/// <summary>
/// Initializes a new instance of the <see cref="ModbusServer"/> class.
/// </summary>
/// <param name="port">The port to listen. (Default: 502)</param>
/// <param name="listenAddress">The ip address to bind on. (Default: <see cref="IPAddress.IPv6Any"/>)</param>
/// <param name="logger"><see cref="ILogger"/> instance to write log entries. (Default: no logger)</param>
/// <param name="requestHandler">Set this request handler to override the default implemented handling. (Default: serving the data provided by Set* methods)</param>
public ModbusServer(int port = 502, IPAddress listenAddress = null, ILogger logger = null, ModbusTcpRequestHandler requestHandler = null)
{
ListenAddress = listenAddress;
if (ListenAddress == null)
{
ListenAddress = IPAddress.IPv6Any;
}
if (port < 0 || port > 65535)
{
throw new ArgumentOutOfRangeException(nameof(port));
}
try
{
var listener = new TcpListener(ListenAddress, port);
listener.Start(10);
Port = ((IPEndPoint)listener.LocalEndpoint).Port;
listener.Stop();
}
catch (Exception ex)
{
throw new ArgumentException(nameof(port), ex);
}
this.logger = logger;
this.requestHandler = requestHandler ?? HandleRequest;
Initialization = Task.Run(() => Initialize());
}
public void StartMultiUnit(IPEndPoint localEndpoint)
{
var tcpClientProvider = new DefaultTcpClientProvider(localEndpoint);
base.StopProcessing();
base.StartProcessing();
var requestHandlers = new List <ModbusTcpRequestHandler>();
// accept clients asynchronously
/* https://stackoverflow.com/questions/2782802/can-net-task-instances-go-out-of-scope-during-run */
Task.Run(async() =>
{
while (!this.CTS.IsCancellationRequested)
{
// There are no default timeouts (SendTimeout and ReceiveTimeout = 0),
// use ConnectionTimeout instead.
var tcpClient = await tcpClientProvider.AcceptTcpClientAsync();
var requestHandler = new ModbusTcpRequestHandler(tcpClient, this, handleUnitIdentifiers: true);
lock (this.Lock)
{
if (this.MaxConnections > 0 &&
/* request handler is added later in 'else' block, so count needs to be increased by 1 */
this.RequestHandlers.Count + 1 > this.MaxConnections)
{
tcpClient.Close();
}
else
{
this.RequestHandlers.Add(requestHandler);
}
}
}
}, this.CTS.Token);
}