It has differential A and B channel inputs and 12 v power to the encoder On Sat, May 2, 2020 at 4:36 PM andrew beck <[email protected]> wrote:
> hey gene > > I have the push pull output standard encoder card not the sin cos encoder > card. it is the left diagram in the pdf not the one on the right. > > regards > > Andrew > > On Sat, May 2, 2020 at 4:31 PM Gene Heskett <[email protected]> wrote: > >> On Friday 01 May 2020 22:19:57 andrew beck wrote: >> >> > I found this explanation of what a push pull output is.. >> > >> > https://www.dynapar.com/knowledge/encoder_output/ >> > >> > still doesn't make that much sense but I am sure it will all come >> > together. >> > >> > On Sat, May 2, 2020 at 2:14 PM andrew beck <[email protected]> >> wrote: >> > > Hi guys >> > > >> > > me again >> > > >> > > I have just received my schiender vfd encoder card from ebay for my >> > > spindle encoder feedback to linuxcnc >> >> That card has inputs labeled +, - cos and +, - sin. So its expecting >> signals from a resolver, not an 1000 ppr encoder, which is not at all >> compatible with any 1000 ppr digital encoder regardless of its possible >> differential outputs in the digital domain. >> >> To receive and decode the 1000 line encoder you will need a "quadrature" >> encoder which will also have that missing index pulse. >> >> A resolver is an analog device consisting of an exciter winding driven >> from the +- ref terminals on that card, and which induces a voltage in >> two crossed at 90 degree coils such that the induced voltages coming >> back to the cos and sin terminals can be measured, and the actual >> position calculated from that, returning the position in degrees or >> radians, and zero degrees then is usually considered the index. But you >> could drive either to any position a tool changer might need. Most would >> drive it past that point a few counts, drop a pawl to stop it and back >> it up against the pawl to get the position accuracy needed. >> >> Its more accurate in that the answer is never quantized into 1/4000 of a >> turn which is what the 1000 ppr encoder would do. Depending on the >> electronics, the resolver could be slightly slower settling, and its >> always more expensive. >> >> > > I was just looking at it and it seems the encoder card only has >> > > differential A and B inputs- It doesn't have a index counter. >> > > >> > > obviously to make the spindle orientation work I need to be able to >> > > read the index pulse from the encoder. I was thinking maybe the >> > > best way to do this would be to get a ENCY mesa board and connect my >> > > encoder to that. then connect the one of the outputs from the board >> > > to linuxcnc encoder counters. the other split output can go to the >> > > vfd for closed loop control inside the vfd >> > > >> > > (I will only use the A and B pulses inside the vfd.) >> > > >> > > My vfd supports closed loop control if I have can get the encoder >> > > counting back into the vfd and I will get 200 percent of the full >> > > torque at 0 rpm which is pretty cool. It should be almost like a >> > > servo. >> > > >> > > does this all seem like a good idea to people? >> > > >> > > and has anyone ever used the ENCY mesa card? I am not sure how to >> > > power it. Eg do I power it from my mesa card encoder 5v or from the >> > > vfd . I guess I can't power it from both. >> > > >> > > this is the encoder card I have. needs to be used with a 12 v >> > > encoder. the max hz is 300khz which I calculated at 1000ppr allows >> > > me a max speed of 18000 rpm. I can get a 1000ppr encoder from my >> > > chinese servo supplier that allows up to 10k rpm which is what my >> > > max spindle speed is. and I think I can get a 12 v version. I am >> > > not sure what push pull outputs are though. >> > > >> > > >> > > https://www.se.com/nz/en/product/VW3A3405/encoder-interface-card-wit >> > >h-push-pull-outputs---12-v-dc/ >> > > >> > > >> > > and a pdf that shows the connections >> > > >> > > VW3A3405 ENCODER CARD >> > > <https://download.schneider-electric.com/files?p_enDocType=Instructi >> > >on+sheet&p_File_Name=1755538.pdf&p_Doc_Ref=1755538> >> > > >> > > regards >> > > >> > > Andrew >> > >> > _______________________________________________ >> > Emc-users mailing list >> > [email protected] >> > https://lists.sourceforge.net/lists/listinfo/emc-users >> >> >> 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) >> If we desire respect for the law, we must first make the law respectable. >> - Louis D. Brandeis >> Genes Web page <http://geneslinuxbox.net:6309/gene> >> >> >> _______________________________________________ >> Emc-users mailing list >> [email protected] >> https://lists.sourceforge.net/lists/listinfo/emc-users >> > _______________________________________________ Emc-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/emc-users
