________________________________ From: [email protected] <[email protected]> Sent: Sunday, May 19, 2019 1:48 PM To: [email protected] Subject: Emc-users Digest, Vol 157, Issue 32 Send Emc-users mailing list submissions to [email protected] To subscribe or unsubscribe via the World Wide Web, visit https://lists.sourceforge.net/lists/listinfo/emc-users or, via email, send a message with subject or body 'help' to [email protected] You can reach the person managing the list at [email protected] When replying, please edit your Subject line so it is more specific than "Re: Contents of Emc-users digest..." Today's Topics: 1. Re: How come.... (Dave Cole) 2. Re: How come.... (Dave Cole) 3. Re: Unusual help request. (Peter C. Wallace) 4. Unusual help request. (Davide) 5. Re: Unusual help request. (Peter C. Wallace) ---------------------------------------------------------------------- Message: 1 Date: Sun, 19 May 2019 12:34:21 -0400 From: Dave Cole <[email protected]> To: [email protected] Subject: Re: [Emc-users] How come.... Message-ID: <[email protected]> Content-Type: text/plain; charset=utf-8; format=flowed I do have to wonder though... if these Tesla cells were no longer usable for a Tesla, why would anyone think they would be good in a stationary application unless they were derated by quite a bit. $1200 is far from free. Dave On 5/17/2019 12:24 PM, Kirk Wallace wrote: > > Here is a fairly common surplus Tesla module: > >> https://www.ebay.com/itm/262333679871 > > If these have have not been abused after they were removed from the > car they should last many thousands of deep cycles.? They are 6s but a > 7th s can be added in order to cycle them deeper on a common 24 volt > system. > > My system (single, living in an RV) is close to this except I am using > two Johnson Controls modules rewired as 7s: >> https://www.mobile-solarpower.com/tesla-solar-battery-diy.html >> https://www.ebay.com/itm/123187038180 > > This technology is changing so quickly that it is hard to keep current > and reviews become stale in a month or two. > > > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------ Message: 2 Date: Sun, 19 May 2019 12:42:48 -0400 From: Dave Cole <[email protected]> To: [email protected] Subject: Re: [Emc-users] How come.... Message-ID: <[email protected]> Content-Type: text/plain; charset=utf-8; format=flowed That's what I understood...? I won't be owning a Tesla until that changes. Dave On 5/18/2019 2:50 PM, Bruce Layne wrote: > Tesla has adopted the software > rental model where the customer doesn't really own anything. ------------------------------ Message: 3 Date: Sun, 19 May 2019 10:21:46 -0700 (PDT) From: "Peter C. Wallace" <[email protected]> To: "Enhanced Machine Controller (EMC)" <[email protected]> Subject: Re: [Emc-users] Unusual help request. Message-ID: <[email protected]> Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed On Sun, 19 May 2019, Nicklas Karlsson wrote: > Date: Sun, 19 May 2019 18:27:44 +0200 > From: Nicklas Karlsson <[email protected]> > Reply-To: "Enhanced Machine Controller (EMC)" > <[email protected]> > To: "Enhanced Machine Controller (EMC)" <[email protected]> > Subject: Re: [Emc-users] Unusual help request. > >> On Sun, 19 May 2019, Davide wrote: >> >>> Date: Sun, 19 May 2019 16:26:26 +0200 >>> From: Davide <[email protected]> >>> Reply-To: "Enhanced Machine Controller (EMC)" >>> <[email protected]> >>> To: [email protected] >>> Subject: [Emc-users] Unusual help request. >>> >>> Hi, I have a strange setup to solve. So I'm asking you an help, on the top >>> of your knowledge (sorry for any language mistake) Some time ago I have >>> built an inverted wire tetrapod, which was made by 4 winches placed at a max >>> distance of 20 meters one each other in a rectangular shape. So until now it >>> was ok to have a 48v 20A DC power supply and a parallel bob near my pc (an >>> asrock q1900b-itx), and transmit step/dir signals thru ethernet cables to >>> the stepper drivers inside the winches. >>> >>> Now I have to modify that to make a very little object fly inside a soccer >>> arena, so the motors will be placed at 80 meters one each other, and i'm >>> really worried that a step every 10 will arrive to the drivers, if any at >>> all.. The further motor will be at 150mt if I'm lucky.. >>> >>> An idea can be a mesa ethernet card, but I should use 4 of them, so I'm >>> asking you if you think is possible to make 4 of them work with linuxcnc? >>> >>> Another can be convert in some way step dir signals to optic fiber >>> transport. But i couldn't find anything to buy. >>> >>> Any other suggestion? >>> Thanks, Davide. >>> >> >> >> 150 meters is no problem for 100 KHz RS-422 (Spec is 1220 meters at 100 KBPS >> ~= 50K steps/second) So just using good line drivers/ receivers should be >> fine >> It may even work with differential drivers and normal opto-isolated step >> motor >> drives driven differentially > > You might also need terminators to avoid reflections. Yes, you probably need to know the drives optopcoupler input circuitry Many Chinese drives get this wrong (no reverse polarity protection diode across OPTO LED) In this case, an external reverse diode/resistor pair would handle the reverse direction oveshoot and prevent OPTO damage in the OPTO LED off direction Many drives have 220 ohm series resistors, this would result in less than 50% overshoot (for say 750 ns with 150 meters ) which should not be harmfull in the on direction > > > _______________________________________________ > Emc-users mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/emc-users > Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your (")_(") signature to help him gain world domination. ------------------------------ Message: 4 Date: Sun, 19 May 2019 19:33:51 +0200 From: Davide <[email protected]> To: [email protected] Subject: [Emc-users] Unusual help request. Message-ID: <[email protected]> Content-Type: text/plain; charset=utf-8 Hi, and thanks for your suggestions. ? The driver does support multiple ethernet cards (up to 4) so you could use a 7i92 (for example)? for each motor. Though even then 150m would be optimistic, I suspect. ?why? isn't it a standard ethernet? I can plug pc eth to a good gigabit switch and run 4 lines to the winches, or put 2 other switches around and amplify the signal. I also have in mind to use just one 7i92 near the pc, and build a ttl -> fiber optic converter using?SN75451?(two channel Logic + LED drivers) to drive some?HFBR1414?plugs, which claim to transmit up to 1500 mt (minimum 500mt) I have a tech question about 7i92. I have only run Lcnc using software step gen, but I understand that a 7i92 does step generation on its own, freeing the pc from doing the hard work. But what messages are sent from the pc? are they just POS/SPEED? and, since I have my untrivial kinematics, are they always done by the pc, right? when I run a latency test I have good results, something like Servo t. 2-3000 and Base t. 5-7000.? ?Is the 7i92 driver linked to the Servo, or Base Thread? what Latency time is it needed? and for 4*7i92? I'm sorry for all these questions, but unfortunately I don't have a lot o f time to experiment, so I need to clarify my mind, before buying a lot of things.. Thanks, Davide. ------------------------------ Message: 5 Date: Sun, 19 May 2019 10:47:50 -0700 (PDT) From: "Peter C. Wallace" <[email protected]> To: "Enhanced Machine Controller (EMC)" <[email protected]> Subject: Re: [Emc-users] Unusual help request. Message-ID: <[email protected]> Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed On Sun, 19 May 2019, Davide wrote: > Date: Sun, 19 May 2019 19:33:51 +0200 > From: Davide <[email protected]> > Reply-To: "Enhanced Machine Controller (EMC)" > <[email protected]> > To: [email protected] > Subject: [Emc-users] Unusual help request. > > Hi, and thanks for your suggestions. >>The driver does support multiple ethernet cards (up to 4) so you could use a >>7i92 (for example) for each motor. Though even then 150m would be >>optimistic, >>I suspect. > > why? isn't it a standard ethernet? I can plug pc eth to a good gigabit switch > and run 4 lines to the winches, or put 2 other switches around and amplify > the signal. > Standard Ethernet maximum length is 100M > >I also have in mind to use just one 7i92 near the pc, and build a ttl -> >fiber >optic converter using SN75451 (two channel Logic + LED drivers) to drive some >HFBR1414 plugs, which claim to transmit up to 1500 mt (minimum 500mt) > Fiber optics is not needed unless you have MHz step rates, RS-422 differential should be fine up to a few hundred KHz step rates, and may not even need any added hardware other than chosing a BOB with differential outputs and possible reverse polarity protection if you are using low end drives > >I have a tech question about 7i92. I have only run Lcnc using software step >gen, but I understand that a 7i92 does step generation on its own, freeing >the pc from doing the hard work. But what messages are sent from the pc? are >they just POS/SPEED? and, since I have my untrivial kinematics, are they >always done by the pc, right? Yes, speed sent, current position returned, all position/velocity calculations done in LinuxCNC, but if you can get the desired step rates from your parallel port, you may not need a 7I92 and just need differential drivers at the BOB end for the paralle port generated step/dir signals > >when I run a latency test I have good results, something like Servo t. 2-3000 >and Base t. 5-7000. Is the 7i92 driver linked to the Servo, or Base Thread? >what Latency time is it needed? and for 4*7i92? > The 7I92 uses a servo thread only and requires a Preempt-RT kernel (the Stretch test ISO is the easiet way to do this) > >I'm sorry for all these questions, but unfortunately I don't have a lot o f >time to experiment, so I need to clarify my mind, before buying a lot of >things.. > > >Thanks, Davide. Peter Wallace Mesa Electronics (\__/) (='.'=) This is Bunny. Copy and paste bunny into your (")_(") signature to help him gain world domination. ------------------------------ ------------------------------ Subject: Digest Footer _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users ------------------------------ End of Emc-users Digest, Vol 157, Issue 32 ****************************************** _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
