Loss of encoder counts ¡ ¡

[molocas]

Hello everyone ¡ ¡
I am starting in using a geckodrive G320X to run servo motors from an old HP plotter
7475A , As I can see, the encoder of this motor is a cuadrature one with 500 steps
so geckodrive counts 2000 steps per revolution. I use a pic 12f683 to send pulses
and change direction of rotation.
The thing is, the lowest speed the more error I have so I try diferent speeds.
I can see better performance at medium to high speed but any way I lost position
if I leave the motor running for a long time.
Y put two marks, one in rotor and one in motor to see if motor shaft returns to this marks after few turns forwarding and reversing the motor.
I have tried differents ways, adding a small delay after change direction of rotation, decreasing speeed before reach the mark , but same thing, l lose position.


I hope someone can help me if I am doing things wrong
Regards
Molocas

[RodSTAR]

If you haven't already solved your problem, these tips may help, otherwise you could tell how you solved it.
Have you tested if your mini pic outputs your desired pulses? And if your g320 receives all sent pulses? Is each pulse the enough width (duty time) that g320 can understand? Did you check encoder multiplier setting pins on your g320? It smells to me like something with encoder settings