Position-based explicit force control with cRIO

[kyleshook]

Hello,

I want to use a linear stage to apply a force on a sample with load cell feedback. I am using a cRIO-9074, NI 9516 servo drive and an NI 9201 for the load cell feedback. 

I have the following questions:

1) Can anyone point me to examples of a position-based force controller in LV using a 9516?

2) Is it possible to achieve this with SoftMotion Standard or do I need SoftMotion Premium? Can I do this without SoftMotion (what else would I use?)

Thanks for your help,

Kyle

[Emily-C]

Hi Kyle,

There aren't any examples that use a load cell for feedback. You would need to implement an application that will adjust its position based on the force you read back from your load cell. 

It is possible to do this without SoftMotion, but it requires FPGA programming, which is much more complicated than using SoftMotion for your motors. You can find an example for FPGA programming on the 9516 in the LabVIEW shipping examples under Toolkits and Modules > FPGA > CompactRIO > Module Specific IO > Motion Control > NI 9516 Basic Move.

If you'd like to use SoftMotion to control your 9516, there is a SoftMotion example under Toolkits and Modules > NI SoftMotion > Device Specific > NI 951x > Servo Interface (9516).

You could modify these examples to react to the force read by your load cell.

I don't know all of the specifics of your application, but from what I understand SoftMotion Standard should be sufficient. These documents provide some more details on the difference between Standard and Premium:

http://digital.ni.com/public.nsf/allkb/74BDDA70348AE2798625785E006EB200

http://www.ni.com/white-paper/9414/en

I hope this helps!