Unsupported LabVIEW Features on NI Linux Real-Time Targets

Issue Details

What LabVIEW features are not supported on NI Linux Real-Time targets?

Solution

The next paragraph contains a detailed list of features that are not supported on Real-Time (RT) targets that run the NI Linux Real-Time operating system (RTOS). Examples for these targets are myRIO and recent CompactRIO. See the document Introduction to NI Linux Real-Time for a full list.
Refer to the specific RT target hardware documentation for information about what RT Operating System your target is running. The lists found on the page Real-Time Controllers and Real-Time Operating System Compatibility might also be helpful.

Unsupported Features

• ActiveX VIs
• NI TestStand VIs (ActiveX-based)
• .NET VIs
• Report Generation Toolkit VIs
• Windows Registry Access VIs
• Report Express VI (Uses the unsupported Report Generation Toolkit VIs)
• Graphics & Sound VIs
• Database Connectivity Toolkit
• G Web Server
• Menu functions
• Cursor VIs
• IrDA functions
• Call Library Function Nodes that access an operating system API other than NI Linux Real-Time
• Open/Create/Replace File function interactively using a file dialog box
• The Clear indicators when called option of the Execution Properties (VI Properties Dialog Box) page is not supported on RT targets
• The Auto Configure option of the Create Histogram Express VI is not available on RT targets
• RT targets support the Event Structure only with dynamic events, with the exception of cRIO-903X and cRIO-904X with the Embedded UI enabled that support UI Events as well.
• LabVIEW-built DLLs - NI Linux Real-Time supports only .SO libraries, which LabVIEW does not build
• Dynamically loading VIs without first compiling for LinxuRT platform - To dynamically call a VI on an NI Linux Real-Time target, you first must build a source distribution in the LabVIEW project. You can create a source distribution by right-clicking Build Specifications located under the NI Linux Real-Time target in the Project Explorer window and selecting New»Source Distribution from the shortcut menu. The source distribution must include the VI you want to call dynamically. Build the source distribution by right-clicking and selecting Build from the shortcut menu. Use WebDAV or FTP to transfer the built source distribution to the target and call the VI dynamically through the VI server
• LabVIEW Digital Filter Design Toolkit
• Certain Mathscript functions are not supported on RT targets*
• Certain Mathscript functions are not supported on RT targets only when you assign the output of the function to a MathScript variable*
• The Output Page of the LabVIEW MathScript Probe window is not supported on RT targets.* However, you can use the rt_debugoutput (MathScript RT Module Function)  to send debug strings to the standard output device.

*The LabVIEW MathScript Module is no longer offered by NI, and the LabVIEW MathScript Node is no longer included with LabVIEW 2023 Q3 and later.

Additional Information

When a VI or stand-alone application runs on an RT target, you cannot execute VIs that modify a front panel. For example, you cannot change or read the properties of front panel objects with property nodes because there is no front panel for VIs that run on the RT target. The VI still runs on the RT target but the front panel object is not affected and returns an error. In some cases, you can establish a front panel connection with the RT target to use some unsupported LabVIEW features. Right-click an RT target in the Project Explorer Window and select Connect from the shortcut menu to open a front panel connection with the target.

The following features only work on an RT target with a front panel connection:

• Front panel property nodes and control references
  Note - An RT target updates the values of property nodes and control references asynchronously, meaning a property node or control reference might not contain the latest value of the indicator or control
• Dialog VIs and functions
• VI Server front panel functions

Note - Some LabVIEW example VIs use unsupported VIs and functions and do not execute on an RT target

Debugging Reentrant VIs

LabVIEW debugging tools are not available for copies of reentrant VIs executing on RT targets. Because LabVIEW identifies copies of reentrant VIs by their front panels and VIs executing on RT targets do not include front panels, LabVIEW cannot open reentrant VI copies for debugging. However, you can run and debug your application on Windows prior to deploying the application to the RT target.