Am 07.09.2012 um 16:37 schrieb Belli Button: > Just about any cheap Digital scope will do this these days, set the display > to 'persist' and then measure the width of the line that forms.
for a one-shot measurement, that's fine; that doesnt extend to, say, measuring jitter or trapping trap outlyers with new kernels, platforms and interface hardware I think the relevant measurement scenario at hand is more like the hardware side of what is laid of it this talk: http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&ved=0CCMQFjAA&url=http%3A%2F%2Felinux.org%2Fimages%2F8%2F8e%2FReal-time_Measurement-ELC2010-final.pdf&ei=aRtKULTdA9PT4QTXyIHIBg&usg=AFQjCNHpTQ1iYevViznCNfXuaTXs2OGtEg&sig2=DL62aWSUFjlFmrJ951B1oA - Michael > > Greg > > > ----- Original Message ----- > From: "Michael Haberler" <mai...@mah.priv.at> > To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net> > Sent: Friday, September 07, 2012 4:17 PM > Subject: Re: [Emc-users] [OT] measuring real-world latency,was Re: worsk: > sim parport component > > >> >> Am 07.09.2012 um 16:04 schrieb Kent A. Reed: >> >>> On 9/3/2012 4:51 PM, Michael Haberler wrote: >>>> well, that seems to work just fine - no major surprises >>>> >>>> here's as screenshot from a logic analyzer connected to an Intel D5252 >>>> parport, running the userland parport driver in sim mode >>>> >>>> http://static.mah.priv.at/public/uparport.png >>>> >>>> it's a 1kHz square; there are delays of up to 4ms in this trace. >>> >>> Logic analyzers, oscilloscopes---I know the drill but I no longer have >>> easy access to such instrumentation. >>> >>> Has anyone come up with simple (e.g., inexpensive) ways to measure >>> latencies in the range we are interested in - say a range of 1K - 100K >>> pulses per second with pulse widths on the order of microseconds. >> >> I bit the bullet a while ago and got me an Intronix LogicPort at a setback >> of $385.- (http://www.pctestinstruments.com/); but very robust, >> unfortunately locked in to Windows platform and hence unsuited for >> scripted interaction for automated tests; I've suggested a scripting api >> or at least documenting their USB interface to enable that but it seems >> they dont care - looks like their usage model idea revolves around >> "engineer in lab, with lab coat, in front of Windows PC" >> >> http://www.sump.org/projects/analyzer/ might be a cheaper option >> >> this german website has a few other project mentioned: >> http://www.mikrocontroller.net/articles/Logic_Analyzer#SUMP_Logic_Analyzer >> and down from there >> >> -m >> >>> >>> Back when the world was young and we wannabe researchers avidly read >>> from cover to cover in each new data-book from the likes of TI and >>> Motorola, I used to design and build comparable circuits, but then I had >>> the bench instrumentation to test my testers, so to speak. Now I'm in a >>> catch-22 situation. >>> >>> If I could turn back the clock, I'd probably use this problem as a >>> reason to explore FPGA, but instead I'm noodling about using a >>> Beaglebone or somesuch as a starter. >>> >>> Thoughts, anyone? >>> >>> Regards, >>> Kent >>> >>> >>> ------------------------------------------------------------------------------ >>> Live Security Virtual Conference >>> Exclusive live event will cover all the ways today's security and >>> threat landscape has changed and how IT managers can respond. Discussions >>> will include endpoint security, mobile security and the latest in malware >>> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ >>> _______________________________________________ >>> Emc-users mailing list >>> Emc-users@lists.sourceforge.net >>> https://lists.sourceforge.net/lists/listinfo/emc-users >> >> >> ------------------------------------------------------------------------------ >> Live Security Virtual Conference >> Exclusive live event will cover all the ways today's security and >> threat landscape has changed and how IT managers can respond. Discussions >> will include endpoint security, mobile security and the latest in malware >> threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ >> _______________________________________________ >> Emc-users mailing list >> Emc-users@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/emc-users > > > -------------------------------------------------------------------------------- > > > > No virus found in this incoming message. > Checked by AVG - www.avg.com > Version: 8.5.455 / Virus Database: 271.1.1/5247 - Release Date: 09/03/12 > 18:34:00 > > > ------------------------------------------------------------------------------ > Live Security Virtual Conference > Exclusive live event will cover all the ways today's security and > threat landscape has changed and how IT managers can respond. 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