How Do I Generate a Chirp Signal in LabVIEW?

Updated Jul 18, 2019

Reported In


  • Multifunction I/O Device


  • LabVIEW
  • LabVIEW Sound and Vibration Toolkit

Issue Details

I want to output a chirp signal through my DAQ device in LabVIEW. Is there a way I can easily create a Chirp Signal in LabVIEW? Are there any considerations that need to be taken into account?


A chirp signal in which the frequency continuously increases (up-chirp) or decreases (down-chirp) with time as shown in the picture below. It is commonly used in sonar and radar applications, but has other applications such as stimulus response analysis and spread spectrum communications.

LabVIEW has a built-in function named Chirp Pattern VI that creates a continuous normalized sweep from a start frequency to a stop frequency, It can be found on the Block Diagram under the Functions Palette >> Signal Processing >> Signal Generation.

In order to output a chirp signal properly using a Data Acquisition device, you'll need to normalize the start and stop frequencies of the chirp signal to the sampling rate of your device by dividing the frequencies by the sampling. In this way, the Chirp Pattern VI will create a signal that when output at the sampling rate of your board, will be accurately represented in physical world.

Attached is an sample program that shows how to create a chirp signal that can be used for signal generation with National Instruments devices.

Alternatively, with the Signal and Vibration Measurement Suite there is a way to generate a chirp signal, also known as a sweep signal, for sine waves specifically with DAQ devices. Example code for the signal can be found under LabVIEW\examples\Sound and Vibration\Swept Sine directory.