<?php
$rs232_sock = socket_create(AF_INET, SOCK_STREAM, SOL_TCP);
$result = socket_connect($rs232_sock, '10.0.1.155', '4999');
$rs232_in = pack("H*" ,'02'.bin2hex('PON').'03');
socket_write($rs232_sock, $rs232_in, strlen($rs232_in));
?>