MDC 2250 Closed Position control mode Problem.

I am using MDC 2250c for Postion control od DC motor.
Feedback encoder i am using is incremental counter.
problems i am facing are may be due to PID parameters.

1)I am giving a certain count using !PR 2 command the problem is that i am facing is that whnever the motor is just reaching to its destination motor start slowing down and just before reaching the count motor power start rising again and motor doesnot stop @ its destination.

2) in closed loop mode if i set the Position mode velocity greater than 500 with only Proportional gain .1 only motor does start rotatin in opposite direction and when i set the Position mode velocity to 1500 rpm with P Gain = 1.5,I gain =1 and D gain =0.1 motor works correctly but the rpm is always limited to 450 only where as i have tried to run the motor in open loop mode it can reach upto 2000 rpm.

Please reply asap

Which position mode are you using? Count position?

If you are using a closed loop position mode, you would use an absolute encoder as that is designed for position and the incremental is for speed.

In your closed loop parameters, you can set the max RPM velocity as that will determine your max RPM. Default for that value is 1000.