And if you want rate within a couple of cycles, then just calculate rate at every cycle completion, and average the last few if you find the need. Just divide the last cycle time into the time per period, in your case minutes or 60000 milliseconds. Within two or three cycles, you will know the rate at which the machine is producing. This is very useful when manually adjusting speed of anything affecting the cycle rate for quicker feedback. It can also make scheduling and projection math more accurate.