capturing one cycle or revolution of a target wheel

[scientist]

I am acquiring waveform data from a test stand, a spinning target wheel. I need to save the data from one revolution/cycle only. Does anyone have any suggestion?

[Dave_Kaufman]

If you are controlling the wheel via LV DAQ, you should be able to translate the AO voltage to a RPM value. Then, based on this RPM value, take data for a time period equal to one revolution.

If you don't know the translation from V to RPM or are not controlling the wheel through LV, you may need to find the relationship. Make a target wheel with one small target. Vary the voltage to the motor and take waveform data. From this data, you can come up with the equation to convert V to RPM.

Hope this helps.
Dave.

[scientist]

Thanks for that part, but how do I know on which tooth of the target I am starting?

[Dave_Kaufman]

Can you turn the target wheel motor on and then physically restrain it from turning (e.g with your finger) without damaging the motor? If so, start the motor, hold the target at a known position, start data logging, then release the target. This should give you a profile of the target. It won't be exact, due to the initial acceleration of the motor, but you should see a cyclical pattern that you could then match up to the data you take.

Dave.