Controlling a stepper motor with a PLC

[johnny25]

I'm trying to generate the pulses to control a NEMA 17 stepper motor with a PLC.

The motor has a driver that converts the pulse/direction signals into the correct A and B phase signals for the motor. I programmed the PLC to output a series of pulses on an output pin to move the motor. The problem is that when the motor makes a stepping motion, it makes loud noises, like it's shaking violently. Also, the motor turns a few steps in one direction and then either misses a step or two or turns a few steps in the opposite direction. I left the DIR signal as is.

I've read about acceleration and deceleration ramps to keep the motor running smoothly and initially thought this might be the problem, although the same thing happens even if I only send a pulse to the driver every second or two. So for a single step motion, there is no possible acceleration/deceleration ramp (right??).

I have tested the same stepper motor and driver with a PC controlled system (running Mach3 software) and it runs smoothly and does not produce the noise or vibration I am getting during single step movements.

Any .???