void _spManager_NewSerialDataRecieved(object sender, SerialDataEventArgs e) { if (this.InvokeRequired) { this.BeginInvoke(new EventHandler <SerialDataEventArgs>(_spManager_NewSerialDataRecieved), new object[] { sender, e }); return; } int maxTextLength = 1000; // maximum text length in text box if (tbData.TextLength > maxTextLength) { tbData.Text = tbData.Text.Remove(0, tbData.TextLength - maxTextLength); } string readData = Encoding.ASCII.GetString(e.Data); tbData.AppendText("Read on " + inPortNameComboBox.Text + " : " + readData + "\r\n"); tbData.AppendText(_spManager.Check(readData) + "\r\n"); tbData.ScrollToCaret(); }