S820E Microwave Site Master™ Programming Manual : Examples : Visual Basic
Visual Basic
This function can be called in a Visual Basic program. It sends the *IDN? query to the instrument and returns the byte count and ASCII response string.
Rem This example is based on Example 2-1 from the NI-VISA User Manual.
Public Sub IdnMain(ByVal address As String, ByRef byteCount As String, ByRef returnBytes As String)
Const BUFFER_SIZE = 200
Dim stat As ViStatus
Dim dfltRM As ViSession
Dim sesn As ViSession
Dim retCount As Long
Dim buffer As String * BUFFER_SIZE
Rem ***Include visa32.dll as a reference in your project.***
Rem Begin by initializing the system
stat = viOpenDefaultRM(dfltRM)
If (stat < VI_SUCCESS) Then
Rem Error initializing VISA...exiting
MsgBox “Can't initialize VISA”
Exit Sub
End If
Rem Open communication with Device
Rem NOTE: For simplicity, we will not show error checking
Rem TODO: Add error handling.
stat = viOpen(dfltRM, address, VI_NULL, VI_NULL, sesn)
Rem Set the timeout for message-based communication
Rem TODO: Add error handling.
stat = viSetAttribute(sesn, VI_ATTR_TMO_VALUE, 120000)
Rem Ask the device for identification
Rem TODO: Add error handling.
stat = viWrite(sesn, “*IDN?”, 5, retCount)
stat = viRead(sesn, buffer, BUFFER_SIZE, retCount)
Rem TODO: Add code to process the data.
byteCount = retCount
returnBytes = Left(buffer, retCount)
Rem Close down the system
Rem TODO: Add error handling.
stat = viClose(sesn)
stat = viClose(dfltRM)
End Sub