measure frequency of digital random signal

Dear all.

I want to measure the frequency of the signal. This value will be sent to other device to vibrate the vibrator according to the value.

For example, I want to measure this signal:

I have try using tone measurement vi and extract single tone measurement vi, but the result is not right, for example, if I have no pulse on the graph the result is 11,5hz  (it must be 0 hz)

I use NI USB 6210 and DAQ assistant to get data from sensor