Labview/arduino appears to slow motor down

[GGT91]

Hello,
Relatively new to all of this but here goes:
I have:
Arduino Duemilanove
RSSM2 Stepper Driver card.
Astrosyn Y129 Stepper Motor

I have connected it all up and written a program in labview to control it. All seems to be working, however I notice I get a very small maximum speed from the motor. When I disconnect the arduino, and use the RSSM2's internal clock (by shorting the step rate input to the output) I can control the speed by the variable resistor. This gives a much greater max speed.
Is it the arduino that is slowing the speed down?
Or labview?

Any help appreciated.

Basically all i'm doing is sending high signals to the input via a labview loop. Another high/low signal controls direction and a high signal goes to the DIS input when my loop is complete, which in turn shuts off the motor.

[Kristoff2 · Accepted solution]

Are you using Digital writes to set the pins high / low to generate the 'clock' signal that controls the motor speed.  If you are the loop rate will be <200 Hz (maybe <100 depending on what you are doing in LV).

What you really need to do is generate a square wave output at variable frequency using hardware rather than LV.  This can be accomplished using the Tone VI.

Post back if you have follow up questions (or if my assumptions were not correct and the above was not relevant).

-Sam K

LIFA Developer