On 08/10/2017 11:09 AM, Les Newell wrote:
I have been chasing a noise problem on my lathe for some time now. I
am using a 7i29 2kw drive and am getting a lot of noise on the
encoders, even with filtering enabled at a pretty low frequency. I
have tried just about everything I can think of. I made a simple
near-field probe and did a bit of poking around. The 20kHz drive
switching noise was strong pretty much everywhere. After trying
various things I found a common mode choke on each motor output
dropped the 20kHz noise down so it was pretty much undetectable apart
from right next to the chokes. However I am still getting noise on the
encoders. I have a spare encoder input on a 7i33 so I moved one of the
motor encoders to that input. I am getting zero noise on that channel
even though I extended the encoder cable to reach the 7i33 with 6
individual wires instead of a screened cable. Even with filtering
disabled I see no noise. Unfortunately I don't have any more spare
encoder inputs for the other axis.
Has anyone else had noise issues with 7i29 drives?
Les
My CHNC uses a 7I29 and a single end encoder on the X axis, works fine.
All the wiring goes through the same flex guide. Make sure your motor
leads are twisted to cut the noise.
Ed.
------------------------------------------------------------------------------
Check out the vibrant tech community on one of the world's most
engaging tech sites, Slashdot.org! http://sdm.link/slashdot
_______________________________________________
Emc-users mailing list
Emc-users@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/emc-users
