HOME  |  NEWS  |  BLOGS  |  MESSAGES  |  FEATURES  |  VIDEOS  |  WEBINARS  |  INDUSTRIES  |  FOCUS ON FUNDAMENTALS
REGISTER   |   LOGIN   |   HELP
<<  <  Page 2/2
ttemple
User Rank
Platinum
Re: WHy not proper shielding?
ttemple   8/14/2012 1:34:23 PM
NO RATINGS
While it doesn't explicitly state it in the article, it appears that the encoders in question have single ended outputs.  It appears that the extenders convert the signals to differential mode, which is much more noise tolerant.  Shielding is a good idea, but with single ended signals I doubt it would have been enough if there is serious high frequency switching noise all around.

kf2qd
User Rank
Platinum
WHy not proper shielding?
kf2qd   8/14/2012 11:30:30 AM
NO RATINGS
Having built and serviced CNC plasma cutting machines, proper shielding of cables does wonders. The comercial products we used all had shielding built into the harness to keep the noise out. And the shields were always grounded at 1 end only., and in some cases where the design was older and more sensitive they actually had 2 shields, insulated from each other and each one grounded at opposite ends of the cable.

Also - effort should be made to seperate the motor and encoder cables. Often just having them shielded and a few inches apart is sufficient.

GlennA
User Rank
Gold
ground loop ?
GlennA   8/14/2012 11:07:31 AM
NO RATINGS
You mention using shielded cables.  Did you ground only one end of the cable shield ?  I have seen installations with both ends of the cable shield connected to ground, which makes ground loops a concern.

naperlou
User Rank
Blogger
Shorter signal path
naperlou   8/14/2012 9:02:24 AM
NO RATINGS
I was wondering, as I was reading the article, why you did not look at shortening the signal path.  I can think of reasons, but I am wondering what the situation is in this case.

<<  <  Page 2/2


Partner Zone
Latest Analysis
Eric Chesak created a sensor that can detect clouds, and it can also measure different sources of radiation.
Festo's BionicKangaroo combines pneumatic and electrical drive technology, plus very precise controls and condition monitoring. Like a real kangaroo, the BionicKangaroo robot harvests the kinetic energy of each takeoff and immediately uses it to power the next jump.
Practicing engineers have not heeded Yoda's words.
Design News and Digi-Key presents: Creating & Testing Your First RTOS Application Using MQX, a crash course that will look at defining a project, selecting a target processor, blocking code, defining tasks, completing code, and debugging.
Rockwell Automation recently unveiled a new safety relay that can be configured and integrated through existing software to program safety logic in devices.
More:Blogs|News
Design News Webinar Series
3/27/2014 11:00 a.m. California / 2:00 p.m. New York / 7:00 p.m. London
2/27/2014 11:00 a.m. California / 2:00 p.m. New York / 7:00 p.m. London
12/18/2013 Available On Demand
11/20/2013 Available On Demand
Quick Poll
The Continuing Education Center offers engineers an entirely new way to get the education they need to formulate next-generation solutions.
Apr 21 - 25, Creating & Testing Your First RTOS Application Using MQX
SEMESTERS: 1  |  2  |  3  |  4  |  5


Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.
Next Class: April 29 - Day 1
Sponsored by maxon precision motors
Learn More   |   Login   |   Archived Classes
Twitter Feed
Design News Twitter Feed
Like Us on Facebook

Sponsored Content

Technology Marketplace

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
Copyright © 2014 UBM Canon, A UBM company, All rights reserved. Privacy Policy | Terms of Service