Hello.
Based on your post I am guessing that you are performing the control in software, i.e. starting a velocity move, and then reading the load cell until it reaches a threshold, then stopping the motion. As such you are essentially limited by the software control loop rates.
You are using PXI so it is possible that you are using real-time. If not, one solution could be to implement a real-time application that would be more deterministic, but again this would still depend on the software.
Depending on your system (stepper or servo), you could implement a direct analog feedback into the motion card itself, but this would require a signal which has a range much greater than your load cells. This is only a good option for servo axes. If this was somehow possible, you can tell the motion controller to move to a specified LOAD instead of a specified position/velocity. Provided you could appropriately condition the signal, this is the best choice.
Unfortunately, you cannot implement limit switches/etc over RTSI, so I believe that this will not be a good option.
A third, and probably most un-desireable option, is to output a voltage on the PXI-6025E proportional to the load received from the load cell. This voltage could then be used as the analog feedback for your motion device. This, however, still adds the software layer of delays.
I hope these ideas help you out.
Regards,
Colin C.
Applications Engineering
Colin Christofferson
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