You could have some logic to increment a pulse counter each time a pulse occurs, and some logic to determine when a second had elapsed and save the counter somewhere where you are holding 'current pulses per second', then reset the counter to zero.
You could have some logic to increment a pulse counter each time a pulse occurs, and some logic to determine when a second had elapsed and save the counter somewhere where you are holding 'current pulses per second', then reset the counter to zero.