Hello.
I have acquired some NanoStep Vexta drives model DFR1514A which are same as RFK series of NanoStep drives.
http://www.orientalmotor.com/product..._B163-B174.PDF

I was able to hook up a StepSyn stepper motor type 103H7853-8053
The drive powers up and the winding energize.
The drive is in 1 pulse mode, meaning that is uses Step (or pulse 'PLS' in this drive) and direction input (CW/CCW)
The documentation proposes that a transistor is used to ground the PLS- signal while PLS+ is feeded +5V.
The motors jerks if I use a resistor and ground the PLS- signal, so I guess the drive is kind of functional.

I made a simple circuit using a BC547 general purpose transistor. Base to STEP from BOB, Emitter to GND and Collector trough a 1k resistor to the drive's PLS- signal.

And it didnt worked out.
Of course my electronic skills are very moderate.

Mach3 has 5us on pulse length.
The BOB is functional and using other drives it do turns my bipolar steppers.

There is a dip switch labeled ACD and I don't know what is does, I had it on both positions with same results.

I believe it is worth mentioning that the drive connector colors for the stepper are Black,Green,Orange,Red and Blue. My steppers however have Blue, Red, Orange, Yellow and Black. I matched all the colors except for Green-Yellow.

Thanks for the help.
Konstantin.