On Tuesday 06 October 2009, Steve Blackmore wrote: >On Sun, 04 Oct 2009 23:46:48 -0500, you wrote: >>Steve Blackmore wrote: >>> Hi Jon >>> >>> Encoder is connected to a couple of UA9637ACP differential line >>> receivers. I'm putting A+ A-, B+ B-, I+ I- in and getting A, B, I out at >>> 3.5V, should I connect the resistors on the outputs of the line >>> receiver? >> >>Oh, my! This is getting messy, for sure. Possibly you do need the >>pullups on the >>9637 outputs. You can certainly try that. Also, do you have >>terminators on the differential >>lines coming into the receiver? If not, there will be a lot of ringing >>on every state transition. >>I usually put a 120 Ohm resistor across the inputs of the line receiver. > >Hi Jon - tried 120 Ohm across the inputs - it stopped the line receiver >working?
Oh. Dear. My. Those are either bad encoders, or you have a short to ground on one of the two lines from each track of the encoder. If you put a digital meter on the A+ and A- lines, with one lead on ground there should be a full TTL swing on both lines w/o that resistor, and if you read from A+ to A- with the resistor, it should alternate polarities and have a difference of at least 50 millivolts on both polarities as you move the encoder very slowly. Where are you physically at Steve? Within a days drive of me perchance? I'm in north central WV, USA. >The pull ups on the outputs helped marginally but it's much >better than it was and is quite usable. I'll order some better encoder >cable and will try and rewire. > > >Steve Blackmore >-- > >--------------------------------------------------------------------------- >--- Come build with us! The BlackBerry(R) Developer Conference in SF, CA is > the only developer event you need to attend this year. Jumpstart your > developing skills, take BlackBerry mobile applications to market and stay > ahead of the curve. Join us from November 9 - 12, 2009. Register now! > http://p.sf.net/sfu/devconference >_______________________________________________ >Emc-users mailing list >Emc-users@lists.sourceforge.net >https://lists.sourceforge.net/lists/listinfo/emc-users > -- Cheers, Gene "There are four boxes to be used in defense of liberty: soap, ballot, jury, and ammo. Please use in that order." -Ed Howdershelt (Author) The NRA is offering FREE Associate memberships to anyone who wants them. <https://www.nrahq.org/nrabonus/accept-membership.asp> Satellite Safety Tip #14: If you see a bright streak in the sky coming at you, duck. ------------------------------------------------------------------------------ Come build with us! The BlackBerry(R) Developer Conference in SF, CA is the only developer event you need to attend this year. Jumpstart your developing skills, take BlackBerry mobile applications to market and stay ahead of the curve. Join us from November 9 - 12, 2009. Register now! http://p.sf.net/sfu/devconference _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
