It isn't clear what your plans are for this "perfect" reference signal, but here are the two key reasons you're missing some positions in your data as you speed up your rotation:
1. You're task is in software-timed "on-demand" sampling mode rather than using a hardware clock and data buffer. Counter tasks can't derive their own sample clocks however, so you'll need to generate one elsewhere and "borrow" it. Typically, you'd configure your other counter to generate a continuous pulse train that you use as a sample clock.
2. While in software-timed mode, you've inserted a 10 msec delay in your reading loop. So you can only nominally read at <= 100 Hz.
300 RPM = 1800 degrees/sec. So the nominal movement between readings would be >= 18 degrees. Crank up the speed to 3000 RPM and that becomes 180 degrees.
- You need to do hardware-clocked sampling
- You may or may not actually need to sample at a rate that catches every 1 degree of motion. Think about your purpose carefully.
-Kevin P
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