[novacustard]

Following on from my earlier posts, I have sorted some of the problems.
Background: My XYZ system is built around a Parker 6K4 controller, Parker OEM770T servo drives and uses a Parker Compumotor SE230AEKFLG10 10:1 geared servo motor on the X & Y axis, and a Compumotor SE232BE servo on the Z axis.
I had problems when trying to tune the X & Y servos, the X axis suffering fro noise, the Y axis basically would move a fraction (no more than 10°) then stop.
Swapping the X axis motor for the Y axis one just moved the problem to the X axis.
Checking the wiring back to the motor showed no difference between the two.
Checking the encoder/position output showed that the encoder was not behaving - the encoder count would not increment correctly.
Based on this I took the encoder off a spare SE232AE motor (the encoder is the same spec although a slightly different model, and has the same wire outputs as the suspect one).
The Y axis geared motor now has a functioning encoder, (note, the encoder also outputs the hall state for the motor). However, as the attached picture shows, the response to a commanded position is the reverse from what would be expected.
I have double checked and cheacked again the wiring, and the motor power connections, hall and encoder connections are all correct.
Swapping two motor phase wires over just locks the motor.
The motor turns in the opposite direction to commanded, and does not turn the correct distance (ie, a commanded CW move of 20000 counts (180°) results in a CCW move of around 15°).
I've pretty much given up on this motor, but it is a shame.
Can anybody suggest any possible causes, tests or solutions (other than a new motor!).
Many thanks,

Richard.