Connecting Hall Effect Sensor as an encoder(fe​edback) for PCI 7356 Motion Controller

Question

Hi,
We have Labview 2010 and the following hardwares for testing a specific motor (a brushless DC motor):
NI PCI 7356 Motion Controller
NI UMI 7774
AKD Servo Drive P00606
However, I met some difficulty when wiring the motor to the motor drive(and controller). In the manual, it says PCI 7356 needs encoder signals as the feedback. But our motor doesn't have a built-in encoder. It has three Hall Effect Sensors, which we plan to use as an encoder. If we feed the hall sensor signals as the encoder phase signals (Phase A, B) to the drive/controller, I wonder if Labview or PCI 7356 (after an appropriate configuration) can adjuct the phase (from 120 degree to 90). Does it work even without the adjustment?
If the above doesn't work, can I feed only one Hall Effect sensor signal as Encoder Phase A and don't feed anything to Phase B (since I only need control the motor speed in one direction)? Will PCI 7356 or Labview recognize the signal and function accordingly?
If it doesn't work as well, could I use motor's Back EMF as a feedback (this motor produces a decent sinusoidal back EMF)? If I can, how should I configure the hardware and wire the motor to controller accordingly? 
If all three above don't work, could you suggest a way to solve this problem?
Thanks so much for your help.
Best,
Chen

Answer 1

Hey Chen,
I have comfirmed that the PCI card will not be able to do feedback with the hall effect sensors. However, you could do that with our NI 951x modules if you run it in FPGA mode. You would need an extra IO module to set up the hall effect sensors with, but you could effectively customize your control and your feedback on the FPGA board immediately. 
For your other post, I am not sure you can create a time constraint on the move, I believe that when you define a motion, you would need to define the number of steps or the position and not the time. If you are running the motor at a specific velocity for an amount of time, you would need to set that as the number of revolutions and not time.
I hope this helps.
Regards,
A. Zaatari
National Instruments
Applications Engineer