Load/Displacement test set-up help

[Jeremy Robots]

I'm have a difficult time choosing a set-up for a new test. I was hoping for a little help. I need a test that will utilize a load cell and a stepper motor that will take the load cell to a pre-load condition (.1kg), then zero out the position. Next, the load cell must be taken to a known load (X), and the diplacement needed to obtain that load value needs to recorded (deflection). Then the load must be taken to known load (2X), then back to pre-load condition, and change in position at pre-load will be recorded (deformation).

Motor and controller are from ZABER. Motor is a NEMA Size 23, 60mm travel (model #NA23C60), 175 lb force; controller is a 2 phase, up to 2.5A per phase stepper motor controller (model #T-MCA). Motor connects to the controller with a Minidin 8. Data cable on controller is a controller is a Minidin 6 connector.

I am not sure what the best set-up would be. My initial set-up was completely wrong. I was told to use a cRIO, but am not sure what that is.  Any suggestions?

Message Edited by Jeremy Robots on 01-06-2010 12:22 PM

[The_Chancenator]

Hi Jeremy,

NI has two options for motion- a PC/PXI based system, or a real-time based system.  The second option here is where the cRIO comes from. You can purchase motion controllers to insert into this chassis, then run the motion system from here (independent of a computer).  The first option requires either a PC or PXI system, with a PCI card as your controller.  

I'm guessing that the controller from ZABER is a PCI card.  How are you planning on communicating with it?  LabVIEW communicates with National Instruments' controllers via the NI-Motion driver; however this won't work for third party cards. 

So, are you looking for a way to get this motion system set up using new hardware, or your existing hardware?  If you are planning on using your existing hardware, does ZABER provide any drivers for LabVIEW?

Regards, 

[Jeremy Robots]

Marti C-

Thank you for the reply. Given the choice, I would prefer to use option 1 and run the test from a dedicated laptop. I don't have any hardware for this set-up yet. I basically started with the motor because it meets or my requirements. I chose the Zaber controller because I thought it would be the easiest way to control the motor. This is all pretty foreign to me, so I'm open to anything really.

Zaber does make drivers for Labview (http://www.zaber.com/wiki/Software/Labview_Driver), however the T-MCA controller is new and is not listed as a tested product. I'll contact Zaber and confirm whether or not it will work. Initially, I had chosen a chasis with an AI and AO card, but was told that it wasn't going to work. Kind of at my wits end.

Thanks

Jeremy Robots

[Don_Kirkby]

Hi, I wrote the LabView instrument driver for Zaber Technologies, and it works fine with the T-MCA. It comes with several example VIs, including some that show you how to loop through a series of movements. I suggest you play with the examples, and then adjust them to match your requirements.

It sounds like you could request a series of small moves and read the load after each move. When the load hits one of your target levels, change the movement direction and continue making small move requests until you get to your final target.