chen56,
Without knowing which hardware you are using or knowing the magnitude and duration of your peaks, I cannot confirm if your Data Acquisition device will consistently detect the peaks or trigger off an analog signal. Assuming that your DAQ device does support the needed features and has both the resolution and speed to adequately capture your peaks, then this project can be broken down into two parts.
First we will need to bring your data into LabVIEW. I would start with the DAQmx shipping example
Cont Acq & Graph Voltage - Int Clk-Analog Start.vi. This program takes data from ai0 when it sees an rising analog level on APFI0. These levels are adjustable to detect voltages of different thresholds.
Secondly, we will need to process the data to detect the peaks. There is a very good example program that shipped with LabVIEW called
Peak Detection and Display.vi. This example is basically built around the vi
Peak Detector.vi.Take a look at these examples and see if they fit your needs. If you have any further concerns please let us know what hardware you are using and please describe to us size and duration of the voltage peaks. Thanks and good luck!
Best Regards,
Jeff Tipps
Applications Engineer
National Instruments
