Unsupported LabVIEW Features (Real-Time Module on VxWorks Targets)

The following features are not supported on RT targets that run the VxWorks real-time operating system (RTOS). Refer to the specific RT target hardware documentation for information about the RTOS installed on the target.

• 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 VxWorks
• Open/Create/Replace File function interactively using a file dialog box
• The Clear indicators when called option of the Execution Properties page is not supported on RT targets.
• The Auto Configure option of the Create Histogram Express VI is not available on RT targets.
• File and folder access restrictions are not enforced on RT targets.
• Event structures on RT targets do not support events associated with user interface objects, such as VI panels or controls. For example, associating the Value Change event with a control does not work. RT targets support only user events.
• LabVIEW-built DLLs—VxWorks supports only .OUT libraries, which LabVIEW does not build.
• Dynamically loading VIs without first compiling for PowerPC platform—To dynamically call a VI on a VxWorks RT 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 VxWorks 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. You then can FTP 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 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 function to send debug strings to the standard output device.
• Certain Advanced TDMS functions are not supported on RT targets.

Modifying Front Panel Objects of RT Target VIs

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.

Real-Time Module and Express VI Considerations

LabVIEW Express VIs increase LabVIEW ease of use and improve productivity with interactive dialog boxes that minimize programming for measurement applications. Express VIs require additional performance overhead during execution; therefore, do not use Express VIs in deterministic or processor-intensive applications. Instead, develop real-time applications with standard LabVIEW VIs.

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.