MITSUBISHI FX-1N-24 MT PLC for servo drive programming instructions

Hi, all friends, I am developing an slicer machine program, where servo drive has to move 20 mm (whatever is set on hmi) distance and again it should stop for some time and then keep on continuing the process. i have mitsubishi fx-1n-24 mt PLC. for movement of servo i am using PLSY {S1 S2 Y0} instruction, where i set S1=k50 , S2= K30000 , Could you help me to understand that how can i increase the speed of my servo motor, which is connected to DELTA SERVO Amplifier ASDA-B2. my motor moves very slowly, i need it to run faster, how can i increase the servo motor at high speed, what values i should vary in PLSY.
is there any other instruction for servo movement in MITSUBISHI PLC PROGRAM.
Please guide urgently.
Big thanks in advance, Hind

more information.

i have used Y0 and Y1 output of PLC, for forward and reverse direction of servo.drive movement everything is ok. only need some speed increment.
when my motor is moving some sound is coming from motor.