modbus_new_tcp_pi(3) debian man page | unix.com

MODBUS_NEW_TCP_PI(3)						 Libmodbus Manual					      MODBUS_NEW_TCP_PI(3)

NAME
       modbus_new_tcp_pi - create a libmodbus context for TCP Protocol Independent

SYNOPSIS
       modbus_t *modbus_new_tcp_pi(const char *node, const char *service);

DESCRIPTION
       The modbus_new_tcp_pi() function shall allocate and initialize a modbus_t structure to communicate with a Modbus TCP IPv4 or Ipv6 server.

       The node argument specifies the host name or IP address of the host to connect to, eg. 192.168.0.5 , ::1 or server.com.

       The service argument is the service name/port number to connect to. To use the default Modbus port use the string "502". On many Unix
       systems, it's convenient to use a port number greater than or equal to 1024 because it's not necessary to have administrator privileges.

RETURN VALUE
       The modbus_new_tcp_pi() function shall return a pointer to a modbus_t structure if successful. Otherwise it shall return NULL and set errno
       to one of the values defined below.

ERRORS
       EINVAL
	   The node string is empty or has been truncated. The service string is empty or has been truncated.

EXAMPLE
	   modbus_t *ctx;

	   ctx = modbus_new_tcp_pi("::1", "1502");
	   if (ctx == NULL) {
	       fprintf(stderr, "Unable to allocate libmodbus context
");
	       return -1;
	   }

	   if (modbus_connect(ctx) == -1) {
	       fprintf(stderr, "Connection failed: %s
", modbus_strerror(errno));
	       modbus_free(ctx);
	       return -1;
	   }

SEE ALSO
       modbus_new_tcp(3) modbus_new_rtu(3) modbus_free(3)

AUTHORS
       The libmodbus documentation was written by Stephane Raimbault <stephane.raimbault@gmail.com[1]>

NOTES
	1. stephane.raimbault@gmail.com
	   mailto:stephane.raimbault@gmail.com

libmodbus 3.0.3 						    05/26/2012						      MODBUS_NEW_TCP_PI(3)