tcpOpen()

Opens the connection to a TCP/IP server socket.

Synopsis

int tcpOpen(string host, unsigned port [, time timeout]);

Parameters

Parameter	Description
host	Name of the host, to which the function establishes a connection, for example, eiwnt094
port	Number of the port, for example, 8080
timeout	Timeout for establishing the connection. This parameter is optional. Default is 5 seconds.

Return value

The socket number of the opened TCP/IP connection.

tcpOpen() returns the socket number.

The return value of tcpOpen() must be used for the socket parameter of tcpWrite().

Use the function getLastError() to test if the function was executed successfully.

In case of an error, -1 will be returned.

Errors

Missing or wrong arguments.

The TCP/IP server socket has already been opened (Close with tcpClose()).

Details

Opens the connection to a TCP/IP Server socket.

You can open up to 255 connections at the same time.

main()
{
  string computerNam= "abc9GC5223TU7", data;
  unsigned Portnumb= 1025;
  int socket, modWrite, modClose, modRead;
  time t = 10;

  //Open-> Write-> Close
  socket = tcpOpen(computerNam, Portnumb);
  dyn_errClass err=getLastError();
  DebugN(err);
  DebugN("Open: " + socket + computerNam+ Portnumb);
  DebugN("Delay");
  delay(5);

  //Write
  modWrite= tcpWrite(socket, "TEST");
  DebugN("Write: " + modWrite);
  DebugN("Delay");
  delay(5);

  modRead = tcpRead(socket, data, t);
  DebugN("Read: " + modRead);
  DebugN("Read data: " + data);
  DebugN("Finish");

  //Close
  modClose= tcpClose(socket);
  DebugN("TcpClose: " + modClose);
  DebugN("Delay");
  delay(5);

  //Try to write again. Writing does not work anymore
  modWrite= tcpWrite(socket, "WRITING DOES NOT WORK ANYMORE");
  DebugN("Write does not work anymore: " + modWrite);
  DebugN("Delay");
  delay(5);
}

Assignment

Communication Functions

Availability

CONTROL