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Overview
This VI correlates frequency measurement with the time base of an analog input measurement in software.
Description
One applied case is the correlation of power data with temperature and pressure acquisitions in the 5-40 Hz range. The actual timing will slightly differ due to the two signal types. This VI is best suited for low frequency measurements.
Requirements
Steps to Implement or Execute Code
Additional Information or References
VI Snippet
**This document has been updated to meet the current required format for the NI Code Exchange.**
Example code from the Example Code Exchange in the NI Community is licensed with the MIT license.
Hello
how is the connection on the DAQ signal. since you are using both inputs (ai and counter) from where you get the waveform?
thanks for the post
Thanks for the message yahya2006,
If I interpret your question right, the waveform data from the counter is built within the while loop using the time information from the AI. This is not effective for higher speed measurements since the measurements actually use different timing sources, as mentioned in the comments above. Please post a reply if this does not answer your question.
Thanks,
Chris
Hello Chris and thanks for your reply.
Actually i was testing your vi on my DAQ signal Accessory. However I was not sure if i connect the AI channel directly to the counter input since both are inputs for signal.
On the DAQ i have a generator function and i want to measure the frequency of the signal by using the counter.
Thanks
Yahya2006,
If order to make a frequency measurement on the signal generated by the frequency generator (square wave) you can create a frequency measurement task referencing the counter input. Find more information on this task type below. Alternatively, you can make a frequency measurement on an analog input signal in software by using an FFT or other frequency analysis VIs.
Frequency Measurements: How-To Guide - Developer Zone
http://zone.ni.com/devzone/cda/tut/p/id/7111
Best,
Chris