SerialPort问题

各位高手，大家好。问个串口的问题，如下：  
    我使用vs2005中的SerialPort类来实现串口。使用串口调试助手显示：在我打开串口的时候，串口会自动发数据“SL_Open 0x30860 (0 opens)”。在处理DataReceived事件的时候，我使用了MessageBox来显示我收到的数据，在我点击MeaaageBox上的“OK”来关闭MessageBox的时候，串口调试助手收到“+SL_GetStatus 0x30860”的信息。可是我没有发送任何信息。我的代码如下：private void serialPort1_DataReceived(object  sender,System.IO.Ports.SerialDataReceivedEventArgs e)
        {
            if (Send_Flag == true)//判断是否读取数据
            {
                Send_Flag = false;
                serialPort1.Read(lpBuffer, 0, 10);
                m_v[0] = Convert.ToUInt32((lpBuffer[0] << 4) + (lpBuffer[1] & 0x0f));
                m_v[1] = Convert.ToUInt32((lpBuffer[2] << 4) + (lpBuffer[3] & 0x0f));
                m_v[2] = Convert.ToUInt32((lpBuffer[4] << 4) + (lpBuffer[5] & 0x0f));
                m_v[3] = Convert.ToUInt32((lpBuffer[6] << 4) + (lpBuffer[7] & 0x0f));
                m_v[4] = Convert.ToUInt32((lpBuffer[8] << 4) + (lpBuffer[9] & 0x0f));                m_vol[0] = Convert.ToSingle((float)(m_v[0]) * 5 / 4095);
                m_vol[1] = Convert.ToSingle((float)(m_v[1]) * 5 / 4095);
                m_vol[2] = Convert.ToSingle((float)(m_v[2]) * 5 / 4095);
                m_vol[3] = Convert.ToSingle((float)(m_v[3]) * 5 / 4095);
                m_vol[4] = Convert.ToSingle((float)(m_v[4]) * 5 / 4095);
                for (int i = 0; i < 5; i++)
                {
                    string str = string.Format("{0:#.000}", m_vol[i]);
                    MessageBox.Show(str);
                }
            }
            else
            {
                serialPort1.BaseStream.Flush();
                return;
            }
                        }
 private void button3_Click(object sender, EventArgs e)//发送数据
        {
            Send_Flag = true;
            
                if (!serialPort1.IsOpen)
                {
                    serialPort1.Open(); 
                                                           
                    serialPort1.Write(fre, 0, 5);
                    
                }
                else
                {
                    
                   
                    serialPort1.Write(fre, 0, 5);
                                    }
        }