LabVIEW Encoder not reliably returning Rate

[cabbagekid2]

We just got started with the encoders that came in the KOP and are running into the same issue as everyone else. Our right side has both rate and distance but the left side only shows distance (rate is 0).

Originally Posted by lon.bushweiler

We ran into similar issues in Labview over the weekend. Like others, we wrote our own rate code and moved on.

We're going to write our own rate code and was wondering...since distance works for both sides if it's as simple as storing the present distance into a variable and subtracting the saved (previous present distance) from the prsent distance. This will be in periodic task...so that you can divide it by the loop time interval to obtain rate.

We tried this for our working side and came up with similar results as the encoder rate output and are hoping to get it working on the left side.

One thing we noticed though (both with our rate and the VI rate) is that it's REALLY noisy. When maxing out the joystick it bounces around anywhere from zero to 250 rpm (low gear). We had to up the sample average (which cleaned it up a little) and then added a point by point median filter. The only thing bad about this is that the filtered rate is only 100 rpm (can you imagine the noise to produce this!).

Anyone else have noise issues? We're still not sure if the rate data will be workable after all this filtering. More testing today...

Might also be the placement of our wires...will test that today too.