On Monday 22 June 2015 10:05:49 Dave Caroline wrote: > I too have seen bad break out boards but recently got one of > http://www.ebay.co.uk/itm/171802685847 > > There seems to be a couple of versions of it on fleabay only tried the > one > > this has direct 74hct driving the opto in the driver rather than have > its own output optos, sensible in my opinion, which also means it can > drive high or low side optos
True, and as the inputs on the latest crop of decent drivers like a DM542, are totally floating, any additional opto delays are NOT icing on the cake. They are a limiting PITA. Knowing the load on the breakout board is another isolated opto, means we could put OC bugs on the breakout board that could handle even 250ma relays if a free-wheeling diode were also there. It doesn't say, but I am assuming the USB port on one of these is just for power? I see, when I did a search, prices as low as 7 pounds, which isn't too bad except for the shipping lags from the UK. Searching the .com version, I see several for about that in dollars, and 3 or 4 of them look as if the only opto's are in the inputs, the outputs are just buffered I believe. These are parport driven, and stealing 5 volts from a usb cable. One less *&^$ wall wart to screw with. And I just went out and rigged the monster Z motor, its 60 volt psu, and the function generator for a spin test. I am impressed. Still set at 51200 steps per rev (read that carefully, the specs have changed) which actually means step/256, and that motor has now been running with an input step rate of 1.4Mhz for 20 minutes or so. No great amount of heat, and the psu fan hasn't even started. I am guessing the shaft revs are around 2000 rpms. But the calculator says 1640, still not a disappointment for a 1200 or 1600 oz motor. I need to look it up on Longs site. Slow it down to a crawl of about 1 rpm and its dead silent until it hits one of several resonance points and starts crawling across the board its on at about 30 revs. First one is the noisiest, and there are 3 or 4 more, but 10% off that magic speed and its very hard to hear. A nema 34, running at what the controller switches say is its nameplate RMS amps, 3.5. If this thing can't turn the screw, someone snuck in and welded it. So yes, the opto's in the DM series drivers would appear to be a considerable improvement over those in my now 4 yo 2M542's, which I thought at the time were the cats meow. This is about 4 to 5x faster. Now, if that 5i25 would just materialize. :) > Dave Caroline > > On 22/06/2015, Gene Heskett <[email protected]> wrote: > > On Monday 22 June 2015 03:57:06 Steve Stallings wrote: > >> Proceed with caution. This board uses slow opto-couplers > >> in the data port output signals that are typically set > >> up as step and direction outputs. Many users have reported > >> problems due to the inability to pass fast signals. > >> > >> Additionally some variations of this board connect the > >> ground on the output sides of the opto couplers to the > >> same signal as the ground on the input sides and thus > >> do not actually isolate the ground path. > > > > That much is documented. As for the slow opto's, that doesn't > > surprise me. While it looks well made, its lack of docs, real docs > > that spec those speeds etc, makes me think its a $3.75 card in > > Kowloon. > > > > Yesterday I ran stepconf on the normal parport, with my pocket scope > > watching the outputs, and I get good solid direction reversals on > > the "dir" pins, but zip on the step pins. I suspect that without an > > adjustable reset time, its not going to work even if this box has > > horrible latency, restricting it to a 45u-s base thread or slower. > > > > The docs tend to say both are open collector (OC) and show a pullup. > > This is with a 5v 1 amp supply connected to the 5 & gnd pins, and > > the jumpers on, which commons both grounds and 5 volt lines. I don't > > think the step pulses are wide enough to get thru those opto's, but > > will get out the big scope and check today. > > > > I am in love with the C1G from cnc4pc as it has all these nice > > pretty leds to tell you whats going on, and the opto's are faster > > than stink too, so I guess I'll get me a 3rd one for this machine. > > > > I also see the latest versions of the *542 and *860 drivers can now > > do 51200 microsteps, which if combined with the correct currents > > should be able to move steppers as close to silently as they can be > > moved. > > > > Unforch, while I can probably get steps out of a 5i25 fast enough to > > get decent speeds, the interfaces between them, and likely the > > opto's in the DM542 and DM860 drivers, are not fast enough to take > > full advantage of that. > > > > That is likely one of the things I will do today since I am still > > waiting on the 5i25. Set up one motor, a 470oz, on the 36v supply > > that came with the kit, and see if the DM542 is faster than the > > 2M542. I doubt it unless the opto's are lasers. At 200 per rev, > > *51200=10,240,000 steps per revolution. As that would be a 1000% > > step forward in the "state of the art", I don't think so. > > > > In my tests with a 2M542 a couple of months back, using a duty cycle > > tweakable function generator, I was able to spin a 425oz motor close > > to 3000 revs in the /8 microstep mode, but ran out of opto speeds in > > the 2M542 at about 2200 revs (not quite 340 kilohertz at the > > function generator output when trying the /16 step setting. Most > > any divisor fell over at 330 to 340 kilohertz with the motor > > stalling silently. > > > > They seem to need a 2 u-sec step, and a 3 to 4 u-sec resting period > > at best. In this case, they were on & never turned off as the OC > > voiltage stayed within a few millivolts of ground. > > > > Slow opto's on this thing would explain my lack of results. > > > > One question though Steve, I had to put a power supply on it, I > > thought the parport had a 5 volt pin but don't have a pinout handy > > ATM. Do I have a bad parport? Or is my memory getting foggy? > > > >> Steve Stallings > >> > >> > -----Original Message----- > >> > From: Gene Heskett [mailto:[email protected]] > >> > Sent: Sunday, June 21, 2015 4:56 PM > >> > To: [email protected] > >> > Subject: [Emc-developers] Next prob, zero docs on the BOB > >> > supplied > >> > > >> > Which is a db25-1205. Google found it ok, but its a 17 megabyte > >> > .exe. > >> > > >> > Whats the usual linux program to open this winders stuff? > >> > > >> > 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> > >> > > >> > -------------------------------------------------------------- > >> > ---------------- > >> > _______________________________________________ > >> > Emc-developers mailing list > >> > [email protected] > >> > https://lists.sourceforge.net/lists/listinfo/emc-developers > >> > >> ------------------------------------------------------------------- > >>--- -------- Monitor 25 network devices or servers for free with > >> OpManager! OpManager is web-based network management software that > >> monitors network devices and physical & virtual servers, alerts via > >> email & sms for fault. Monitor 25 devices for free with no > >> restriction. Download now > >> http://ad.doubleclick.net/ddm/clk/292181274;119417398;o > >> _______________________________________________ > >> Emc-developers mailing list > >> [email protected] > >> https://lists.sourceforge.net/lists/listinfo/emc-developers > > > > 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> > > > > -------------------------------------------------------------------- > >---------- Monitor 25 network devices or servers for free with > > OpManager! OpManager is web-based network management software that > > monitors network devices and physical & virtual servers, alerts via > > email & sms for fault. Monitor 25 devices for free with no > > restriction. Download now > > http://ad.doubleclick.net/ddm/clk/292181274;119417398;o > > _______________________________________________ > > Emc-developers mailing list > > [email protected] > > https://lists.sourceforge.net/lists/listinfo/emc-developers > > ---------------------------------------------------------------------- >-------- Monitor 25 network devices or servers for free with OpManager! > OpManager is web-based network management software that monitors > network devices and physical & virtual servers, alerts via email & sms > for fault. Monitor 25 devices for free with no restriction. Download > now http://ad.doubleclick.net/ddm/clk/292181274;119417398;o > _______________________________________________ > Emc-developers mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-developers 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> ------------------------------------------------------------------------------ Monitor 25 network devices or servers for free with OpManager! OpManager is web-based network management software that monitors network devices and physical & virtual servers, alerts via email & sms for fault. Monitor 25 devices for free with no restriction. Download now http://ad.doubleclick.net/ddm/clk/292181274;119417398;o _______________________________________________ Emc-developers mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-developers
