stepper_motor_42bygh404

[alex_mikh]

hi there!

i have a stepping motor 42bygh404 (like here http://www.web-tronics.com/nema_17_stepper_motor_42bygh404.html) and i need to control it through LabView.
i'm gonna to use it for a neutral filter to control laser power in my setup.
I guess the motor can be connected through com port..
My knowledge about LabView are pretty weak, so i ask to describe possible solution or at least some ideas to start with in details!
regads, Alex 

[Blake-C]

alex_mikh,

That website didn’t seem to lead me to any helpful details about the motor. You’ll need some kind of controller for the motor and as far as what signals to send serially to the drive to communicate commands to the motor, that would all be drive-specific and may very well be proprietary to the company. Check out this forum post for more information on this. As far as doing this in LabVIEW, the way we interface with motors is by using a controller card (PCI, PXI, etc.) to communicate to the drive using our NI-Motion driver.

[alex_mikh]

Dear Blake-C!

thanks for feed back!

I figured out little bit about that motor. So, now I'm able to do manipulate it from LabView using basic commands : e.g.. make the motor executes  some numbers of steps and set up a delay between each step. To do it, i'm using ni usb-6009 and a stepping motor driver.

It works fine, but now i need to use it for my application, i.e. control neutral density filter wheel to choose laser beam power. I'm going to use for it some power meter, which also can be connected to pc. In principle, i need some sort of feed back loop between the filter (stepping motor)  and the power meter. I'm not sure what is the best way to organize it. As i said, I can rotate the motor only in one direction. Basically, now i'm wondering about how to bound the motor position and power values. I need some calibration, i.e. write a table or relation between those parameters.

maybe you have some experience with similar problems?

regards, Alex

[Blake-C]

alex_mikh,

Typically the controlling of motors is done through a motion controller. The NI USB-6009 is specifically designed for applications such as simple data logging, portable measurements, and academic lab experiments, but is not robust enough to provide control for a motor. Our motion controllers are specifically designed for interfacing with a motor drive to control a motor. These motion controllers also have built-in ports designed for feedback. At this point, you’re sending signals to the drive to translate and  send to the motor but you have no way of knowing if the motor is at the exact position that you’ve specified (i.e. moved the amount of step signals you’ve sent). In this case you’d need feedback but have no way to acquire that feedback. Our motion controllers also come with our NI-Motion driver that has motion-specific VIs to be used in programming motion control. Using the NI USB-6009 as a motion controller is highly unsupported if it is indeed possible. The driver also comes with examples that help walk you through how to set up different moves and applications with a motion system. The controller allows you to configure the motion system and set bounds. So if the NI USB-6009 is the trying to act as the motion controller, it may be impossible. If it is possible, it is going to take a significant amount of time and effort to make happen, all with no documentation or support on the process or potential issues you may face. I would recommend looking for one of our Motion Controllers to work with your application.