private void bRfQuery_Click(object sender, EventArgs e)
        {
            byte pwr  = 0;
            byte freq = 0;

            int status;

            status = Api.GetRf(ref pwr, ref freq);
            if (status != 0)
            {
                lInfo.Items.Add("Get Rf settings failed!");
                return;
            }
            tRfPwr.Value          = pwr;
            cRfFreq.SelectedIndex = freq;
            lInfo.Items.Add("Get Rf settings success!");
        }