Visual Basic Express 2008 ethernet comms

This is a good example that doesn't use any 3rd party libraries.

VB6 and VBA are quite different from VB.Net as far as organization goes. There are no 'modules' per say, so you'll need to use a separate class.

The example that Scott provided is a good start, but there are some optimizations that can be made:

• Use this as part of your own Class Library.

• TcpClient and NetworkStream objects are encapsulated in Using statements so they are properly closed and disposed when they leave the program scope.

• IDisposible is implemented and garbage collection is properly taken care of.

note: this is a quick adaptation from my own code base, so this is in C# and may contain a few typos

VB Usage:

Dim TcpComm as New TcpClientCommClass("127.0.0.1", 80)
Dim tx as string
Dim rx as string

tx = "my message"
rx = TcpComm.Communicate(tx)

C# Usage:

TcpClientCommClass TcpComm = new TcpClientCommClass("127.0.0.1", 80);
string tx = "my message";
string rx = TcpComm.Communicate(tx);

using System;
using System.Net.Sockets;   // for the TcpClient objects
using System.Text;          // for ASCII <-> Byte functions
using System.Diagnostics;   // for debug methods (print, assert)

namespace TcpClientWorkbench
{
    class TcpClientCommClass : IDisposable
    {
        TcpClient client;
        NetworkStream netStream;

        public string Host { get; set; }
        public int Port { get; set; }

        // Instantiate the class using the specified host and port.
        public TcpClientCommClass(string host, int port)
        {
            this.Host = host;
            this.Port = port;
        }

        // Instantiate the class defaulting to the localhost.
        public TcpClientCommClass()
        {
            this.Host = "127.0.0.1";
            this.Port = 80;
        }

        public string Communicate(string message)
        {
            try
            {
                using (client = new TcpClient(Host, Port))
                {
                    using (netStream = client.GetStream())
                    {
                        if ((netStream.CanRead == true) && (netStream.CanWrite))
                        {
                            // Simple transmit example
                            byte[] transmitBuffer = Encoding.ASCII.GetBytes(message);
                            netStream.Write(transmitBuffer, 0, transmitBuffer.Length);

                            // Simple receive example
                            byte[] receiveBuffer = new byte[client.ReceiveBufferSize];
                            netStream.Read(receiveBuffer, 0, client.ReceiveBufferSize);

                            Debug.Print(Encoding.ASCII.GetString(receiveBuffer));
                            return Encoding.ASCII.GetString(receiveBuffer);
                        }
                        else
                        {
                            if (netStream.CanRead == false)
                            {
                                Debug.Print("Can not read from stream");
                            }

                            if (netStream.CanWrite == false)
                            {
                                Debug.Print("Can not write to stream");
                            }
                        }
                    }
                }
            }
            catch (Exception ex)
            {
                Debug.Print(ex.ToString());
            }
        }

        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        ~TcpClientCommClass() 
        {
            Dispose(false);
        }

        protected virtual void Dispose(bool disposing)
        {
            if (disposing) 
            {


                if (netStream != null)
                {
                    netStream.Close();
                    netStream.Dispose();
                }

                if (client != null)
                {
                    client.Close();
                    client = null;
                }
            }            
        }
    }
}

If your looking for input on Visual Basic, C#, or pretty much any other programming language outside the scope of ladder logic and function blocks, I'd try my luck on Stackoverflow.com first.