controlling step motors without a driver

[kd315]

I am trying to create a VI in labview that will control a step motor, but I don't have a driver for the motor. I am wondering if this is possible and if so, how would I go about doing that.  Thanks in advance for the help

[AnalogKid2DigitalMan]

"Driver" in the terms of software, or 'driver' in the terms od electronics hardware to apply power to the motor?

 Please provide more details.

[kd315]

I don't think that I have a software or hardware driver. I hope that helps.

[Jochen]

Please tell us what kind of hardware interface you are planning to use and what kind of motion control you want to do (velocity control, position control, 1D, 2D, 3D, interpolation modes,...). What type of application do you want to build?
Without this information the only thing we can do is guessing...

Best regards,

Jochen Klier
National Instruments Germany

[Buechsenschuetz]

None of the NI boards can drive a stepper motor directly. You always need a device to supply the power and the phase-shift excitation signals to the stepper motor windings.

Stepper motor power drivers are available in lots of different varieties - from NI as well as from other manufacturers. Usually it is not a big problem to generate the driver control signals in the PC, whether you use a dedicated motion controller or not. But the driver also has to match the motor you are using - there are parameters like current, motor coil wiring etc. Without data on the motor (and system) you are going to use it is not possible to give any recommendations.

[kd315]

ok, the hardware that I have is a slow-syn stepping motor connected into a keithley PCI board. All I need to be able to do is create an interface where the user can enter a specific distance for the motor to move, and that distance can be converted into a voltage and output to the stepper motor. I hope that clarifies what I am trying to do.

[Buechsenschuetz]

I have heard that Keithley makes some PCI boards which can drive low-power stepper motors directly.

I am everything but familiar with LabView and its (possible) support of Keithley stepper motor boards. But a stepper motor driver does not output a voltage. It sends a two-phase power signals to the motor windings. The motor specs will tell you how far the motor turns with one step (e.g. a motor with 200 full steps per revolution will turn 360 deg / 200 = 1.8 deg when driven with one full step.

However, since you do not seem to be very familiar with stepper motor basics, I would recommend to make a Google search for 'Jones on stepping motors'.

http://www.cs.uiowa.edu/~jones/step/

Mr Jones has written an excellent tutorial for stepping motors. Possibly something similar exists on the NI website - oops, it does exist:

http://zone.ni.com/devzone/conceptd.nsf/webmain/6857fe332d81753586256e6800777e84

http://zone.ni.com/devzone/conceptd.nsf/webmain/786DCA29F029AE588625688600517B15#1