Could you please give a little more information about your application. What hardware are you using? The output of a piezo transducer will not look much like a waveform. The output will be a dc voltage that is somewhat proportional to the force applied to it. There will be one main peak, then lots of ringing after that. That would technically then become an ugly ac waveform. I have used the NI 5102 digitizer to view outputs like this.
An accelerometer module, if I'm thinking of the same thing, will condition that signal. It will usually isolate and amplify the signal so that conventional instruments can read the signal easily.
How Labview comes into play here depends on your hardware.
