unable to drive stepper motor

[Syphonics]

I have a problem with my vexta stepper motor. Using the PIC16f877, I could run the motor. But using the keyence kv-40DR I am unable to do so. The motor moves forward and backwards, kind of weird movement.
The programming is almost the same. Same pulse inputs and etc. I have tried with different driver and even motor. But same results.
The only difference is the PIC16f877 is a transistor relay and the kv-40DR is a normal relay PLC.
Is that the cause of the problem?

[vger]

Normal relays tend to have contact bounce. When the armature of the relay moves to close the contacts, the contacts actually strike and bounce making multiple very short connections before connecting firmly. This would not be a problem for controling a solinoid valve or a light. The logic inputs of a stepper motor driver will see the multiple pulses and act erraticly.

Steve

[Syphonics]

Originally Posted by vger Normal relays tend to have contact bounce. When the armature of the relay moves to close the contacts, the contacts actually strike and bounce making multiple very short connections before connecting firmly. This would not be a problem for controling a solinoid valve or a light. The logic inputs of a stepper motor driver will see the multiple pulses and act erraticly. Steve

Thanks Steve,

Finally I am enlighten on this weird issue.