Send and Receive from .NET to a Serial Device "Like" a VT 100

Question

I have a serial device that is designed to receive and reply to commands from a VT100 type terminal. I can use any number of 'terminal emulators' to operate this device. But what I WANT to do is send a series of commands from a .NET Windows application and receive the replies back the same application so that I can drive a GUI that will be 'dirt simple' for the operators. What I don't want is another Terminal Emulator. It appears that using "System.IO.Serial.SerialPort" I can open a connection, send a message, assign a delegate to receive a message, actually receive a message...but the message that I send (a command) is not interpreted as I expect (when I inspect the status of the device with a terminal emulator the status does not match the command sent via .Net) and the message I receive back is not in a format I can decipher.

What I believe I need to do is properly encode the command and properly decode the response...but I can find no documentation that clearly explains how to do this.

(I'm working in C#, but any .Net example would be appreciated)

The code I am working with to prototype this is:

using System;
using System.IO.Ports;
using System.Text;

namespace busmanager
{
    public class buslink
    {
        SerialPort _serialPort;
        Boolean _echo;
        Delegate _receiver;

        //Defaut Ctor:
        public buslink(Delegate Receiver)
        {
            String[] SerialPorts = System.IO.Ports.SerialPort.GetPortNames();
            if (SerialPort.GetPortNames().Length > 0)
            {
                SetChannel(PortDefinitions.GetDefaults(SerialPort.GetPortNames()[0]), Receiver);
            }
            else
            {
                throw new Exception("Unable to connect to serial port");
            }
        }

        //Custom Ctor: for externally defined PortDefinitions
        public buslink(PortDefinitions PortDefinitions, Delegate Receiver)
        {
            SetChannel(PortDefinitions, Receiver);
        }

        private void SetChannel(PortDefinitions PortDefinitions, Delegate Receiver)
        {
            _serialPort = new SerialPort()
            {
                PortName = PortDefinitions.PortName,
                //BaudRate = PortDefinitions.BaudRate,
                Parity = PortDefinitions.Parity,
                StopBits = PortDefinitions.StopBits,
                DataBits = PortDefinitions.DataBits,
                Handshake = PortDefinitions.Handshake,
                ReadTimeout = PortDefinitions.ReadTimeout,
                WriteTimeout = PortDefinitions.WriteTimeout,
                NewLine = "\n",
                Encoding = System.Text.Encoding.ASCII,
                DtrEnable = true,


            };
            _echo = PortDefinitions.Echo;
            _serialPort.DataReceived += new SerialDataReceivedEventHandler(_serialPort_DataReceived);
            _serialPort.Open();
            _receiver = Receiver;

        }

        void _serialPort_DataReceived(object sender, SerialDataReceivedEventArgs e)
        {
            byte[] c = new byte[1000];
           int x = _serialPort.Read(c,0,1000);
            string d = c.ToString();

            _receiver.DynamicInvoke(_serialPort.ReadExisting());
        }

        public string Send(string Cmd)
        {
            Cmd = Cmd.ToUpper();
            byte[] sendBytes = Encoding.ASCII.GetBytes(Cmd);
            try
            {
                if (ValidateCmd(Cmd))
                {
                    _serialPort.WriteLine(Cmd);
                    if (_echo)
                    {
                        return "ECHO: " + Cmd;
                    }
                }
            }
            catch (Exception ex)
            {
                throw ex;
            }

            return string.Empty;

        }

        private bool ValidateCmd(string Cmd)
        {
            return true;
        }



        public void Dispose()
        {
            _serialPort.Close();
            _serialPort.Dispose();
        }
    }

    public struct PortDefinitions
    {
        public string PortName { get; set; }
        public int BaudRate { get; set; }
        public Parity Parity { get; set; }
        public StopBits StopBits { get; set; }
        public int DataBits { get; set; }
        public Handshake Handshake { get; set; }
        public int ReadTimeout { get; set; }
        public int WriteTimeout { get; set; }
        public bool Echo { get; set; }

        public static PortDefinitions GetDefaults(string PortName)
        {
            return new PortDefinitions()
                                        {
                                            PortName = PortName.ToUpper(),
                                            BaudRate = 9600,
                                            Parity = Parity.None,
                                            StopBits = StopBits.One,
                                            DataBits = 8,
                                            Handshake = Handshake.None,
                                            ReadTimeout = 1000,
                                            WriteTimeout = 1000,
                                            Echo = true
                                        };
        }


    }


}

The device is proprietary, but the commands it accepts are: InX OutY (where X and Y are ports on the device and a connection is created between the In and the Out Ports) Status All (shows the status of all the inputs

Answer 1

You have your newline definition set wrong. You have NewLine = "/N", but you almost certainly need it to be "\r\n" or "\n".