户端页面中读取串口操作

 <object classid="clsid:648A5600-2C6E-101B-82B6-000000000014" id="MSComm1" codebase="C:\WINDOWS\system\MSCOMM32.OCX"
     type="application/x-oleobject" style="left: 54px; top: 14px">
     <param name="CommPort" value="1 " />
     <param name="DTREnable" value="1" />
     <param name="Handshaking" value="0" />
     <param name="InBufferSize" value="1024" />
     <param name="InputLen" value="0" />
     <param name="NullDiscard" value="0" />
     <param name="OutBufferSize" value="512" />
     <param name="ParityReplace" value="63" />
     <param name="RThreshold" value="0" />
     <param name="RTSEnable" value="0" />
     <param name="BaudRate" value="9600" />
     <param name="ParitySetting" value="0" />
     <param name="DataBits" value="8" />
     <param name="StopBits" value="0" />
     <param name="SThreshold" value="0 " />
     <param name="EOFEnable" value="0" />
     <param name="InputMode" value="0" />
 </object>

JS代码 

 //重写 mscomm 控件的唯一事件处理代码
     function MSComm1_OnComm()
     {
         var len=0;;
         if(MSComm1.CommEvent==1)//如果是发送事件
         {
           window.alert("请读条码");//这句正常，说明发送成功了
         }
         else if(MSComm1.CommEvent==2)//如果是接收事件
         {
         //  window.alert(MSComm1.CommEvent);//！ ‘
         //  window.alert(MSComm1.Input);
             document.form1.txtReceive.value=document.form1.txtReceive.value + MSComm1.Input;
         }
         // return false;
     }


 //打开端口并发送命令程序
 function OpenPort()
 {
     if(MSComm1.PortOpen==false)
     {
         MSComm1.PortOpen=true;
         MSComm1.Output="R";//发送命令
     }
     else
     {
       window.alert ("已经开始接收数据!");
     }
 }