NI-VISA 15.0 HelpEdition Date: June 2015Part Number: 370131S-01»The maximum number of serial ports that NI-VISA currently supports on any platform is 256. The default numbering of serial ports is system dependent, as shown in the following table. PlatformMethodWindows 7/Vista/XP/Server 2008 R2/Server 2003 R2All COM and LPT ports are automatically detected when you call viFindRsrc.
Labview Device Drivers
The VISA interface number may not equal the COM port number.LabVIEW RTAll COM ports are automatically detected when you call viFindRsrc.LabVIEW PDAAll COM ports are automatically detected when you call viFindRsrc.Mac OS XAll COM ports are automatically detected when you call viFindRsrc.LinuxASRL1-ASRL4 access /dev/ttyS0 – /dev/ttyS3.If you need to know programmatically which ASRL INSTR resource maps to which underlying Serial port, the following code will retrieve and display that information. Private Declare Function viGetAttrString Lib 'VISA32.DLL' Alias '#133' (ByVal vi As ViSession, ByVal attrName As ViAttr, ByVal strValue As Any) As ViStatusPrivate Sub vbMain Dim statDim dfltRMDim sesnDim fListDim rsrcNameDim instrDescDim nListAs ViStatusAs ViSessionAs ViSessionAs ViFindListAs String. VIFINDBUFLENAs String. VIFINDBUFLENAs Longstat = viOpenDefaultRM(dfltRM)If (stat.