PortExists

Retrieves a boolean True/False indicating if a given port exists

ReadOnly at Runtime.

Only available using the Comm32 ocx. Not supported by MSComm32

Syntax result = object.PortExists(value)         object Name of the communications control.   value Numerical Com port number in the range 1 to 256   result A Boolean - PortExists True or False         Examples       If Comm1.PortExists(5) Then      MsgBox("Com5 exists")   Else      MsgBox("Com5 does not exist") End If '// Does Com5 exist ?

Remarks:
The only way that Micorosoft's MSComm32 ocx can check if a port exists is by attempting to open it and handling the error if the port doesn't exist. This new Comm32 control allows you to check whether a port exists without touching the port - This is a 'non-intrusive' read-only test meaning you can even do this if the port is busy.

'// We're going to populate a listbox with the short "Com" names of com ports that are known to exist.

Private Sub PopulateList( )
Dim i as Long

       List1.Clear
       '// In this example we'll test for ports up to 32 - you can test up to 256 if you want.
       For i = 1 To 32
              If Comm1.PortExists( i ) = True Then
                     '// This port exists so add it to the list
                     List1.AddItem "Com" & i
                  Else
                     '// This port does not exist
              End If
       Next i
 
End Sub

See also DeviceName and InstalledDrivers properties.