[Kevin Sevcik]

If you're trying to use this value for closed loop control, then yes you probably want to use the period value instead, and update your value quicker. You'll also get vastly more useful data out of the period with much higher resolution. Counts only come in integer values, so the smallest change in RPM you can detect is 60 RPM. The period is going to be measured in rather smaller increments, so you should get much higher resolution data out of it. Also, you might be able to use the period measurement straight in your teleop loop instead, as long as the function block returns a good value even if it doesn't have a new period value yet.