My suggestion: Use ethernet to optical fiber: https://www.fs.com/products/35333.html is $23. An SX module https://www.fs.com/products/11774.html is $6.00. Off hand, I don't know how much the fiber costs, but it's cheaper than copper.
I've purchased these from fs.com and they are helpful and easy to deal with. Ken On Sun, May 19, 2019 at 1:22 PM Peter C. Wallace <p...@mesanet.com> wrote: > On Sun, 19 May 2019, Nicklas Karlsson wrote: > > > Date: Sun, 19 May 2019 18:27:44 +0200 > > From: Nicklas Karlsson <nicklas.karlsso...@gmail.com> > > Reply-To: "Enhanced Machine Controller (EMC)" > > <emc-users@lists.sourceforge.net> > > To: "Enhanced Machine Controller (EMC)" <emc-users@lists.sourceforge.net > > > > 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 <77...@tiscali.it> > >>> Reply-To: "Enhanced Machine Controller (EMC)" > >>> <emc-users@lists.sourceforge.net> > >>> To: Emc-users@lists.sourceforge.net > >>> 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 > > Emc-users@lists.sourceforge.net > > 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. > > > > _______________________________________________ > Emc-users mailing list > Emc-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/emc-users > _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
