LabVIEW 2018 Help
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Requires: Base Development System (Windows)
Right-click a project library or folder within a library and select New»Variable from the shortcut menu, or right-click an existing shared variable and select Properties from the shortcut menu to display the Shared Variable Properties dialog box and this page.
Use this page to set the basic network options for a shared variable. You also can use the Variable Reference property with the Variable properties to configure shared variables programmatically.
This page includes the following components:
- Use Buffering—Enables you to store data from the variable in a first-in-first-out (FIFO) buffer. The shared variable overwrites the first value in the FIFO if the FIFO reaches capacity. You can use buffering only for network-published shared variables.
- Number of arrays—Specifies the number of arrays of elements the buffer can contain. This control appears only for array data types.
- Number of elements (type: xxx)—Specifies the number of shared variables the buffer can contain. The data type you select in the Data Type pull-down menu determines the variable xxx. For array data types, this control specifies the number of elements within each array that the buffer can contain. This control does not appear for all data types.
- Single Writer—Sets the shared variable to accept changes in value from only one target at a time. This component is available only for network-published shared variables.
Selecting this option ensures that the shared variable write operation is not affected by another instance of LabVIEW.exe. The Shared Variable Engine restricts writing to a single VI on a single computer. The first instance of LabVIEW that connects to the shared variable can write values, and any subsequent instances cannot. When the first instance disconnects, the next instance in the queue can write values to the shared variable. LabVIEW notifies writers that are not allowed to write to the shared variable.
|Note You can create, configure, and host shared variables only on Windows or RT targets with the LabVIEW Real-Time Module. You can use the DataSocket VI and functions to read or write shared variables from other platforms.|