Wrap It Up

Wrap It Up!

The LabVIEW environment has three main parts: the front panel, block diagram, and the icon/connector. The front panel is the user interface of the programyou can input data through controls and observe output data through indicators. When you place an object on the front panel using the Controls palette, a corresponding terminal appears in the block diagram, making the front panel data available for use by the program. Wires carry data between nodes, which are LabVIEW program execution elements. A node will execute only when all input data is available to it, a principle called dataflow.

A VI should also have an icon and a connector. When you use a VI as a subVI, its icon represents it in the block diagram of the VI you use it in. Its connector, usually hidden under the icon, defines the input and output parameters of the subVI.

LabVIEW has two types of menus: pull-down and pop-up. Pull-down menus are located in the usual menu spot at the top of your window or screen, while pop-up menus can be accessed by "popping up" on an object. To pop up, right-mouse click on Windows and Linux machines and <command>-click on the Mac, or click with the Pop-up tool. Pull-down menus tend to have more universal commands, while pop-up menu commands affect only the object you pop up on. Remember, when in doubt about how to do something, pop up to see its menu options!

The Tools palette gives you access to the special operating modes of the mouse cursor. You use these tools to perform specific editing and operation functions, similar to how you would use them in a standard paint program. You will find front panel control and indicator graphics located in the Controls palette, and block diagram constants, functions, and structures in the Functions palette. These palettes often have objects nestled several layers down in subpalettes, so make sure you don't give up your search for an object too soon.

The Help window provides priceless information about functions and how to wire them up; you can access it from the Help menu. LabVIEW also contains extensive online help that you can call up from the Help menu or by pressing the online help button in the Help window. Between these two features, your questions should never go unanswered!

You can easily turn any VI into a subVI by creating its icon and connector and placing it in the block diagram of another VI. Completely stand-alone and modular, subVIs offer many advantages: they facilitate debugging, allow many VIs to call the same function without duplicating code, and offer an alternative to huge messy diagrams.

Don't worry if this seems like a lot to remember. It will all become natural to you as you work your way through the book.