How to measure the period of each consecutive pulse in a pulse train?

Question

Hello all,
   I am trying to measure every pulse period in a infinite pulse train. the pulse is actually from a encoder(360 pulse per rev) connected to a varing speed shaft. The mean speed is around 6000 rpm at the highest point, and it has periodic variation, this is why I want to measure the instantaneous speed.
   I tried to use A signal of encoder (360 pulse per rev) to connect to CI Period measurement terminal and read 360 sample at a time. but it seems more than half of pulse reading are missing, which looks like that the read vi need some time to finish the measurement of every pulse before it can handle next one, cause it miss some pulse.  The A signal I injected is around 10 KHz. Does my PCI-MIO-16E-4 or DAQ 6036 capable to handle this task?
thanks
Feilong

Answer 1

Hi Conseils,
   Thanks for your reply. I took a look on that discussion thread and started to study the "continously semi period buffered measurement.vi". I set a signal generator which gives 7 pulses once you press its trigger button to verify if that code could pick up all the resault. The frequency is set to 3KHZ.
  I also modified that vi a little bit to explicitly set DMA transfer and changed it to finite sample mode with 6 samples at a vi run.
  The min T value I input was 0.000028 s and max is 0.00042 s, which gives a engine rpm range of 400 rpm to 6000 rpm at 360 pulse per rev.
  And I input 4 into "sample to read" control.
  When I run the vi, after have signal generator output pulses, there's error:
 Error -200278 occurred at DAQmx Read (Counter 1D DBL 1Chan NSamp).vi:1
 Possible reason(s):
Attempted to read a sample beyond the final sample acquired. The acquisition has stopped, therefore the sample specified by the combination of position and offset will never be available.
Specify a position and offset which selects a sample up to, but not beyond, the final sample acquired. The final sample acquired can be determined by querying the total samples acquired after an acquisition has stopped.
Attempted to Read Sample: 6
Property: RelativeTo Corresponding Value: Current Read Position
Property: Offset Corresponding Value:
    It looks like the sampling procedure stops before the read.vi get enough (was 4 in this case) sample. But the sample I injected was 7 in total and the finite sample property was set to 6, which should satisfy the property of number of sample to read in read.vi.
    Could you please tell me where I am going wrong?
Many Thanks
Feilong