Technical data

5 Application Programs
Example Program for Excel 97
144 E364xA User’s and Service Guide
Private Function OpenPort()
Dim GPIB_Address As String
Dim COM_Address As String
If bGPIB Then
GPIB_Address = "5" ' Select GPIB address between 0 to 30
Else
COM_Address = "1" ' Set the number to 2 for COM2 port
End If
ErrorStatus = viOpenDefaultRM(defaultRM) ' Open the VISA session
If bGPIB Then
ErrorStatus = viOpen(defaultRM, "GPIB0::" & GPIB_Address & "::INSTR", _
0, 1000, power_supply)
Else
ErrorStatus = viOpen(defaultRM, "ASRL" & COM_Address & "::INSTR", _
0, 1000, power_supply)
SendSCPI "System:Remote"
End If
CheckError "Unable to open interface"
End Function
'*********************************************************************************
' This routine sends a SCPI command string to the GPIB interface or RS-232 interface.
' If the command contains a question mark, the response is read, and returned
'**********************************************************************************
Private Function SendSCPI(command As String) As string
Dim commandString As String ' Command passed to power supply
Dim ReturnString As String ' Store the string returned
Dim crlfpos As Integer ' Location of any nul’s in Read Buffer
Dim ReadBuffer As String * 512 ' Buffer used for returned string
Dim actual As Long ' Number of characters sent/returned
commandString = command & Chr$(10) ' The instrumented by linefeed
ErrorStatus = viWrite(power_supply, ByVal commandString, Len(commandString), _
actual)
CheckError "Can’t Write to Device"
If bGPIB = False Then
delay 0.5
End If
If InStr(commandString, "?") Then
ErrorStatus = viRead(power_supply, ByVal ReadBuffer, 512, actual)
CheckError "Can’t Read From Device"
ReturnString = ReadBuffer
crlfpos = InStr(ReturnString, Chr$(0))
If crlfpos Then
ReturnString = Left(ReturnString, crlfpos - 1)
End If
SendSCPI = ReturnString
End If
End Function