Logix 5000 with kinetix 2000

I was wondering if it was possible to move a servo based on an external encoder feedback.

Im using a kinetix 2000 serco drive. The servo has a built in encoder. The servo is connected to a 100:1 gear reducer. There is an arm connected to the reducer. The arm has a total rotational movement of about 45 degrees. An external encoder was attached to the pivot point on the arm, which is really the output of the 100:1 gear reducer. We ended up using an external enecoder due to gear backlash in the reducer. This needed to be a very accurate application. So my question is, How can I move my servo based on an auxiuary external encoder as oppossed to the servo internal encoder.

yes it is possible. I haven't done that with the kinetic drives. You should be able to set the aux. encoder up as the master axis and gear the real drive to the with a MAG instruction.

Research the Loop Configuration for the servo in RSLogix 5000

Especially Dual Position Servo and Auxiliary Dual Command Servo

In these loop configurations there are 2 feedback devices -
One motor mounted for commutation
The auxiliary for Positioning accuracy after your gear reducer

My preference is to use the "Dual Position Servo"