s2l9.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
'**********************************************************************
'* S2L9.bas - (Section 2, Lesson 9) REMOTE ENABLING AND DISABLING OF A
'*                                  CHANNEL
'*        This is the RTDX Host Client for Section 2, Lesson 9
'*
'* This example enables the target channel ochan, receives integer
'* value 5 from the target, and disables the channel
'**********************************************************************

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.


Const CHANNEL_NAME = "ochan"

Sub main()
    
    Dim rtdx As Object
    
    Dim data As Long
    Dim status As Long
    Dim nummsgs As Long
    Dim i As Long

    On Error GoTo Error_Handler
    
    Set rtdx = CreateObject("RTDX")

    '******************************************************************
    ' Insert code from Step #3 here - enable channel for target
    '                                 writes
    '******************************************************************


    If status <> Success Then
        Debug.Print "enabling of channel ochan failed"
        GoTo Error_Handler
    End If
    
    status = rtdx.Open(CHANNEL_NAME, "R")

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

    status = rtdx.GetNumMsgs(nummsgs)
    
    If status <> Success Then
        Debug.Print "GetNumMsgs returned failure"
        GoTo Error_Handler
    End If
    
    For i = 1 To nummsgs
        status = rtdx.ReadI4(data)
        Select Case (status)
            Case Success
                Debug.Print "Value " & _
                            data & _
                            " was received from the target "
            Case ENoDataAvailable
                Debug.Print "No data is currently available"
            Case EEndOfLogFile
                Debug.Print "End of log file has been detected"
            Case Failure
                Debug.Print "ReadI4 returned failure"
                Exit For
            Case Else
                Debug.Print "Unknown return code"
                Exit For
        End Select
    Next i

    '******************************************************************
    ' Insert code from Step #4 here - disable channel from target
    '                                 writes
    '******************************************************************


    status = rtdx.Close()
    
    If status <> Success Then
        Debug.Print "enabling of channel ochan failed"
        GoTo Error_Handler
    End If
    
    Set rtdx = Nothing
    
    Exit Sub

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

End Sub