Tim,
I’ll provide a personal opinion. It may not be to the letter of the standard and does not reflect what the customers that buy equipment from the company I work for expect. You may notice some cynicism as well. Customers and standards are not always reasonable or practical. I see this as an extension to the thread that circulated recently that discussed standardized PCs and laptops. You are selling a mouse that cannot be used standalone. You are not selling a laptop or a PC or any other peripherals when you sell that mouse. What you want to do is characterize the performance of that mouse and provide reasonable assurance to the end-user that it will not have emissions over a limit and that it provides immunity to external stimuli. If there was some way you could magically make the mouse work sitting on a table all by itself you could accurately characterize the mouse. Unfortunately this is not the case. You have to introduce a PC or a laptop. You cannot be reasonably expected to test with every model your mouse could possibly work with, and in this economy you probably are not going to test with more than one laptop. You are going to use one that you have cherry-picked--your golden setup. After all, if you were to do some AC line test (like a dropout) and the PC that your mouse was connected to glitched your power, it was not the fault of your mouse. Something is wrong with the PC power supply design. You would find a PC that did not have that problem would you not? Why add any additional peripherals to the fray that could compromise your mouse testing? Better to go with the bare minimum so you can concentrate on the mouse. If you wanted to be real thorough you could put together a spec and some specialized test equipment that would do anything that could possibly happen to your mouse in the real world (whatever that is). Maybe there is an IEC committee with nothing better to do than write a mouse standard? You could spend a year putting the spec and setup together and exhaustively test it. Of course your boss, who wanted to minimize testing in the first place, would not be too happy with this approach. So where is the middle road? That is primarily up to your customers. What level of testing will they be happy with? Do they even care? Some requirements go overboard (like BSMI). Others leave it up to the manufacturer. Absent any dictates for your specific product you have to use engineering judgment that will keep your customers happy, protect your company’s interests, and meet the legal requirements. Protecting your company’s interests means looking out for compliance, customer satisfaction, time to market, and their bank account. I would like to think that testing your mouse with the laptop would be enough. What are other peripherals going to contribute besides their own problems that do not have anything to do with your mouse? If you peripheral were a printer that had serial, parallel, USB, and Ethernet port, I would expect all those ports to be tested. Your mouse only has its USB cable. If you were testing the laptop then I would expect you to test the USB, Ethernet, and video ports. But you are only interested in testing your mouse, not some other company’s laptop. Similarly, removing tests that should not have anything to do with your mouse and would be totally dependent on the laptop seems reasonable to me as well. Good luck! Dan From: [email protected] [mailto:[email protected]] Sent: Thursday, May 07, 2009 1:08 PM To: [email protected] Subject: [PSES] ANSI C63.4/CISPR 22 Testing Configuration Hello Group, I have a couple of questions regarding the minimum PC configuration when testing a USB device such as a mouse and the minimum testing requirements. CISPR 22 contains the following: For a personal computer or a personal computer peripheral, the minimum configuration consists of the following device grouped and tested together: a) personal computer; b) keyboard; c) visual display unit; d) external peripheral for each of two different types of available I/O protocols, such as serial, parallel, etc.; e) if the EUT has a dedicated port for a special-purpose device such as a mouse or joystick, that device shall be part of the minimum configuration. If my EUT is a USB mouse, and I use a laptop as the host PC and the laptop doesn't have serial or parallel ports, how does one address the minimum configuration? There are total of 3 USB ports, 1 video port, and 1 Ethernet port available on the PC. Also, for the testing (CISPR 22 & CISPR 24), I would like to only do radiated emission, ESD, and radiated immunity since the EUT is USB powered and the cable is less than 3 meters in length for any I/O tests. Is this legally allowed? My associates want to reduce testing costs so they want to avoid AC powerline testing and I/O cable testing. In my engineering experience, I have seen USB devices get affected when EFT is applied on a host PC powerline. Would RRL (Korea) allow the same policies as above? I will need to get KCC approval as well. We all know that they can be strictly by the book with no tolerance for deviation from the standard. Any documented references for allowing or not allowing the above issues would be appreciated. Thanks, Tim Pierce TAP Engineering ________________________________ Big savings on Dell's most popular laptops. Now starting at $449! <http://pr.atwola.com/promoclk/10012657 x1222382499x1201454962/aol?redir=http:% F%2Fad.doubleclick.net%2Fclk%3B214663472%3B36502367%3Bg> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher <[email protected]> David Heald <[email protected]> - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. To post a message to the list, send your e-mail to <[email protected]> All emc-pstc postings are archived and searchable on the web at http://www.ieeecommunities.org/emc-pstc Graphics (in well-used formats), large files, etc. can be posted to that URL. Website: http://www.ieee-pses.org/ Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas <[email protected]> Mike Cantwell <[email protected]> For policy questions, send mail to: Jim Bacher <[email protected]> David Heald <[email protected]>
