Using LabWindows/CVI Libraries in RT Applications

To build a DLL that you can run on a real-time (RT) target, you must select Real-time only in the Run-time support option of the Target Settings dialog box.

If you select Real-time only, the project does not link to the entire set of LabWindows/CVI libraries but instead links to a smaller set of LabWindows/CVI built-in library functions that are supported in RT applications.

LabWindows/CVI Libraries

The following libraries and functions are supported in RT applications:

• Analysis Library or Advanced Analysis Library
• ANSI C Library, with the following exceptions:

  Note  Only the "C" locale is recognized, and all case-sensitive functions, such as stricmp and tolower, perform conversions only from characters a-z to characters A-Z, and vice-versa, and perform comparisons using only this set of characters. Locale-specific case sensitivity is not honored.

  • Any functions that interact with the keyboard or that require user input are not available.
  • The multibyte to wide-character conversion functions mbtowc and mbstowcs are not available. The wide-character to multibyte conversion functions wctomb and wcstombs are not available.
• Formatting and I/O Library, with the following exceptions:
  • ArrayToFile
  • FileToArray
• Internet Library, with the following exceptions:

  Note  The Internet Library is available only in the LabWindows/CVI Full Development System.

  • InetLaunchDefaultWebBrowser
  • InetPing
• Network Streams Library
• Network Variable Library, with the following exception:
  • CNVVariableEngineIsRunning
• Real-Time Utility Library, with the following exceptions:
  • GetRTSystemInfo
  • FindAllRTSystemsOnSubnet
  • RTSystemSelectPopup
  • System Configuration class
  • System Replication class
• TCP Support Library
• TDM Streaming Library, with the following exceptions:
  • TDMS_AdvancedAsyncRead
  • TDMS_AdvancedAsyncWrite
  • TDMS_ConfigureAsyncReads
  • TDMS_ConfigureAsyncWrites
  • TDMS_GetAsyncReadStatus
  • TDMS_GetAsyncWriteStatus
  • TDMS_ReserveFileSize
• UDP Support Library
• The following functions in the User Interface Library:
  • PostDeferredCall
  • PostDeferredCallToThread
  • ProcessSystemEvents
• The following functions in the Utility Library:
  • All functions in the Multithreading class
  • All functions in the Debugging and Run-time Error Reporting class, with the following exception:
    • CVIDynamicMemoryInfo
  • All functions in the Date/Time class
  • Beep
  • Cls
  • CVIRTEHasBeenDetached
  • GetDir
  • InStandaloneExecutable
  • RoundRealToNearestInteger
  • SetDir
  • TruncateRealNumber

Note  All the functions that are supported in RT applications are multithread safe.

LabWindows/CVI Tools Library (Toolslib) Instrument Drivers

The following Toolslib instrument drivers are supported in RT applications:

• Asynchronous Timers
• Reading/Writing .ini–Style Files, with the following exceptions:
  • Ini_ReadFromRegistry
  • Ini_WriteToRegistry
• Regular Expressions
• The following functions in the Programmer's Toolbox:
  • All functions in the Miscellaneous class, with the following exceptions:
    • GetFileCLibTime
    • GetGeneralErrorString
    • InternationalFileTime
    • InternationalFileDate
    • NetworkVariablePopup
    • OpenDocumentInDefaultViewer
    • ShowHtmlHelp
    • StartPCSound
    • StopPCSound
  • All functions in the Time Conversions class
  • All functions in the String Handling class
  • All functions in the File class, with the following exceptions:
    • SaveBitmapToFile
    • SaveCtrlDisplayToFile
    • SavePanelDisplayToFile
  • All functions in the Searching and Sorting class
  • All functions in the Lists class
  • All functions in the Hash Tables class
  • All functions in the Memory Block Handles class
  • All functions in the Constants and Conversions class
  • All functions in the Special Double Precision Numbers and Functions class
  • All functions in the Callback Posting class, with the following exception:
    • PostDelayedCall
  • All functions in the Endianess class

Additional Libraries

You also can link a Real-time only project to the following libraries, which may require you to install additional components on the RT target.

• RS-232 Library—You must install NI-Serial on the RT target using the Remote Systems item in NI Measurement & Automation Explorer (MAX).
• Hardware Libraries—You must install the appropriate driver for any hardware library that you use in an RT application. The following hardware libraries are supported in RT applications:
  • VISA Library
  • NI-DAQmx Library
  • Traditional NI-DAQ Library (with limitations)
  • NI-DMM
  • NI-Scope
  • NI-FGEN
  • NI-Switch
  • NI-HSDIO
  • NI-CAN

Notes Additional driver support might have been added since this product was released. Contact National Instruments for an up-to-date list of supported drivers. If NI-DAQmx 8.0 or earlier is installed on the local computer and you link the project to the LabWindows/CVI NI-DAQmx Library, you must manually download the NI-DAQmx run-time DLL for RT (\bin\nicaip.dll) to the \ni-rt\system\ folder on the RT target using FTP. You do not need to download this DLL if NI-DAQmx 8.1 or later is installed.

If you use an external compiler and want to use functions that are supported in RT applications, include CVIversion\extlib\msvc\cvi_lvrt.lib in the external compiler project instead of cvirt.lib and cvisupp.lib. Remember that when you use an external compiler, you link to that compiler's ANSI C library.