A shared variable is a memory space that you can read data from and write data to. You can read and write shared variables on a single computer with single-process shared variables or on multiple computers with network-published shared variables, which publish data over a network using the NI Publish-Subscribe Protocol (NI-PSP). Use shared variables to publish only the latest values in a data set to one or more computers.
|Note To transfer every data point from one computer to another, National Instruments recommends sending commands or streaming data continuously with network streams. Refer to the Transferring Data over a Network topic for more information about choosing a networking feature that best fits your application needs.|
In general, you must complete the following tasks to publish latest values with a shared variable:
The LabVIEW Real-Time and DSC Modules offer additional configuration and programming options for shared variables. For example, you can enable the real-time FIFOs of shared variables with the Real-Time Module and configure scaling and alarming properties for shared variables with the DSC Module. Refer to the Real-Time Module and DSC Module Help for more information about extending the functionality of shared variables.
This book mainly describes the process of publishing latest values over a network using network-published shared variables. However, you also can perform the following tasks with other types of variables: