Magnetic encoders? Anybody else having trouble?

[Bryscus]

Sorry to be unclear in my last post. Yes, we were using the magnetic sensor in encoder mode. Were did seem to be getting good feedback. I didn't scope it, but we were getting count rates that seemed consistent and direction was also detectable.

All this was possible only at slow speed though. We could hit the Nyquist frequency for the cRIO input at very low speeds - maybe 15% or less of a CIM motor output, I can't remember the exact figure. At around this speed the encoder rate sign would change. We also would get very quantized numbers for speed (e.g., always something like dancing between 20142.464 and 21439.264 that were repeated exactly).

Just a thought, is it possible that having 4096 bit resolution that could correspond to 4096 ticks on an optical encoder and that the transitions actually happen 4x that speed? That would make matters even worse for sure.

So we gave up pretty quickly using the magnetic sensor and went to US Digitals instead. In hind sight I probably should have just rotated the shooter wheel one revolution and checked how many clicks it produced...