s2l3.bas

德州仪器公司的6000系列的程序示例,可以看看实现什么功能,如果需要可以继续上传,配套有电子版说明

Option Explicit
'**********************************************************************
'* S2L3.bas - (Section 2, Lesson 3) RECEIVING ENTIRE MESSAGES USING
'*                                  SAFEARRAYS
'*            This is the RTDX Host Client for Section 2, Lesson 3
'*
'* This example receives integer values 1-10 from the target
'**********************************************************************

Const Success = &H0                     ' Method call is valid
Const Failure = &H80004005              ' Method call failed
Const ENoDataAvailable = &H8003001E     ' No data was available.
                                        ' However, more data may be
                                        ' available in the future.
Const EEndOfLogFile = &H80030002        ' No data was available
                                        ' The end of the log file has
                                        ' been reached.

Sub main()
    
    Dim rtdx As Object
    '******************************************************************
    ' Insert code from Step #3 here - to declare a variable of type
    '                                 Variant.  This variable contains
    '                                 a pointer to a SAFEARRAY
    '******************************************************************


    Dim status As Long
    Dim i As Long

    On Error GoTo Error_Handler

    ' Create an instance of the RTDX COM object
    Set rtdx = CreateObject("RTDX")

    ' Open channel ochan for reading
    status = rtdx.Open("ochan", "R")

    If status <> Success Then
        Debug.Print "Opening of channel ochan failed"
        Goto Error_Handler
    End If

    Do
        '**************************************************************
        ' Insert code from Step #4 here - to read a message (32-bit
        '                                 integer array) from the
        '                                 target
        '**************************************************************

 
        Select Case (status)
            Case Success

                '******************************************************
                ' Insert code from Step #5 here - to print each element
                '                                 in the array
                '******************************************************



            Case ENoDataAvailable
                Debug.Print "No data is currently available"
            Case EEndOfLogFile
                Debug.Print "End of log file has been detected"
            Case Failure
                Debug.Print "ReadSAI4 returned failure"
                Exit Do
            Case Else
                Debug.Print "Unknown return code"
                Exit Do
        End Select
    Loop Until status = EEndOfLogFile

    ' Close the channel
    status = rtdx.Close()

    ' Release the reference to the RTDX COM object
    Set rtdx = Nothing
    
    Exit Sub

Error_Handler:
Debug.Print "Error in COM method call"
Set rtdx = Nothing

End Sub