[Hugh Meyer]

fovea1959,

Using the 100 line encoder with one channel rather than quad mode will reduce the pulses per second considerably.

If you are seeing noise you might want to check your mechanical arrangement. The signals we see are rock solid when all is properly aligned and constrained.

If you have something spinning that you could drill a hole in you could use a LED and photo transistor to sense the hole. A slot sensor is another option (HOA1405)

If you could mount a black and white sticker on the spinning shaft then a reflective sensor (OPB625) would work great.

Either of these devices can connect directly to the cRIO with only a few resistors.

Good luck. Please be sure to post your final solution. It is always interesting to see how others solve problems like this.

-Hugh