udp_open

#include <rtl.h>

BOOL udp_open (
    U8  socket,      /* Socket handle to use for communication. */
    U16 locport);    /* Local port to use for communication. */

The udp_open function opens the UDP socket identified by the argument socket for communication. The argument locport specifies the local port that is to be used to send and receive data packets.

The udp_open function is in the RL-TCPnet library. The prototype is defined in rtl.h.

note

• If you specify 0 for locport, TCPnet automatically allocates the first free UDP port for communication.

The udp_open function returns __TRUE if the socket is opened successfully. Otherwise, the function returns __FALSE.

udp_close, udp_get_socket

#include <rtl.h>

U8 udp_soc;

U16 udp_callback (U8 socket, U8 *remip, U16 remport, U8 *buf, U16 len) {
  /* This function is called when UDP data is received */

  /* Process received data from 'buf' */
   ..
  return (0);
}

void main (void) {

  init ();
  /* Initialize the TcpNet */
  init_TcpNet ();
  udp_soc = udp_get_socket (0, UDP_OPT_SEND_CS | UDP_OPT_CHK_CS, udp_callback);
  if (udp_soc != 0) {
    /* Open UDP port 1000 for communication */
    udp_open (udp_soc, 1000);
  }

  while (1);
    /* Run main TcpNet 'thread' */
    main_TcpNet ();
     ..
  }
}