$re = '~\[(?P<Manufacture>3G|EL)\*(?P<DeviceId>[0-9]{10})\*(?P<Length>[A-Z0-9]{4})\*(?P<Command>.+)[\]|,]{1}(.*)~UD';
$str = '[3G*2110620000*000A*UD]
[3G*2110620000*000A*LK,0,0,100][3G*2110620000*000A*LK,0,0,100]
[3G*2110620000*000A*LK,0,0,100][3G*2110620000*000A*LK][3G*2110620000*000A*LK,0,0,100]
[3G*2110620000*000A*LK,100]
[EL*2110620006*000A*LK,0,0],100]]]
';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php