private void btnSpeOpen_Click(object sender, RoutedEventArgs e)
        {
            SpectrumAnalyzerType type = (SpectrumAnalyzerType)(this.cmbSpeType.SelectedIndex);
            string addr = this.tbSpeAddr.Text;

            if (!isSpectrumMeterConnected)
            {
                spectrumAnalyzer         = SpectrumAnalyzer.GetInstance(type);
                isSpectrumMeterConnected = spectrumAnalyzer.Connect(addr);
                if (isSpectrumMeterConnected)
                {
                    this.btnSpeOpen.Background = sucessColor;
                }
                else
                {
                    this.btnSpeOpen.Background = normalColor;
                }
            }
            else
            {
                this.btnSpeOpen.Background = sucessColor;
            }
        }