MSComm控件

1,把com通讯设置为二进制然后打开端口：
MSComm1->InputMode=comInputModeBinary;
MSComm1->PortOpen =true;
2，建立存储空间：
OleVariant Buff;
int n=4;
int byte[4]={0xFF,0xFE,0xF4,0xFD};
Buff=VarArrayCreate(OPENARRAY(int,(0,n-1)),varByte);//关键是后面要设置为varByte
3，数据转换
for (int i=0;i<5;i++)
{
Buff.PutElement(byte[i],i);
}
4，发送
MSComm1->Output =Buff;

delphi

var
senddata:array[1..10] of char;
reData:array of Variant;
sendstr:string;
restr:string;
i:longint;
begin
mscomm1.CommPort := 1; //指定端口
mscomm1.Settings := '9600,N,8,1'; //其它参数
mscomm1.InBufferSize := 1024; //接收缓冲区
mscomm1.OutBufferSize := 1024; //发送缓冲区
mscomm1.InputMode := comInputModeBinary; //接收模式
mscomm1.InputLen := 0; //一次读取所有数据
mscomm1.SThreshold := 0; //一次发送所有数据
mscomm1.InBufferCount := 0; //清空读取缓冲区
mscomm1.OutBufferCount := 0; //清空发送缓冲区
mscomm1.PortOpen:=true; //打开端口
MSComm1.RThreshold := 16; //设置接收多少字节开产生oncomm事件
senddata[1]:=chr($06); //要发送的数据
senddata[2]:=chr($03);
senddata[3]:=chr($00);
senddata[4]:=chr($03);
senddata[5]:=chr($10);
sendstr:='';
for i:=1 to 5 do
sendstr:=sendstr + senddata[i];
mscomm1.output:=sendstr; //发送数据
i:=0;
bzw:=false;

repeat
sleep(10);
Application.ProcessMessages;
i := i + 1;
If i > 30000 Then
begin
showmessage('发送超时!');
break;
end;
Until bzw = true;
redata:=mscomm1.Input; 接收数据
restr:='';
for i:=0 to vararrayhighbound(redata,1) do
restr:=restr + inttohex(redata[i],2)+' ';
mscomm1.PortOpen:=false;
flatmemo1.Text:=restr;
end;
//oncomm事件
procedure TForm1.MSComm1Comm(Sender: TObject);
begin
case mscomm1.CommEvent of
comEvReceive: bzw := true;
end;
end;

最后，记事发布软件时要带上Mscomm32.ocx文件。

1.一般情况下向发送缓冲区内只能发送字符串.如果你要从缓冲区讯出一个16进制的数.我建议你在发送时将FF FE FD F9 F4 变成"FF FE FD F9 F4 " 变成一个字符串发送
2.在接收时也以字符串的形式接收,接收完之后之后Hex(number)转一下.

16进制发送即2进制发送，需用Byte数组来完成，你把"FFFEF4FD"写在TxtSend文本框内
Private Sub cmdSendHex_Click() '16进制发送
Dim sj() As Byte
Dim sj_Txt As String
Dim i As Integer
sj_Txt = TxtSend
ReDim sj(Len(sj_Txt) / 2 - 1)
For i = 0 To Len(sj_Txt) - 1 Step 2
sj(i / 2) = Val("&H" & Mid(sj_Txt, i + 1, 2))
Next
If MSComm1.PortOpen = True Then
MSComm1.Output = sj
Else
MSComm1.PortOpen = True
MSComm1.Output = sj
End If
End Sub

mscomm1.output cstr(text1.text)