Attempt to operate stepper motor

[antfahed]

I am using a PCI-6024e DAQ with a BNC-2120 board and was inquiring on the capability of operating a stepper motor on a radio telescope using this hardware and the LabVIEW software as part of an undergraduate indepedent research project for Randolph-Macon College in Ashland, VA.  To operate the motors, a 40V and 4A pulse must be used.  To operate these motors by computer, how could this hardware be used to output a signal of this magnitude to operate the motors?

[AnalogKid2DigitalMan]

Cool project!

You cannot directly drive a stepper motor from the DAQ card. You need a piece of hardware called a stepper motor driver. You can send step pulses out of the counter/timer output on your DAQ card along with a digital output to control direction that are wired to the stepper motor driver. The driver then decodes these signals and drives the motor phases with the 40V 4 A pulses (powered by a suitable power supply) to create motion. The manufacturer of you stepper motor may be able to provide you information regarding an appropriate driver to use.

There are several white papers and tutorials on Nationals site that discuss stepper motors. Plus you can search teh Discussion Forums for 'stepper' and you will probably find a great deal of additional 'hands on' information and code.

[antfahed]

Thank you for your input.  We currently have two motors that control the telescope that are controlled by two manual drives.  I was wondering if you would know if it would be simpler to just configure the computer to take the place of the person pushing the buttons on these manual drives, somehow configuring the computer to send a signal to these drives which would in turn cause the motors to move. (Sort of like the computer pushing the buttons instead of the person)  The buttons currently are pressed and held down, causing the telescope to move and enabling pointing of the dish.  Would this be easier or would it be simpler to find the motor drive you were speaking of and using the DAQ along with the stepper motor drive?

[AnalogKid2DigitalMan]

That would be easier to do. The DAQ card could be used to turn on relays (electrically controlled switches) that can be wired up in leiu of the existing manually operated pushbuttons.