$re = '`([^\s=/]+/[^\s=]+)=(.*?)(?=\h+[^\s=/]+/|$)`m';
$str = 'ALARM_ID/I4=1010001 ALARM_STATE/U4=eventcode ALARM_TEXT/A=WMR_MAP_EXPORT LOTS/A[1]=[ STEFANO ] ALARM_STATE/U1=1 WAFER/U4=1 VI_KLARF_MAP/A=/test/klarf.map KLARF_STEPID/A=StepID KLARF_DEVICEID/A=DeviceID KLARF_EQUIPMENTID/A=EquipmentID KLARF_SETUP_ID/A=SetupID RULE_ID/U4=1234 RULE_FORMULA_EXPRESSION/A=a < b && c > d RULE_FORMULA_TEXT/A=1 < 0 && 2 > 3 RULE_FORMULA_RESULT/A=FAIL TIMESTAMP/A=10-Nov-2020 09:10:11 99999999
';
preg_match_all($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