On Monday 14 December 2015 19:11:49 Jerry Scharf wrote: > Hi, > > Just did a super quick google search and came up with a fairchild > optocoupler hcpl2530 that will do 1Mbps. ~1.80 USD quantity 1. > Isolation to 480v and good common mode rejection. There are a number > of devices in similar and better speeds. > > That's not anywhere near the top speed for laser/detector systems, > which now run to 100Gbps and beyond. > > opto stuff is so much cheaper than it used to be. The combination of > insane laser volume and the demand for ultra speed detectors have made > fast stuff really cheap. > > jerry > I was wondering if faster stuff was filtering down into the afordable category in the last decade, But only 480 volt isolation? that would have to be mesa isolated on the same substrate, edge emitting diodes facing edge sensitive transistors. I think it depends on the environment if thats enough isolation. With noise from higher speed/volatge stepper drivers nearby, I'd be a tad nervous.
> On Mon, Dec 14, 2015 at 1:57 PM, Gene Heskett <ghesk...@wdtv.com> wrote: > > On Monday 14 December 2015 16:01:26 Ben Potter wrote: > > > > Note that those setup and hold times are relative to the riseing > > > > edge of > > > > > > the (step?) pulse, and the next line is not so specific, but I > > > expect it needs to be checked by a dual trace scope for both > > > > > > > conditions > > > > > > I'm very tempted to pull the G540 from the router and rig up a > > > test bench test to see if I can get my head around why this is > > > happening. Might get time over christmas. > > > > > > Would be nice to know why inverting the step output works for me, > > > rather than 'it just does' I'm starting to suspect that the 5i25 > > > obeys the set timings, whereas mach on a parallel port uses them > > > as a minimum guide, and frequently exceeds them. > > > > > > > > I have no additional opto-isolation in that path - I believe > > > > > that the G540 uses fast opto's on all the parallel port pins > > > > > (from the manual, I'm sure there was a post on cnczone > > > > > detailed the choice of isolater somewhere) > > > > > > > > Thanks for that , so it would have been DIRSETUP/DIRHOLD that I > > > > was > > > > > > concerned with. > > > > > > I managed to dig out the thread where Mariss of Gecko was talking > > > about opto circuits. > > > http://www.cnczone.com/forums/general-cnc-machine-related-electron > > >ics/ 23216- optoisolator-circuit.html > > > > > > Posts #2 and #6 are particularly interesting (not sure on > > > cross-post etiquette here), and possibly give a hint as to the > > > root cause of my problem. > > > > > > > > <snip> [...] Cheers, Gene Heskett -- "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) Some mill pix are at: Genes Web page <http://geneslinuxbox.net:6309/gene/GO704-pix> ------------------------------------------------------------------------------ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
