frmgetwfm.frm

Tektronix TDS3000&TDS3000B series oscilloscope program examples ver3.0

VERSION 5.00
Object = "{648A5603-2C6E-101B-82B6-000000000014}#1.1#0"; "MSCOMM32.OCX"
Begin VB.Form frmGetWfm 
   Caption         =   "Get Waveform"
   ClientHeight    =   2325
   ClientLeft      =   60
   ClientTop       =   345
   ClientWidth     =   4200
   LinkTopic       =   "Form1"
   ScaleHeight     =   2325
   ScaleWidth      =   4200
   StartUpPosition =   3  '窗口缺省
   Begin MSCommLib.MSComm MSComm1 
      Left            =   0
      Top             =   960
      _ExtentX        =   794
      _ExtentY        =   794
      _Version        =   393216
      DTREnable       =   -1  'True
      RThreshold      =   1
   End
   Begin VB.Timer Timer1 
      Enabled         =   0   'False
      Left            =   120
      Top             =   360
   End
   Begin VB.Frame Frame1 
      Caption         =   "Select COMM port"
      Height          =   732
      Left            =   600
      TabIndex        =   2
      Top             =   240
      Width           =   3012
      Begin VB.OptionButton CommPort 
         Caption         =   "COM2"
         Height          =   252
         Index           =   1
         Left            =   1800
         TabIndex        =   4
         Top             =   240
         Width           =   1092
      End
      Begin VB.OptionButton CommPort 
         Caption         =   "COM1"
         Height          =   252
         Index           =   0
         Left            =   240
         TabIndex        =   3
         Top             =   240
         Width           =   1212
      End
   End
   Begin VB.CommandButton cmdEnd 
      Caption         =   "Done"
      BeginProperty Font 
         Name            =   "MS Sans Serif"
         Size            =   9.75
         Charset         =   0
         Weight          =   700
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      Height          =   495
      Left            =   2400
      TabIndex        =   1
      Top             =   1320
      Width           =   1212
   End
   Begin VB.CommandButton cmdStart 
      Caption         =   "Start"
      BeginProperty Font 
         Name            =   "MS Sans Serif"
         Size            =   9.75
         Charset         =   0
         Weight          =   700
         Underline       =   0   'False
         Italic          =   0   'False
         Strikethrough   =   0   'False
      EndProperty
      Height          =   495
      Left            =   600
      TabIndex        =   0
      Top             =   1320
      Width           =   1212
   End
End
Attribute VB_Name = "frmGetWfm"
Attribute VB_GlobalNameSpace = False
Attribute VB_Creatable = False
Attribute VB_PredeclaredId = True
Attribute VB_Exposed = False
Dim SelectedCommPort As Integer

Private Sub cmdEnd_Click()
   End
End Sub

Private Sub cmdStart_Click()
'
'   GetWfm - program to get a waveform from an oscilloscope,
'               convert its data values to absolute voltage measurements,
'               and store these values in an Excell compatible file.
'

' Version 1.0.
'

'
' Initialize the arrays.
'
    Dim IARR%()
    Dim WFARR%()
    Dim VOLTARR!()
    Dim TIMEARR!()
    Dim P As Integer

'
' Disable the start button until we are done.
'
    cmdStart.Enabled = False

' Set up the comm port
'   Set the comm port to generate an event on every character
'       received.
'   Then open the port.
    MSComm1.CommPort = SelectedCommPort
    MSComm1.RThreshold = 1
    MSComm1.PortOpen = True
    
'
'  Turn off the header from query responses.
'
        Call RS232WRITE(MSComm1, "HEADER OFF")
'
'  Set up the data source to be channel 1.
'
        DATSRC$ = "CH1"
        WRT$ = "DATA:SOURCE " + DATSRC$
        Call RS232WRITE(MSComm1, WRT$)
'
'  Set up data encoding to be ribinary and data width to 1.
'
        Call RS232WRITE(MSComm1, "DATA:ENCDG RIBINARY;WIDTH 1")
        
' Print a message on the screen instructing the user to connect
' Channel 1 to the front-panel PROBE COMPENSATION SIGNAL.
'
    
    MSG = " Connect the PROBE COMPENSATION SIGNAL to channel 1" ' Define message.
    Style = vbOKOnly + vbInformation                            ' Define buttons.
    Title = "Probe Connection"                                  ' Define title.
    RESPONSE = MsgBox(MSG, Style, Title)
'
'
'  Set up the recordlength, and the data start and data stop positions.
'  In this example, the entire waveform is obtained so data start and
'  data stop are 1 and 500 respectively.
'
        RL% = 500
        WRT$ = "HORIZONTAL:RECORDLENGTH " + Str$(RL%)
        Call RS232WRITE(MSComm1, WRT$)
        DSTART% = 1
        DSTOP% = RL%
        WFPOINTS% = DSTOP% - DSTART% + 1
        MsgBox "Number of waveform points is " & WFPOINTS%
        'Print "        Number of waveform points is "; WFPOINTS%
        'Print
        WRT$ = "DATA:START " + Str$(DSTART%)
        Call RS232WRITE(MSComm1, WRT$)
        WRT$ = "DATA:STOP " + Str$(DSTOP%)
        Call RS232WRITE(MSComm1, WRT$)
        WRT$ = "HEADER OFF"
        Call RS232WRITE(MSComm1, WRT$)
'
'
'  Make sure setup changes have taken effect and a new waveform is acquired
'
        Call RS232WRITE(MSComm1, "ACQUIRE:STATE RUN")
'
'  Wait for the scope to acquire the waveform.
'
        Call RS232WAITCOM(MSComm1, 14)
'
'  Send the scope a curve query to get waveform data.
'
        Call RS232WRITE(MSComm1, "CURVE?")
'
'
' Read waveform data.
'
' The waveform is formatted as #<x><yyy><data><newline> where
'       <x> is the number of y bytes; for example if yyy = 500, then
'              x = 3
'       <yyy> is the number of bytes to transfer including checksum;
'              if width is 1 then all bytes on bus are single data
'              points; if width is 2 then bytes on bus are
'              2-byte pairs; this program uses width of 1
'       <data> is the curve data
'       <newline> is a single byte newline character at the end of the data
'
       ' RLPREAM$ = Space$(WFPOINTS%)) + 1)
        
        ' Read the waveform data
        Call RS232Read(MSComm1, RLPREAM$)
        Print "123"
'
'
'  Transfer data an array that will have one data element per data
'  point.  Handle the conversion to signed data.
'
        ReDim WFARR%(WFPOINTS%)   ' set up the waveform output array
        For i% = 1 To WFPOINTS%
            P = Asc(Mid(RLPREAM$, i%, 1))
            If P > 128 Then
                P = -(256 - P)
            End If
            WFARR%(i% - 1) = P
        Next i%

'
'
'  Read the waveform preamble.
'  Get the vertical offset and scale multiplier,
'  the trigger point, the horizontal sampling interval
'  and the horizontal units to convert the data points to
'  time and voltage values.
'
        WRT$ = "WFMPRE:" + DATSRC$ + ":YOFF?"
        Call RS232WRITE(MSComm1, WRT$)
        rd$ = Space$(20)
        Call RS232Read(MSComm1, rd$)
        YOFF! = Val(rd$)
        
        WRT$ = "WFMPRE:" + DATSRC$ + ":YMULT?"
        Call RS232WRITE(MSComm1, WRT$)
        rd$ = Space$(20)
        Call RS232Read(MSComm1, rd$)
        YMULT! = Val(rd$)
        
        WRT$ = "WFMPRE:" + DATSRC$ + ":YUNIT?"
        Call RS232WRITE(MSComm1, WRT$)
        YUNIT$ = Space$(20)
        Call RS232Read(MSComm1, YUNIT$)

        WRT$ = "WFMPRE:" + DATSRC$ + ":PT_Off?"
        Call RS232WRITE(MSComm1, WRT$)
        rd$ = Space$(20)
        Call RS232Read(MSComm1, rd$)
        PtOff! = Val(rd$)

        WRT$ = "WFMPRE:" + DATSRC$ + ":XINCR?"
        Call RS232WRITE(MSComm1, WRT$)
        rd$ = Space$(20)
        Call RS232Read(MSComm1, rd$)
        XINCR! = Val(rd$)
        
        WRT$ = "WFMPRE:" + DATSRC$ + ":XUNIT?"
        Call RS232WRITE(MSComm1, WRT$)
        XUNIT$ = Space$(20)
        Call RS232Read(MSComm1, XUNIT$)

'
' Output header (x-, y-units, date, time and source)
' Write out the data to a file called "WFM_DATA.PRN".
        WAVEFL$ = "C:\WFM_DATA.PRN"         ' set up an output file for the data time and voltages
        Open WAVEFL$ For Output As #1
        Print #1, USING; "\\"; XUNIT$; "  ";
        Print #1, USING; "\   \"; YUNIT$; "  ";
        Print #1, "CH1"
'
'
' Process waveform data.
' Write out the data to a file called "WFM_DATA.PRN".
'
        ReDim VOLTARR!(WFPOINTS%) ' set up the voltage output array
        ReDim TIMEARR!(WFPOINTS%) ' set up the time output array
        For i% = 0 To WFPOINTS% - 1
                TIMEARR!(i%) = (i% - PtOff!) * XINCR!
                VOLTARR!(i%) = (WFARR%(i%) - YOFF!) * YMULT!
                Print #1, TIMEARR!(i%), ",", VOLTARR!(i%)
        Next i%
        
        
'  Display the name of the file
        SMSG = "Waveform time and voltage points are in file " & WAVEFL$
        MsgBox SMSG

'
' Close the file and comm port.
'
    Close #1
    MSComm1.PortOpen = False
    cmdStart.Enabled = True
End Sub

'
' Save the users select of a COMM port.
'
Private Sub CommPort_Click(Index As Integer)
    If Index = 0 Then
        SelectedCommPort = 1
    Else
        SelectedCommPort = 2
    End If
End Sub

Private Sub Form_Load()
    SelectedCommPort = 2
    CommPort(1).Value = True
End Sub

Private Sub Timer1_Timer()
    Call MsgBox("Time out occurred!")
    Stop
End Sub