Private Sub tst_1_Click()
Dim Buffer As String
 
MSComm1.Output = vbCrLf
MSComm1.Output = "*IDN?" & vbCrLf
MSComm1.Output = vbCrLf
 
For I = 0 To 4000
 
    DoEvents
    Do
    DoEvents
    Buffer = Buffer + MSComm1.Input
    Loop Until Len(Buffer) > 0
    Text1.Text = Buffer
 
Next I
 
End Sub