- dechex: documentation ( source)
- hexdec: documentation ( source)
<?php
//$DXPcmd = array(0x55,0x82,0x10,0x31,0x00,0x51,0x96);
$DXPcmd = array(0x55,0x82,0x10,0x31,0x00,0x51);
$DXPcmd = "558210310051";
$SUM=0;
for ($i=0; $i < strlen($DXPcmd)-1; $i+=2){
$SUM += hexdec($DXPcmd[$i].$DXPcmd[$i+1]);
}
$NOTSUM = ~$SUM;
echo dechex($NOTSUM);
$CHKSUM = $NOTSUM & "11";
echo dechex($CHKSUM);
?>