Reading and Writing Shared Variables with the Variable Web Service

Using the variable Web service, you can create applications that access network-published shared variables through HTTP. Any shared variables that utilize the NI Publish-Subscribe Protocol (NI-PSP) can be accessed using the variable Web service. Using Open Data Protocol (OData), the variable Web service provides responses in both XML and JSON formats.

Note��The variable Web service does not support the following OData parameters: $filter, $select, $top, $skip, $links, $orderby, $inlinecount, and $batch.

Installing the Variable Web Service on a Real-Time Target

To use the variable Web service on an RT target, install Variable Web Service 12.0.0 on the RT target using the LabVIEW Real-Time Software Wizard in NI Measurement & Automation Explorer (MAX).

Granting New Permissions to Users

To use the variable Web service, you must grant the appropriate permissions to the appropriate users in NI Web-based Configuration & Monitoring. The following permissions are included with the variable Web service:

By default, these permissions are granted to the admin only. For information about granting permissions to users, launch NI Web-based Configuration & Monitoring and click Help on the Web Server Configuration page.

To identify themselves and utilize these permissions, users must log in to NI-Auth when prompted. Alternatively, the admin can disable authentication by granting all five permissions to the everyone group.

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