Real-Time Module on VxWorks Targets

Special Considerations

Keep the following considerations in mind when using a VxWorks target:


  • The RTOS does not support virtual memory or memory protection. If one task crashes, the target restarts to avoid unpredictable effects on other tasks.
  • Time zone changes require a target restart.

File System and Directory Structure

  • The file system is not case-sensitive.
  • Directory paths display in Windows format. For example, paths use backslashes and contain drive letters. If you open a VI created for NI Linux Real-Time targets in a VxWorks target context, the Linux-like paths automatically convert to Windows-like paths.

Web Services

  • The FTP server is enabled by default.
  • The WebDAV server is as an optional installation for your target.
    Note  The WebDAV server is not available in safe mode.
  • SSL is disabled by default.
  • NI Web-based Configuration & Monitoring is not available in safe mode.
  • UDP with DDP is used for target discovery (NI-specific protocol).



  • Visit and enter the Info Code RTSecurity to keep informed about security as it relates to NI products.

Unsupported Features

The LabVIEW Real-Time Module does not support certain LabVIEW features for VIs that run on RT targets. For instance, if you attempt to deploy and run a VI that has unsupported functionality on an RT target, the VI might still execute. However, the unsupported functions do not work and return standard LabVIEW error codes. The LabVIEW Real-Time Module does not support the following features on RT targets that run the VxWorks RTOS:

  • ActiveX VIs
  • NI TestStand VIs (ActiveX-based)
  • .NET VIs
  • Report Generation VIs
  • Windows Registry Access VIs
  • Report Express VI (Uses the unsupported Report Generation VIs)
  • Graphics & Sound VIs
  • Database Connectivity VIs
  • Menu functions
  • Cursor VIs
  • IrDA functions
  • System Exec VI
  • Open/Create/Replace File function interactively using a file dialog box
  • Analysis Workspace to Reduce Jitter in Mathematics and Signal Processing VIs
  • Call Library Function Nodes that access an operating system API other than VxWorks
  • Certain Advanced TDMS functions
  • Auto Configure option of the Create Histogram Express VI
  • Clear indicators when called option of the Execution Properties page
  • LabVIEW-built DLLs—VxWorks supports only .OUT libraries, which LabVIEW does not build.
  • Certain MathScript functions
    Note   Certain MathScript functions are supported on RT targets only when you assign the output of the function to a MathScript variable.
  • Profile Buffer Allocations window
  • Output Page of the LabVIEW MathScript Probe window—You can use the rt_debugoutput function to send debug strings to the standard output device instead.
  • Event structures on RT targets do not support events associated with user interface objects, such as VI front panels or controls. For example, associating the Value Change event with a control does not work. RT targets support only user events.
  • Dynamically loading VIs without first compiling for PowerPC platform—To dynamically call a VI on a VxWorks target, you first must build a source distribution in the LabVIEW project. The source distribution must include the VI you want to call dynamically. After you build the source distribution, you can FTP the built source distribution to the target and call the VI dynamically through the VI Server.
  • Latch Until Released and Switch Until Released Boolean mechanical actions—Refer to the KnowledgeBase for information about why these Boolean mechanical actions do not work on RT targets.


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