acquire resistance value using usb 6501

[mak49]

I want measure a variable resistance value continuously for a LabVIEW program, what kind of daq card i want to use, and also i want control a stepper motor using same daq card

[crossrulz]

How quickly do you need to control that stepper motor?  How fast do you want to measure your resistance?  What is the range of the resistance you are going to measure?

[Buechsenschuetz]

It is not possible to control a stepper motor directly with a DAQ interface. You wil need some additional hardware such as a stepper motor driver and a power supply for the latter. 

Once you selected a stepper motor driver unit, the control possibilities depend on the interface between the stepper motor driver and the control system. Some will need pulses for each step and a logic level for direction control (and with these you have to write your own accelaration and deceleration. Others use an advanced data protocol and you just have to transfer parameters for motion control. 

[mak49]

I need to rotate(sweep like a pendulum movement) a stepper motor between 0-9 degree, i have ni daq 6501 and ni softmotion software. Now what i have to do please help me

[mak49]

And what type of driver circuit i have to use?

[Buechsenschuetz]

since you are obviously a newbie concerning stepper motors, reading some introductional papers might be helpful for you. 

http://www.ni.com/white-paper/4167/en/