On Monday 24 April 2017 13:11:08 Chris Albertson wrote: > On Mon, Apr 24, 2017 at 3:05 AM, Gene Heskett <[email protected]> wrote: > > On Monday 24 April 2017 01:17:33 dave wrote: > > > On 04/23/2017 08:30 PM, Gene Heskett wrote: > > > > On Sunday 23 April 2017 23:14:34 dave wrote: > > > >> On 04/23/2017 12:44 PM, Chris Albertson wrote: > > > >>> Looks like this is a dead end technology. Everyone has gone > > > >>> with HDMI. > > > >>> > > > >>> But really you don't need much to send a differential signal > > > >>> to a stepper driver Anything that can invert a 5V logic signal > > > >>> will work. The drivers don't want RS422 levels, just logic > > > >>> levels. and the receiver is built into the driver > > > >>> > > > >>> > > > >>> But today deferential pairs are outperforming older fiber > > > >>> technology by orders of magnitude. toslink is dead easy to > > > >>> use but its s at least 30 years old. The best serial cables > > > >>> on the consumer mass market are going a few ten's a giga bits > > > >>> per second. > > > >>> > > > >>> On Sun, Apr 23, 2017 at 10:18 AM, Gene Heskett > > > >>> <[email protected]> > > > > > > > > wrote: > > > >>>> On Sunday 23 April 2017 10:03:21 dave wrote: > > > >>>>> the foxcon stuff looks a bit pricey. However ... > > > >>>>> > > > >>>>> http://www.mouser.com/Toshiba/Optoelectronics/Fiber-Optics/F > > > >>>>>iber -O ptic > > > >>>>> -Transmitters-Receivers-Transceivers/TOSLINK/_/N-6qrgo?P=1z0 > > > >>>>>zkx4 Z1 ybqc2 q > > > >>>>> > > > >>>>> It actually looks affordable including cables. 10 Mb/s but > > > >>>>> that should handle anything linuxcnc needs. 10' simplex > > > >>>>> cables for a couple of $. > > > >>>>> > > > >>>>> https://www.monoprice.com/Product?p_id=2669&gclid=Cj0KEQjwof > > > >>>>>HHBR DS 0Pnh > > > >>>>> pef89ucBEiQASEp6LIW3Tu9rI-YsCuV7XvPZJEDJ4M80OU09A9vYGSpppjMa > > > >>>>>Ajjx 8P 8HAQ > > > >>>>> > > > >>>>> Dave > > > >>>> > > > >>>> Only 2 transmitter modules stocked at well over a 10 dollar > > > >>>> bill each. No receiver modules are stocked at any price. All > > > >>>> hat, no cattle. > > > >>>> > > > >>>> That is a good enough price on ready-made cables if I wanted > > > >>>> to do it with to$link. But the above hardware pricing is > > > >>>> not a viable choice when you need lots of them. I have no > > > >>>> intention of spending north of $600 for 10 fiber links. > > > >>>> > > > >>>> Good info Dave, thanks. > > > >> > > > >> So what you really need ??? is inexpensive Rx and Tx and then > > > >> plastic fiber plus an epoxy to bond the > > > >> two with low losses into a usable static configuration. Eh? > > > >> > > > >> Dave > > > > > > > > You are getting warmer, Dave, although I'd druther use go2 or > > > > goop as there's a small chance of getting it apart again should > > > > it be needed. > > > > > > > > Cheers, Gene Heskett > > > > > > AFIK you want a clear adhesive with a refractive index close to > > > 1.49 to match the PMMA core of the fiber. > > > > > > Dave > > > > The adhesive, as long as it doesn't touch the core, only the jacket, > > shouldn't be optically important. > > No, the "goop" absolutely HAS to touch the core file. An "air gap" > absolutely will not work. The invention of this special refractive > index gell is what made it possible for normal humans to field > terminate fiber. Now days the modern connector only has to hold the > fiber is alignment then this gell is squeezed in under pressure and > fils the air gap. > > In the old days they used to need to optically polish the fiber ends > but now the "goop" is automatically pushed into the fractured end of > the fiber by the connector. Here is a video (link below) that shows > how a modern connector is used. > > He does say in the video that the "old kind" is still used but today > only in a factory environment. > > These connectors are not cheap and still require practice. You will > water a bunch of them learning how to use them) Better to buy "patch > cords" that are pre terminated. OK to TOSLINK is no longer the way to > go. Fiber Ethernet is common, try that. > > This video is good https://youtu.be/SthwoIDprrk > Informative.
But having spent a couple hours on the phone, and 2 more in chats with tech support, without finding anyone interested in selling less than 10k qty's, I guess I am about burned out on the idea. Since I've managed to come up with a snubber circuit to put between an input to the 7i90, and have enough 1N914's either on hand or in the USPO system, and some circuit boards to make them on, I guess that is the path I'll take. 5 ea 1n914's from ground to the signal line, anode up, makes a good clipper, and a single one paralleling the 5, but cathode up seems to prevent below ground undershoots from hurting the 7i90's inputs, and a .005 ceramic across the lot which gobbles up at least 90% of the noise, is working well over 15' of cat-6 jumper cable and no shielding to speak of. pwr & ground on one pair, a pair each carrying the quadrature from the dials, and another pair, the last pair in the cable carries the pushbuttons back. I'll change the wiring from the drivers into a piece of star-quad or a look-a-like thats not as flexible, whose shielding should gobble up some of the noise, and feed the + side of the drivers opto's from the + line powering the 7i90. Might use 6 diodes, anode up as that should still clip it before the voltage gets high enough to blow an opendrain gpio. No parcels today, plus its wet and in the 50's in F temps today so I camped in & took better care of my lady. Maybe I can make some progress at getting the timedelay out of the hal file and a oneshot doing that job. I can see where I've made some mistakes, and un-needed complexity that I can simplicate out of it by a re-write because now I have a better idea of what needs to be done. So thats the news from Weston WV for tonight. 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) Genes Web page <http://geneslinuxbox.net:6309/gene> ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
