Microsoft Word me104 lab1 2003. doc

5
• Wires are data paths between nodes.
• Terminals are ports through which data enter and exit. Input data from the controls on the front panel pass through the control terminals to the block diagram. Data generated by the block diagram pass through the indicator terminals to the front panel to be displayed by the indicators. Nodes may also have terminals to receive and send data. Think of terminals as entry and exit ports. Tracing the dataflow through the mult & div VI in Figure 1, you see that data entered into the controls (a and b in Figure a) exit the front panel through the control terminals (in Figure b) to the block diagram. The data then flow along the wires and enter the terminals of the Multiply and Divide functions. When the Multiply and Divide functions complete their internal calculations, they produce new data values at their exit terminals. These values flow to the indicator terminals and reenters the front panel, where they are displayed by the indicators. The terminals, nodes, and wires makeup the graphical programming language G. Nodes are analogous to statements, operators, functions, and subroutines. Terminals are analogous to variable and constant parameters in text-based programming languages, such as Cor FORTRAN. Thus, the block diagram is the graphical source code which controls the dataflow and execution of your VI.

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