discussing interpretation and intent. I think that >the FEDS are allowing for a change in the field during test time. The >assumption is that you make a change that will be manufacturable. In >fact I always re-test to insure this is true, particularly if it is a >mechanical rather than component value change. As a manufacturing of the >actual EUT I have control over the production of the test item. I don't >have that luxury with other vendors equipment. They could change it, but >let's face it they are more likely to tell you that the only people they >have a problem with is when your equipment, and do nothing. So in this >case documenting the change doesn't really solve the problem unless you >were to modify each peripheral as well. > I guess I should point out that I don't have a huge problem. On >occasion I have some troubles with somebody else's stuff and I have no >reason to believe it to be anything other than the single sample I >happen to be looking at. Its more that I don't have the time in the >schedule, or the nature to mess around during tests. I look for rock >solid peripherals and won't use one unless I first check it out and am >satisfied that it not only meets the limits but provides some margin to >those limits. > Thanks again Dan. > Gary > > > -Original Message- > From: dir...@patriots.east.sun.com >[SMTP:dir...@patriots.east.sun.com] > Sent: Tuesday, September 01, 1998 12:52 PM > To: gmcintu...@packetengines.com; s_doug...@ecrm.com > Cc: emc-p...@majordomo.ieee.org > Subject: Re: Peripherals > > All, > > I believe you guys are referring to 47CFR2.1033, > Application for certification: > > (8) If the equipment for which certification is being >sought > must be tested with peripheral or accessory devices >connected > or installed, a brief description of those peripherals >or > accessories. The peripheral or accessory devices shall >be > unmodified, commercially-available equipment. > > See also the previous section, 47CFR2.1031: > > The general provisions of this subpart [section] 2.901 >et seq. > shall apply to applications for and grants of >certification. > > As for products only subject to a Declaration of Conformity, > there is this requirement in 47CFR2.1075a (Retention of >records): > > (1) A record of the original design drawings and >specifications > and all changes that have been made that may affect > compliance with the requirements of [section] 2.1073. > > My interpretation is that unmodified, commercially-available > support equipment are only required for FCC Certification. > For Declarations of Conformity, I would take the >retention-of-records > requirements one step further. I would not modify support >equipment > unless it does not disguise emissions from the EUT, and I would > justify it in the test report per 47CFR2.1075a3 (Retention of >records): > > (iv) A description of the equipment under test (EUT) and > support equipment connected to, or installed within, the >EUT; > > To be fair, one argument against my intepretation is the >following > section, which explicitly requires tha
RE: Re[2]: Peripherals
Roger That is true, but if your company sells other components that could be used in the 'good system' then you must use your own products. The assumption is that your sales personnel will not sell a competitors printer (etc) in place of your own, therefore for the system test to be valid any of the required peripherals (or PC components) that your company makes must be used in the 'good system to support your EUT. John Mowbray > -Original Message- > From: roger...@astec-asia.com [SMTP:roger...@astec-asia.com] > Sent: Thursday, September 03, 1998 5:49 PM > To: dir...@patriots.east.sun.com; gmcintu...@packetengines.com; > s_doug...@ecrm.com; Gary McInturff > Cc: emc-p...@majordomo.ieee.org > Subject: Re[2]: Peripherals > > > I heard from the test lab that you can use a "good system" as your > peripherals to test your EUT rather than test it with a "worst > system" > to obtain worst case for CE and FCC compliance, is that right? As I > know for CE and FCC, they only require a "typical system", so you can > > choose your "favorite system". Any comments? > > Regards, > Roger Hsu > > > __ Reply Separator > _ > Subject: RE: Peripherals > Author: Gary McInturff at Internet > Date:9/2/98 10:09 AM > > > Dan, > Thank you very much for providing the paragraphs. I happen to be > away from my office and can't get to these documents handily. I follow > your logic on the DoC equipment modifications thread but (theirs always > a but(t)). We are now discussing interpretation and intent. I think that > the FEDS are allowing for a change in the field during test time. The > assumption is that you make a change that will be manufacturable. In > fact I always re-test to insure this is true, particularly if it is a > mechanical rather than component value change. As a manufacturing of the > actual EUT I have control over the production of the test item. I don't > have that luxury with other vendors equipment. They could change it, but > let's face it they are more likely to tell you that the only people they > have a problem with is when your equipment, and do nothing. So in this > case documenting the change doesn't really solve the problem unless you > were to modify each peripheral as well. > I guess I should point out that I don't have a huge problem. On > occasion I have some troubles with somebody else's stuff and I have no > reason to believe it to be anything other than the single sample I > happen to be looking at. Its more that I don't have the time in the > schedule, or the nature to mess around during tests. I look for rock > solid peripherals and won't use one unless I first check it out and am > satisfied that it not only meets the limits but provides some margin to > those limits. > Thanks again Dan. > Gary > > > -Original Message- > From: dir...@patriots.east.sun.com > [SMTP:dir...@patriots.east.sun.com] > Sent: Tuesday, September 01, 1998 12:52 PM > To: gmcintu...@packetengines.com; s_doug...@ecrm.com > Cc: emc-p...@majordomo.ieee.org > Subject: Re: Peripherals > > All, > > I believe you guys are referring to 47CFR2.1033, > Application for certification: > > (8) If the equipment for which certification is being > sought > must be tested with peripheral or accessory devices > connected > or installed, a brief description of those peripherals > or > accessories. The peripheral or accessory devices shall > be > unmodified, commercially-available equipment. > > See also the previous section, 47CFR2.1031: > > The general provisions of this subpart [section] 2.901 > et seq. > shall apply to applications for and grants of > certification. > > As for products only subject to a Declaration of Conformity, > there is this requirement in 47CFR2.1075a (Retention of > records): > > (1) A record of the original design drawings and > specifications > and all changes that have been made that may affect > compliance with the requirements of [section] 2.1073. > > My interpretation is that unmodified, commercially-available > support equipment are only required for FCC Certification. > For Declarations of Conformity, I would take the > retention-of-records > requirements one step further. I would not modify support > equipment > unless it does not disguise emissions from the EUT, and I would > justify it in the test report per 47CFR2.1075a3 (Retention of > recor
Re[2]: Peripherals
I heard from the test lab that you can use a "good system" as your peripherals to test your EUT rather than test it with a "worst system" to obtain worst case for CE and FCC compliance, is that right? As I know for CE and FCC, they only require a "typical system", so you can choose your "favorite system". Any comments? Regards, Roger Hsu __ Reply Separator _ Subject: RE: Peripherals Author: Gary McInturff at Internet List-Post: emc-pstc@listserv.ieee.org Date:9/2/98 10:09 AM Dan, Thank you very much for providing the paragraphs. I happen to be away from my office and can't get to these documents handily. I follow your logic on the DoC equipment modifications thread but (theirs always a but(t)). We are now discussing interpretation and intent. I think that the FEDS are allowing for a change in the field during test time. The assumption is that you make a change that will be manufacturable. In fact I always re-test to insure this is true, particularly if it is a mechanical rather than component value change. As a manufacturing of the actual EUT I have control over the production of the test item. I don't have that luxury with other vendors equipment. They could change it, but let's face it they are more likely to tell you that the only people they have a problem with is when your equipment, and do nothing. So in this case documenting the change doesn't really solve the problem unless you were to modify each peripheral as well. I guess I should point out that I don't have a huge problem. On occasion I have some troubles with somebody else's stuff and I have no reason to believe it to be anything other than the single sample I happen to be looking at. Its more that I don't have the time in the schedule, or the nature to mess around during tests. I look for rock solid peripherals and won't use one unless I first check it out and am satisfied that it not only meets the limits but provides some margin to those limits. Thanks again Dan. Gary -Original Message- From: dir...@patriots.east.sun.com [SMTP:dir...@patriots.east.sun.com] Sent: Tuesday, September 01, 1998 12:52 PM To: gmcintu...@packetengines.com; s_doug...@ecrm.com Cc: emc-p...@majordomo.ieee.org Subject: Re: Peripherals All, I believe you guys are referring to 47CFR2.1033, Application for certification: (8) If the equipment for which certification is being sought must be tested with peripheral or accessory devices connected or installed, a brief description of those peripherals or accessories. The peripheral or accessory devices shall be unmodified, commercially-available equipment. See also the previous section, 47CFR2.1031: The general provisions of this subpart [section] 2.901 et seq. shall apply to applications for and grants of certification. As for products only subject to a Declaration of Conformity, there is this requirement in 47CFR2.1075a (Retention of records): (1) A record of the original design drawings and specifications and all changes that have been made that may affect compliance with the requirements of [section] 2.1073. My interpretation is that unmodified, commercially-available support equipment are only required for FCC Certification. For Declarations of Conformity, I would take the retention-of-records requirements one step further. I would not modify support equipment unless it does not disguise emissions from the EUT, and I would justify it in the test report per 47CFR2.1075a3 (Retention of records): (iv) A description of the equipment under test (EUT) and support equipment connected to, or installed within, the EUT; To be fair, one argument against my intepretation is the following section, which explicitly requires that modifications to the EUT (but not support equipment,) be documented: (viii) A description of any modifications made to the EUT by the testing company or individual to achieve compliance with the regulations; Please also note that the requirements of 47CFR2.1075a (Retention of records) may not apply to equipment assembled using modular components. See 47CFR2.1075b. My 2 cents, Dan > From owner-emc-p...@majordomo.ieee.org Tue Sep 1 11:28:03 1998 > Date: Tue, 01 Sep 1998 08:36:09 -0400 > Subject: Re: Peripherals > To: gmcintu...@packetengines.com > Cc: emc-p...@majordomo.ieee.org > From: s_doug...@ecrm.com (Scott Douglas) > MIME-Version: 1.0 > Content-Transfer-Encoding: 8bit > X-Resent-To: Multiple Recipients > X-Listname: emc-pstc > X-Info: Help requests to emc-pstc-requ...@majordomo.ieee.org > X-Info: [Un]Subscribe requests to majord...@majordomo.ieee.org > X-Moderator-Address: emc-pstc-appro...@majordomo.ieee.org > > Gary, > > I have had my problems with support equipment and peri
Re[2]: Peripherals
FCC Rules do address this issue: FCC Rules Part 15, Section 15.31 (k) discusses "composite systems" which incorporate different devices contained in either a single enclosure or in separate enclosure connected by wire or cable. Among other things, this paragraph states "In no event may the measured emissions of the composite system exceed the highest level permitted for an individual component". Hence, a device cannot be certified or verified as class B if tested in a class A composite system, because the composite system will exceed the class B limits. It would also follow that a device cannot be verified as class A unless the composite system in which it is tested meets the class A limits. Jim Hulbert Pitney Bowes __ Reply Separator _ Subject: Re: Peripherals Author: at SMTPGWY List-Post: emc-pstc@listserv.ieee.org Date:9/1/98 8:36 AM Gary, I have had my problems with support equipment and peripherals also. And, having used a lot of big name products, mostly computers, etc., I was surprised at how many of them failed when my product was turned off and theirs was left running. It is quite common for test house guys to say " Oh, that's the host, we'll ignore that one". I finally got to the point where I put them outside the test environment, i.e. below the floor or outside the shield room. I do this because I don't sell them and figure that if I run self test mode and don't see the problem, then it is either the other guy's stuff or my I/O. If it is my I/O, I will fix it. If it is the other guy's stuff, I leave it alone. I can't / won't fix their non-compliant equipment, don't have either the time or money to do so. I did eventually find a quiet PC and monitor which I guard with my life. I have even coerced the software guys into making their latest stuff play with my older PC so I can keep using it. I can't point to the reference you are asking for. It seems to me that if the support / host equipment is required to be on the table during test, then the entire thing must comply. It can be difficult to point the finger at one piece and say that it is the source of the problem, especially on the immunity side. If you try several different pieces of support equipment and the "system" continues to fail, it probably is within the common unit, i.e. your product. If you find that changing the support equipment can make the "system" pass, then either you have a marginal product or a too-sensitive support equipment. In this case, you have a decision to make, and a tough one at that. Sorry I am not more help on this one. Regards, Scott s_doug...@ecrm.com - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.com with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, ri...@sdd.hp.com, or roger.volgst...@compaq.co (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.com with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, ri...@sdd.hp.com, or roger.volgst...@compaq.co (the list administrators).
Re[2]: Peripherals
In order to meet the requirements of the EMC Directive, it has always been my understanding that the complete system must be tested. This refers to any peripherals that are necessary to operate the EUT and any other peripherals that the manufacturer states are part of the system. The EMC Directive Guidelines is very clear on what is considered a "system". Unfortunately, we use a PC from a large well known manufacturer (I will resist the temptation to name them) that has failed Class B radiated emissions by more than 10dB on various models with various monitors. It appears that some manufacturers use their "perfect test computers", or ignore the effects of the computer when evaluating their EUT's. I do not believe that this is acceptable. I would love to receive some official documentation that states that this practice is acceptable. Life would be good. Regards Joe Martin EMC/Product Safety Engineer P.E. Applied Biosystems marti...@perkin-elmer.com __ Reply Separator _ Subject: RE: Peripherals Author: rehel...@mmm.com at INTERNET List-Post: emc-pstc@listserv.ieee.org Date:9/2/98 11:58 AM The last time I asked the FCC for a ruling, I was told that peripherals used for a "typical system" that were not sold with the EUT but required for the EUT to function could not be modified, covered up, shielded, moved out of the test area, etc. and had to be tested with the EUT. The equipment I had at the time fell under FCC Part 15. What is the ruling/opinions on this subject for Europe? - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.com with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, ri...@sdd.hp.com, or roger.volgst...@compaq.co (the list administrators). - This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to majord...@ieee.com with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to ed.pr...@cubic.com, ri...@sdd.hp.com, or roger.volgst...@compaq.co (the list administrators).
