On May 27, 2012, at 7:39 AM, Jan de Kruyf wrote: > That is a bit of a difficult configuration. I rather like to us > encoders with a RS485 balanced pair output i.e. A, notA, B, notB, etc. > The receivers reject noise much better in htat configuration.
I actually wired up a differential encoder/decoder a few days ago and it actually made the drive more noisy so I removed it and am currently using double shielded cable instead. In retrospect, I don't think the problem was with the differential signals, I think instead it was some kind of interference inside the enclosure which I think I now have resolved... > You might try to find a powder iron or ceramic ring-core and loop all > encoder wires through a few times close to the computer. Or perhaps > find some rf suppressor beads as used on VGA monitor signal cables. > The idea being that what goes in must come out. and the influence of > stray fields on the encoder cable is rejected by the core. Nice idea! > Other than that: run the encoder cable seperate from the motor power > cable. Earth all screening on one side only. Normally the > computerside, at the enterance into the steel computer cabinet. Yes, that is currently how it is. > And yes take the 2 motor power wires, clamp them into the drilling > machine chuck and twist them. It is very important. Thank you for that, I have done that for most of the power wires now, and I will do it for the rest. Should it be done even to the motor wires outside of the enclosure and far from any signal cables? > In desperation over and above all this you might try to implement > small LC filters on each signal wire. > I dont have any values off my head. If needed I can look them up. Thanks for all your helpful suggestions Jan! Best, Jeshua Lacock Founder/Engineer 3DTOPO Incorporated <http://3DTOPO.com> Phone: 208.462.4171 ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
