Here's an example program:
This VI simulates the functionality of a Radio Shack Analog Sound Pressure Level (SPL) Meter. This VI requires a data acquisition board, Radio Shack SPL Meter and an RCA cable. Connect one end of the RCA cable to the SPL Meter's output, and then splice off the other end and connect it to channel 0 of the DAQ board. The connection to the DAQ board must be made differentially.
The output of the SPL meter is a raw waveform that is converted by the program into a decibel (dB) reading. The front panel shows a dB offset based on a range, just like the actual SPL meter. The front panel also displays the overall dB reading.