LabVIEW is a useful instrumentation and analysis software developed by National Instruments. It stands for Laboratory Virtual Instrument Engineering Workbench [2].

• It's a visual graphical (G) programming language.
• It has libraries of functions and development tools for data acquisition and instrument control.
• It's designed for real time analysis.
• It uses icons to represent fucntions.
• Its programs are called Virtual Instruments, or VI for short.

VIs are combination of a Front Panel and Block Diagram (see Figure 2 above). LabVIEW VIs can used within other Vis as sub-Vis because they are hierarchical and modular.  In other words, one can use them as top-level programs, or as subprograms within other programs (see Figure 3).