Three Axis Stepper motor control and DAQ

[irishmick]

Hi everyone I was hoping someone could help me with my problem  as follows

I need to develop an application that will control a 3 axis stepper motor probe traverse mechanism whilst simultaneously acquiring an analogue signal from a sensor at each step. The traverse mechanism will move in a square grid in y and z whilst acquiring an analogue signal at each step. I have downloaded Labview 2010 and also the NI DAQ mx driver software. Could anyone please shed some light on this topic and also maybe the best equipment or best way to go about doing this. I dont have any experience of Labview or electronics before. I have gone through some basic tutorials on DAQ with analogue signals but im clueless as how to incorporate the DAQ with the control of the three stepper motors. This is a vital part of my PHD studies and I would be extremely grateful for someones help on this subject.

Thanks in advance

Mike 

[nathand]

You'll need a stepper motor controller, preferably one that can do three axes (three 1-axis controllers will work too).  What make and model are your stepper motors?  NI sells motion control hardware, as do many other companies.  Copley Controls provides good LabVIEW examples; I've also used controllers from Parker but they require more work in LabVIEW.

You'll also need an analog input card, if you do not already have one.  What sort of analog signal are you measuring (0-5V, -10 - +10V, 0-20mA, something else)?  What level of resolution do you need?  How fast do you need to sample?  This information, and your budget, will help you determine the right card.  Your local NI representative can help with this.

Once you have your hardware then you can start learning how to work with and control it.

[scottcolston]

whats your budget?

NI motion controllers/drivers can be expensive. Cheaper ones can be purchased - some will have analogue/digital inputs.

I've sampled on a step before. you can use the step signal from a controller (before the power/drive stage) and use this as the sample clock (PFI) on most NI DAQ devices.

[irishmick]

Hi Nathand, thanks for your reply, basically what is running on the Traverse at the moment are3 Astrosyn stepper motors driven by 3 one axes Astrosyn P402 motor controllers and the traverse is being positioned using Mach 3 CNC software. What I want to do is to combine the control of the traverse and also the DAQ and data processing into one package in Labview. Is it possible to control these type of motor drivers with Labview? My analogue voltage to be sampled is between 0-5V and my sampling rate is about every1-2secs I would need to acquire a voltage signal from 5 pressure trandsucers. I was thinking maybe of the NI USb 6008/6009 as it is pretty cost effective for my current budget. Any more help would be greatly appreciated.

Thanks

Mike

[irishmick]

Hi Scott, thanks for your reply also. My budget is preferably around 1000-1500 euro for completion of the program and DAQ unit so I can then run my experimental analysis. Can u give me a more detailed explanation of how to acquire the signal on each step? What would I need in terms of hardware to send a signal to the motor controllers in order to control their motion in x, y and z? Your help is greatly appreciated.

Thanks

Mike

[nathand]

For that sample rate the USB 6008 or 6009 is fine.

As for the motor control, I think there's one piece missing from your description.  It looks like the P402 is a stepper drive/amplifier, not a controller.  It gets step and direction signals from somewhere.  What is providing those signals in your system?  That's the piece that LabVIEW will need to talk to, unless the CNC software provides some sort of hook for external software such as an ActiveX server (unlikely, and you'd need to check the documentation to find out).

[S.Limb]

Hi Mike

I hope that your PHD project is going to plan at the moment. As I understand it, your project is to incorporate 3 controller channels and 5 pressure data input channels within one easily managable system. I have found some literature on getting started with NI motion control which I think you will find a useful resource.

I have looked into some products for you as well and a number of our motion controllers have analog input channels, but they are nearer the top end of your budget. The link provided shows you an example product which has the requirements you need.

When you have decided on your equipment there are a number of examples provided with LabVIEW on DAQ, triggering and motion control, which will give you an idea on architechture ideas for your code. Triggering your acquisition at each step is probably a good way to acquire the analog data at specified times.

If there is any thing else I can help you with regarding the setup of your system please dont hesitate to ask and if you are still struggling with the products please feel free to phone your local branch where someone will be able to talk you through some products and services to fit with your application.

I hope this is helpful

Thanks