Peter posted this before. Yes, the encoder is the RS58-O/500EK.42KB i.e. 'K' version.
Go to https://uk.rs-online.com to get to the data sheet. His is the push pull variety. John > -----Original Message----- > From: Chris Albertson [mailto:albertson.ch...@gmail.com] > Sent: October-10-21 6:59 PM > To: Enhanced Machine Controller (EMC) > Subject: Re: [Emc-users] Fwd: Rogue Index Pulses > > sorry there was no part number on the encoder. I figured it was the generic > Omron clone that is 5 to 12 volts. But there are two kinds that other is > 12 to 24. volts. See in the link below > https://www.ia.omron.com/products/family/486/specification.html > > Is the encoder "open collector" or voltage output. If open colector pull > the outputs up to 5 volts. > > Placing an encoder part number of the schematic would help. > > Can you post a picture of "ghost pulses", if using an analog scope just use > you phone camera, most digitalscopes can save the scree to USB drive. > Noise like this is best eliminated at the source > > > On Sun, Oct 10, 2021 at 1:04 PM Peter Hodgson <peterjohnhodg...@gmail.com> > wrote: > > > Hi Chris, > > > > The encoder datasheet gives a voltage range of 10-30vdc so I don�t think > > direct connection with 5vdc would be an option. > > > > Would a direct connection via voltage dividers eliminate the �ghost > > pulses� being picked up by the Pico board? > > > > The encoder won�t be running above 3,000 rpm. > > > > Pete > > > > > On 10 Oct 2021, at 19:00, Chris Albertson <albertson.ch...@gmail.com> > > wrote: > > > > > > ?Is your math right? Yes, I get 83 KHz for a 500 line encoder at 10,000 > > > RPM. Yes that is < 1% of the isolator's rated speed (of 10 MHz) > > > > > > But the schematic had an RC low pass filter in the encoder output that > > > would have prevented the system from working above about 1000 RPM. I see > > > this is gone now. > > > > > > But why are these isolators even needed? Why not simply operate the > > > encoder at 5 volts? > > > > > > Or if you must run the encoder at 12 volts, you can do level translation > > > with a resistor voltage divider. > > > > > > There is nothing yo isolate. The entire system runs on a common ground > > and > > > there is no high power devices in the schematic and I assume the entire > > > system is in one building with no long (100 meter) cables > > > > > > If you are worried about accidents blowing up the controller, use diodes > > to > > > shunt any transients. But really there are no inductive loads > > > > > > > > > > > > > > > > > > On Sun, Oct 10, 2021 at 10:25 AM John Dammeyer <jo...@autoartisans.com> > > > wrote: > > > > > >>> From: Gene Heskett [mailto:ghesk...@shentel.net] > > >> > > >> > > >> > > >>> If the opto's are fast enough, you should be > > >>> fixed. A 500 ppr encoder s/b fine. A 1024 or 1000 requires a faster > > >>> opto. > > >>> > > >> > > >> HI Gene, > > >> Comparing the cheap far east BoB optos with the HCPL2621 is apples and > > >> oranges. > > >> > > >> A 2500 line encoder still only creates 2500 pulses. The quadrature just > > >> looks at two lines and 2 edges for 10,000 edges. But the max speed of > > his > > >> encoder is 10,000 RPM which in RPS is 166.7 and would result in 417kHz > > >> which is 4% of the opto max 10 Mbps capabilities if the encoder was > > 2500 > > >> line. > > >> > > >> But his is 500 line so at 166.7 RPS is 83kHz which is 0.8% of opto > > >> capabilities. > > >> > > >> > > >> John > > >> > > >> > > >> > > >> > > >> _______________________________________________ > > >> Emc-users mailing list > > >> Emc-users@lists.sourceforge.net > > >> https://lists.sourceforge.net/lists/listinfo/emc-users > > >> > > > > > > > > > -- > > > > > > Chris Albertson > > > Redondo Beach, California > > > > > > _______________________________________________ > > > 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 > > > > > -- > > Chris Albertson > Redondo Beach, California > > _______________________________________________ > 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
