private void OnButtonClick_SendAPDU(object sender, EventArgs e)
        {
            // Example: GetVersion(1)  -> APDUSendData = 60
            // >>  02 00 0B FF B2 BE 83 00 60 16 59
            // <<  02 00 13 00 B2 00 02 00 00 AF 04 01 01 01 00 1A 05 83 6B   OK

            // Variables
            byte[] APDUSendData;
            string cProtocol;

            cProtocol = this.maskedTextBox_APDU.Text;
            if (cProtocol.Length == 0)
            {
                this.textBox_status_out.Clear();
                this.textBox_status_out.AppendText("No or to less data in Protocol! -> use data format: 112233....");
                return;
            }

            if (cProtocol.Length % 2 != 0)
            {
                this.textBox_status_out.Clear();
                this.textBox_status_out.AppendText("Wrong protocol format or protocol length - Length must be even\nUse data format: 112233....)!)");
                return;
            }

            APDUSendData = new byte[cProtocol.Length / 2];

            APDUSendData = FeHexConvert.HexStringToByteArray(cProtocol);

            try
            {
                // Set APDU data
                APDU_Prot.SetApdu(APDUSendData);
                // send APDU
                fedm.SendTclApdu(APDU_Prot);
            }
            catch (Exception ex)
            {
                MessageBox.Show(this, ex.ToString(), "Error");
            }
        }