<p>用COMMUNICATION控件進(jìn)行數(shù)據(jù)采集（學(xué)習(xí)筆記）</p>
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<p>關(guān)鍵詞：VBScript, Visual Basic, Visual C++</p>
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<p>用COMMUNICATION控件實(shí)現(xiàn)數(shù)據(jù)采集</p>
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<p>private Sub form_load()</p>
<p>    MSComm1.COMMPORT = 2                    注釋：com2</p>
<p>    MSComm1.settings = "9600,N,8,1"         注釋：9600 為波特率，n 缺省的奇偶校驗(yàn)值，8 為數(shù)據(jù)位數(shù)，1 為停止位數(shù)。</p>
<p>    MSComm1.InBufferSize = 1024             注釋：接收緩沖區(qū)的大小</p>
<p>    MSComm1.OutBufferSize = 512             注釋：傳輸緩沖區(qū)的大小</p>
<p>    MSComm1.InputLen = 0                    注釋：初始化接收緩沖區(qū)讀取的字符數(shù)</p>
<p>    </p>
<p>    MSComm1.portopen=true                   注釋：打開串口</p>
<p>end sub</p>
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<p>Private Sub command1_click()  </p>
<p>    Dim instring As Byte</p>
<p>    </p>
<p>    h$ = Chr$(13) & Chr$(10) & Chr$(13) & Chr$(10)</p>
<p>    On Error Resume Next</p>
<p>    </p>
<p>    注釋：在這里進(jìn)行串口通訊（RS485）</p>
<p>   </p>
<p>    address="36"   注釋：終端地址</p>
<p>    Lx1 = Chr$(var(address): Lx2 = Chr$(2): Lx3 = Chr$(1)</p>
<p>    MSComm1.Output = Lx1 & Lx2 & Lx3 注釋：向終端發(fā)命令，等待終端傳輸數(shù)據(jù)</p>
<p>    MSComm1.InBufferCount = 0    ’接受緩沖清零</p>
<p>    注釋：接收終端發(fā)出的數(shù)據(jù)</p>
<p>    Dtime1 = Timer</p>
<p>    Do            </p>
<p>        Dtime2 = Timer</p>
<p>        If Dtime2 - Dtime1 < 2 Then</p>
<p>            DoEvents</p>
<p>        Else</p>
<p>            Response = MsgBox("終端沒有數(shù)據(jù)輸出！" & h$ , vbOKOnly + vbExclamation, "警告")</p>
<p>            Exit Sub</p>
<p>        End If</p>
<p>    Loop Until MSComm1.InBufferCount >0 ‘若接受緩沖區(qū)等待的字符數(shù)大于零，則接收到了數(shù)據(jù)</p>
<p>        </p>
<p>    MSComm1.InputLen = 1 ‘從接受緩沖區(qū)要讀取的字符數(shù)</p>
<p>    Instring = MSComm1.Input</p>
<p>end sub</p>
<p> </p>