Square wave frequency, daq

[Yanukas]

Hi,

I'm using DAQ mc 1208LS to get square wave(tachometer signal from pump), and for few days I'm trying to some how measure frequency. 

Using examples I was able to connect and get strip charts, but I have no idea how to measure(count?) frequency.

Also my knowledge of LabView is extremely low...

Thanks in advance for help

J

[aeastet]

What have you tried so far? Did you look at the basics training that Ni provides? There are also examples for this exact thing if you look at the examples that ship with LabVIEW.

[arteitle]

That DAQ module may have frequency measurement built in; when you're creating the measurement channel, will it let you create a frequency input instead of just a digital input? If not, there are two ways to measure the frequency of a pulse: 1. count the number of pulses that occur within a known period of time and then divide the former by the latter, or 2. measure the time interval between two pulses and take its reciprocal. They each have their pros and cons; are you more interested in quick response to changes in frequency, or stability and noise immunity?

[Yanukas]

Thanks for fast reply! I combine solution from both of you:)

My DAQ has counter input so I connected tacho to it, then I checked examples and found something similar, then I read some basic tutorial, modify example and it's working. Thanks again!