Measure time between pulses coming from a speed sensor

[Leahcim]

I am a very new user to LabVIEW. I am working on a senior project that requires precise speed measurements for a motor shaft. We have assembled an infrared speed sensor which returns a pulse (I believe 5V) to a channel in my DAQ system. I am able to see the pulse, and how it changes with speed. However, I am not sure how to measure the pulse frequency, so I may calculate a rotational speed.

Thanks

[EdDickens]

What type of DAQ card are you using?

If it has a counter on it, you should be using that instead of an analog input channel. Counters can provide very precise timing information from digital signals. They can give you a simple pulse count, frequency, period, pulse width, position for encoders and edge separation. You'll get much better timing a lot easier.

Have a look through the examples that ship with LabVIEW. There are some good ones that show the basic use of counters.

Try that and see if it gets you going in the right direction. If you need more information, post here agin.

Ed