What type of output driver is used on the 7i84? John > -----Original Message----- > From: Peter Wallace [mailto:p...@mesanet.com] > Sent: May 10, 2024 1:54 PM > To: Todd Zuercher > Cc: Todd Zuercher via Emc-users > Subject: Re: [Emc-users] Mesa Card Stepgens? > > On Fri, 10 May 2024, Todd Zuercher wrote: > > > Date: Fri, 10 May 2024 20:40:53 +0000 > > From: Todd Zuercher <to...@pgrahamdunn.com> > > To: Peter Wallace <p...@mesanet.com> > > Cc: Todd Zuercher via Emc-users <emc-users@lists.sourceforge.net> > > Subject: RE: [Emc-users] Mesa Card Stepgens? > > > > Peter, > > > > I've ran into another bit of a snag. I have a couple of 24v relays from > > Automationdirect. The resistance on the coils is about 635ohms. I thought > > that the outputs on the 7i84 were supposed to be ok with running a small > > relay with up to about 40mA without needing a flyback diode. It's close but > > just under that. Well, I've managed to kill 3 of the outputs with those > > relays (the outputs are stuck always on). I've put a couple of diodes on > > the relay coils, I hope that works and I don't ruin any more. What does it > > take to replace the chip or chips that would be damaged by this? > > 40 mA should be fine, it is possible this is the card that had power applied > backwards? > > We can replace the chips > > > > > Todd Zuercher > > P. Graham Dunn Inc. > > 630 Henry Street > > Dalton, Ohio 44618 > > Phone: (330)828-2105ext. 2031 > > > > -----Original Message----- > > From: Peter Wallace <p...@mesanet.com> > > Sent: Monday, April 15, 2024 5:09 PM > > To: Todd Zuercher <to...@pgrahamdunn.com> > > Cc: Todd Zuercher via Emc-users <emc-users@lists.sourceforge.net> > > Subject: RE: [Emc-users] Mesa Card Stepgens? > > > > [EXTERNAL EMAIL] Be sure links are safe. > > > > On Mon, 15 Apr 2024, Todd Zuercher wrote: > > > >> Date: Mon, 15 Apr 2024 20:22:03 +0000 > >> From: Todd Zuercher <to...@pgrahamdunn.com> > >> To: Peter Wallace <p...@mesanet.com>, > >> Todd Zuercher via Emc-users <emc-users@lists.sourceforge.net> > >> Subject: RE: [Emc-users] Mesa Card Stepgens? > >> > >> Thanks Peter, > >> > >> We've had this 7i85s for quite a while, and it must be one of the > >> early ones because I see DS34C87TM chips on it. > >> > >> I'm not sure I like the idea of using them single ended. But is a > >> +5v-0v single ended signal actually any better or even much different > >> than a +/-3v differential signal? How hard would it be to move the > >> last steepen over to the 7i88 and have all 8 of these stepgens on one > >> card? I am not planning on using the Smart Serial output on the 7i88. > >> The 3 servos have been working on the 7i85S for years and can stay there. > > > > Differential is needed and advised for servo drives with line receiver inputs, > however, with optocoupled input step/dir drives, there is little advantage to > differential mode. With optocoupled input step/dir drives the input will only > see ~3V drive in differential mode with the DS34C87 driver, so its better to > run in single ended mode with the 7I85S sinking so you get full 5V drive. > > > >> > >> I am using the Smart Serial connection on the 7i85s to connect a 7i84. > >> > >> If all else fails I can simply set all of the other steppers the same > >> as the slow one and leave it be. Even the slow one is working as fast > >> or faster than I was hoping it would, but a little more safety margin would > be nice. > > > > The drives are likely not rated for 3V input so you would probably be better > off if you ran single ended. > > > > > >> > >> Todd Zuercher > >> P. Graham Dunn Inc. > >> 630 Henry Street > >> Dalton, Ohio 44618 > >> Phone: (330)828-2105ext. 2031 > >> > >> -----Original Message----- > >> From: Peter Wallace <p...@mesanet.com> > >> Sent: Monday, April 15, 2024 3:41 PM > >> To: Todd Zuercher via Emc-users <emc-users@lists.sourceforge.net> > >> Cc: Todd Zuercher <to...@pgrahamdunn.com> > >> Subject: Re: [Emc-users] Mesa Card Stepgens? > >> > >> [EXTERNAL EMAIL] Be sure links are safe. > >> > >> On Mon, 15 Apr 2024, Todd Zuercher via Emc-users wrote: > >> > >>> Date: Mon, 15 Apr 2024 19:27:19 +0000 > >>> From: Todd Zuercher via Emc-users <emc-users@lists.sourceforge.net> > >>> To: "Enhanced Machine Controller (EMC)" > >>> <emc-users@lists.sourceforge.net> > >>> Cc: Todd Zuercher <to...@pgrahamdunn.com> > >>> Subject: [Emc-users] Mesa Card Stepgens? > >>> > >>> I was working on this machine where I need a whole bunch of extra > stepgens. I am using a Mesa 7i85S and a 7i88 connected to a 5i25 card. I was > testing some of the stepper drives and I noticed that with one of the > drive/motor combinations I am needing to use slightly longer step timing and > lower max velocity. I thought that this was odd, because all of the drives, > motors, and mechanicals are the same for all of the ones I was testing. The > only difference is that the slower one was connected to a stepgen on the > 7i85S and all of the others are on the 7i88. So just for curiosity sake I checked > the voltage at the input terminals of step/dir signals of the drive. On the > terminals connected to the 7i88 I found +/-5v, and on the one connected to > the 7i85S there is only +/-3v. This is the only difference I've been able to find > between the different joints in question. > >>> > >>> Does it make sense that the voltages would be different on the step/dir > outputs between the 7i85s and the 7i88? Does it make sense that the > difference would cause a difference in the required step timing? Why might > there be a difference between the output voltage on the two cards? > >>> > >>> Both cards are getting their 5v from the 5i25. The 7i85S is also connected > to 3 step/gen servo drives and their encoder's feedbacks. Is it possible that > the 5v drain from the encoders might be causing the lower voltage on the > 7i85S's outputs? > >> > >> > >> I would check the 5V rail at the 7I85S card, and if its low, power the > >> 7I85S directly from 5V rather the through the parallel cable. ALso the > >> very first lot (many years ago) of 7I85S cards were built with DS34C87 > >> drivers which do not have full 5V drive. If you have this card, you > >> can get 5V drive by using single ended sinking outputs and 5V+ to > >> drive step+ and 7i85s step- to drive > >> step- > >> > >>> > >>> Todd Zuercher > >>> P. Graham Dunn > >>> > Inc.<https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2 > >>> F > >>> > https://nam04.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww > . > >>> > pgrahamdunn.com%2F&data=05%7C02%7Ctoddz%40pgrahamdunn.com%7C > 121f298cb > >>> > 3e14f03b9bd08dc5d903f9c%7C5758544c573f47cebee96c3e0806fb43%7C0%7C > 0%7C > >>> > 638488121334286091%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwM > DAiLCJQIj > >>> > oiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=r%2 > FbS%2B > >>> > r5ZzfMgSoGCoDw7i%2Fhf123ev8AZK3A9U5JtkFs%3D&reserved=0%2Findex. > php&da > >>> ta=05%7C02%7Ctoddz%40pgrahamdunn.com > >>> > %7Cc87909c9a4b6452a9e7008dc5d83f6a5%7C5758544c573f47cebee96c3e080 > 6fb4 > >>> 3 > >>> > %7C0%7C0%7C638488068569795566%7CUnknown%7CTWFpbGZsb3d8eyJWIj > oiMC4wLjA > >>> w > >>> > MDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C > &sdata > >>> = > %2BkgiY%2FC9l6%2BqT2O6bnpxqPKur7Myu6%2BaULa01B910Ck%3D&reserv > ed=0> > >>> 630 Henry Street > >>> Dalton, Ohio 44618 > >>> Phone: (330)828-2105ext. 2031 > >>> > >>> > >>> _______________________________________________ > >>> Emc-users mailing list > >>> Emc-users@lists.sourceforge.net > >>> > https://nam04.safelinks.protection.outlook.com/?url=https%3A%2F%2Flis > >>> > t%2F&data=05%7C02%7Ctoddz%40pgrahamdunn.com%7C121f298cb3e14f03 > b9bd08d > >>> > c5d903f9c%7C5758544c573f47cebee96c3e0806fb43%7C0%7C0%7C638488121 > 33429 > >>> > 2888%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2lu > MzIiLCJB > >>> > TiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=Abfy%2FAQizwNK > uInKClxa2 > >>> Ztuzys0e49UuGdGw5o%2B9hI%3D&reserved=0 > >>> s.sourceforge.net%2Flists%2Flistinfo%2Femc- > users&data=05%7C02%7Ctoddz > >>> % > >>> > 40pgrahamdunn.com%7Cc87909c9a4b6452a9e7008dc5d83f6a5%7C5758544c5 > 73f47 > >>> c > >>> > ebee96c3e0806fb43%7C0%7C0%7C638488068569804807%7CUnknown%7CT > WFpbGZsb3 > >>> d > >>> > 8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0% > 3D%7 > >>> C > >>> > 0%7C%7C%7C&sdata=sb3DbNBIrWxq9OqYRv32Q6KHka%2FvXqAzp1QV8vF5E > eA%3D&res > >>> e > >>> rved=0 > >>> > >> > >> Peter Wallace > >> Mesa Electronics > >> > > > > Peter Wallace > > Mesa Electronics > > > > Peter Wallace > Mesa Electronics > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users
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