I am using SocketServer.class.php for recieving data from and sending to the remote client from my server. It works with just one client perfectly. The client being a digital meter which sends data over TCP/IP using a GPRS Modem connected to it. Each meter is distinguished using it's meter ID, which ranges from 1 to 247 and the data is passed and recived in ASCII. The PHP Code is run in a windows command shell and saves the input readings to the database. Now when trying to do the same with two meters with ID 1 and 2, it doesn't work. I have no idea how to proceed. I am attaching the code I have performed till now.
<?php
require_once("SocketServer.class.php"); // Include the File
$server = new SocketServer("192.168.1.5",5001); // Create a Server binding to the given ip address and listen to port 5001for connections
$server->max_clients = 247; // Allow no more than 247 people to connect at a time
$server->hook("CONNECT","handle_connect"); // Run handle_connect every time someone connects
$server->hook("INPUT","handle_input");// Run handle_input whenever text is sent to the server
/* //main loop
for($i=1; $i<=247; $i++) {
}*/
$server->infinite_loop(); // Run Server Code Until Process is terminated.*/
/*$server -> loop_once();*/
function handle_connect(&$server,&$client,$input)
{
SocketServer::socket_write_smart($client->socket,"String","");
}
function handle_input($server,&$client,$input)
{
// You probably want to sanitize your inputs here
$trim = trim($input); // Trim the input, Remove Line Endings and Extra Whitespace.
saveInput($input); // this function would save the values to database as it is received
$output = "65030063002F"; //65 -> Meter ID 101 in HEX 03 -> function 0063 -> start register 002F -> Number of registers
$hexad = hexToStr($output);
$hexad .= crc16($hexad);
echo $hexad;
SocketServer::socket_write_smart($client->socket,&$hexad,"");
}
function saveInput($input)
{
$res = strToHex($input);
for ($i=0; $i < strlen($res)-1; $i+=2)
{
$string[] = $res[$i].$res[$i+1];
}
if(hexdec($string[0]) > 0 && hexdec($string[0]) < 248) {
echo "Meter --> ".hexdec($string[0])."<br>";
echo "Function --> ".hexdec($string[1])."<br>";
$byte = hexdec($string[2]);
echo "Byte Count --> ".$byte."<br>";
/* $l=40100;
for($k=3; $k<($byte+3); $k+=2) {
echo "Register $l --> ".hexdec($string[$k].$string[$k+1])."<br>";
$l++;
}*/
echo "<br>";
}
}
function hexToStr($hex)
{
$string='';
for ($i=0; $i < strlen($hex)-1; $i+=2)
{
$string .= chr(hexdec($hex[$i].$hex[$i+1]));
}
return $string;
}
function strToHex($string)
{
$hex='';
for ($i=0; $i < strlen($string); $i++)
{
$hex .= str_pad(dechex(ord($string[$i])),2,"0",STR_PAD_LEFT);
}
$hex = trim($hex);
return $hex;
}
function crc16($data)
{
$crc = 0xFFFF;
for ($i = 0; $i < strlen($data); $i++)
{
$crc ^=ord($data[$i]);
for ($j = 8; $j !=0; $j--)
{
if (($crc & 0x0001) !=0)
{
$crc >>= 1;
$crc ^= 0xA001;
}
else
$crc >>= 1;
}
}
$crc = dechex($crc);
$order = str_split($crc, 2);
$order = array_reverse($order);
$crc = implode($order);
$crc = hexToStr($crc);
return $crc;
}
?>
The return values are all stored in Hexadecimal. Is there any better way to do this.
I want to send 65030063002FFC2C as the input to meter 101 and 66030063002FFC1F as the input to meter with id `102' and so on. Only if the meter ID gets a match at the meter input, it would return the corresponding readings to the server. I have been trying to figure this out for so many days, but since I am new to PHP sockets and with very little knowledge on same, it's hard.
So since no one yet answered, I did some digging and got a way around it. But it includes a loop. So there was a couple of meters. I could sent data to the meter using socket write and for loop. The part which didn't make the above code work, was while sending a meter 100s of request packets, it actually receives the first 8 bytes and rejects the rest. So I added a delay with sleep(1) and the code worked like charm