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Managing I/O with Shared Variables (DSC Module)

LabVIEW 2013 Datalogging and Supervisory Control Module Help

Edition Date: June 2013

Part Number: 371618J-01

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You can use shared variables to represent a real-world input/output point. With the LabVIEW Datalogging and Supervisory Control (DSC) Module, you can configure how LabVIEW scales shared variable data, logs shared variable data to a historical database, and sets alarm levels and priorities for shared variable data. You also can bind shared variables to I/O servers, such as the OPC server, or to a shared variable published by another instance of LabVIEW on the network.

Note  You can use the features the DSC Module adds only for network-published shared variables.

You can configure a shared variable by editing shared variable properties. The shared variable properties that you can edit depends on the data type of the shared variable and on your target and licensed product(s).

Shared variables communicate between VIs, remote computers, and hardware through the Shared Variable Engine (SVE). The SVE is a data processing engine that manages the use and connectivity of shared variables. The SVE uses the NI Publish-Subscribe Protocol (NI-PSP) data transfer protocol to write and allow users to read live data.

The DSC Module also adds OPC functionality to LabVIEW, allowing shared variables to connect to OPC servers and clients. To connect shared variables to OPC server data items interactively, you can create an OPC Client I/O server, or use the Multiple Variable Editor window, available by right-clicking a project library or shared variable in the Project Explorer window and selecting Multiple Variable Editor from the shortcut menu. LabVIEW automatically publishes deployed shared variables to the OPC server.

Use the following topics to understand shared variables, the SVE, and shared variable properties.

Shared Variables

Shared Variable Engine

Shared Variable Properties

Related Information

Use the following links to find resources on the NI Developer Zone website for more information about the shared variables in LabVIEW.

To view related topics, click the Locate button, shown at left, in the toolbar at the top of this window. The LabVIEW Help highlights this topic in the Contents tab so you can navigate the related topics.

 

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