what hardware for stepper motor control?

[heepofajeep]

Hi, I am wondering what hardware I need to control a stepper motor?  I currently have a motor driver that receives ttl pulses is terms of step & direction.  Currently I am using a Ni-usb 6501, but this is insufficient as it requires Labview to dictate the timing, which is insufficient for the 3.7 khz frequency that I require. 

I need to buy another DAQ which will receive analog inputs anyway, so I am just wondering if there is one I can buy that will have a pulse controller as well?  Also, I need to be able to increase & decrease the frequency on the fly [I have to be able to accelerate & decelerate the motor]. 

Thank you very much!

[chutla]

Your stepper motor most likely will need a driver made specifically for it.  I wouln't try mixing and matching here.  (I've worked a lot with Dragon Drivers, which interface well with Labview, but I still had to have the right driver for the motors I was using.)   Most of your stepper motor drivers have internal test modes, or a means of "talking" to them via a standard serial port.   Make sure you can get it working properly this way before you turn it over to Labview.

We need a bit more information.


Eric

[Jason N]

Hello,

NI does have PCI Motion Controllers that interface directly with motor drivers.  These Motion Controllers allow you to output step and direction pulses and also gives you analog input and output channels as well.  These controllers use the NI-Motion driver and gives the ability to change the acceleration and deceleration in your program along with many others.  You can find out more about the NI-Motion software and Motion Controllers at www.ni.com/motion.  If portability is a special requirement for you, then there are definitely motion setups out there with the controller, driver and motors packaged together that you can communicate with serially.

Jason N 

[sushma]

Hi ,

I have a 6- wire stepper motor with which I am trying to control the speed of the stepper motor using PWM and NI ELVIS .The specs for this DC synchronous/stepping motor are

type:M062-FD-419 ,

4.2V,

1.9A 

Class B INSULATED

 Spec. BM101025 Cont. Duty

200 steps per rev.

Can you please suggest a driver for this motor......?

[Kevin_Price]

the M062 designation *sounds like* it may be a Superior Electric "Slo-Syn" stepper.  S.E. got bought out some years back by Warner and there may have been another ownership change since.

In any event, the 6 leads very likely indicates a unipolar motor so you'll want to match that up with a unipolar drive.  On a unipolar motor, each winding leg has 3 taps -- 1 in the middle and 2 more at the ends.  Current always flows in the same direction down the center lead (hence the "uni").  Of the end leads, only 1 is switched ON at a time while the other is OFF.

In non-trivial apps, you'd typically need more info to select the right motor / drive combo (motor torque / speed curve, application loads, motion profiles, current vs. voltage drive, etc.) 

Also note that most stepper drives would expect a frequency pulse train and a direction bit rather than a PWM control signal.

Finally, if the app is fairly trivial, you can probably drive the motor with a 2-phase bipolar drive if you connect it right.  "Right" would mean to drive across the 2 windings end taps OR drive across 1/2 of each winding.  Rotation direction can be modified by simply reversing polarity on one phase.

Hope these thoughts help you get started...

-Kevin P.