Managing I/O with Shared Variables
- Updated2025-11-07
- 2 minute(s) read
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 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.
Related Information
- Supported Shared Variable Properties Based on Data Type
- Supported Shared Variable Properties Based on Target and Products
- Creating OPC Client I/O Servers
- Create Shared Variables
- Deploying, Committing, and Monitoring Shared Variables
- Pass Data between LabVIEW and the Shared Variable Engine
- Edit Shared Variable Properties
- Configure Shared Variables