Structures
Owning Palette: FPGA Module VIs and Functions
Installed With: FPGA Module. This topic might not match its corresponding palette in LabVIEW depending on your operating system, licensed product(s), and target.
Use the structures to control data flow.
If you use a global variable in an FPGA VI, the global variable maps directly to a register on the FPGA target. Use global variables to transfer data between loops efficiently.
 | Note This palette is specific to FPGA targets and contains a subset of the VIs and functions that are on this palette when you edit a Windows or RT target VI. |
Refer to the Structures Palette Details topic for information about Timed Loop compatibility, usage, timing, and resource considerations related to the objects on this palette.
| Palette Object | Description |
|---|---|
| Case Structure | Has one or more subdiagrams, or cases, exactly one of which executes when the structure executes. The value wired to the selector terminal determines which case to execute and can be Boolean, string, integer, or enumerated type. Right-click the structure border to add or delete cases. Use the Labeling tool to enter value(s) in the case selector label and configure the value(s) handled by each case. |
| Conditional Disable Structure | Has one or more subdiagrams, exactly one of which LabVIEW uses for the duration of execution, depending on the configuration of the conditions of the subdiagram. Use this structure when you want to disable specific sections of code on the block diagram based on some user-defined condition. Right-click the structure border to add or delete a subdiagram. |
| Diagram Disable Structure | Has one or more subdiagrams, or cases, of which only the Enabled subdiagram executes. Use the Diagram Disable structure to disable a section of the block diagram. |
| Feedback Node | Stores a data value from one execution of a VI or loop to the next. A Feedback Node is analogous to a z^-1 block in feedback control theory and digital signal processing. |
| Flat Sequence Structure | Consists of one or more subdiagrams, or frames, that execute sequentially. Use the Flat Sequence structure to ensure that a subdiagram executes before or after another subdiagram. |
| For Loop | Executes its subdiagram n times, where n is the value wired to the count (N) terminal. The iteration (i) terminal provides the current loop iteration count, which ranges from 0 to n-1. |
| Global Variable | Use global variables to access and pass data among several VIs. |
| Local Variable | Use local variables to read or write to one of the controls or indicators on the front panel of a VI. |
| Stacked Sequence Structure | Consists of one or more subdiagrams, or frames, that execute sequentially. Right-click the structure border to add and delete frames or to create sequence locals to pass data between frames. Use the Stacked Sequence structure to ensure a subdiagram executes before or after another subdiagram. |
| While Loop | Repeats the subdiagram inside it until the conditional terminal, an input terminal, receives a particular Boolean value. The Boolean value depends on the continuation behavior of the While Loop. Right-click the conditional terminal and select Stop if True or Continue if True from the shortcut menu. You also can wire an error cluster to the conditional terminal, right-click the terminal, and select Stop on Error or Continue while Error from the shortcut menu. The While Loop always executes at least once. |
| Subpalette | Description |
|---|---|
| Decorations | Use the decorations located on the Decorations palette to group or separate objects on a block diagram with boxes, lines, or arrows. These objects are for decoration only and do not modify data. |
| Timed Structures | Use the Timed Loop structure to control the rate at which a subdiagram executes. |