If the no concat flag is set this just outputs a tag for each file. There are two ways to set the no concat flag. The first is in the site configuration file by setting $arrConfig['NoConcat'] to false. The second way, just for testing purposes, is to add raw=1 to the query string.
In order to set up the correct routing for the concatenated file output the following routing line needs to be added to the site configuration file.
$arrConfig['Routes']['^/concat/(css|js)/([0-9]*)/([^/]*)/[a-z]+.(css|js)$'] = '/concat/$1/version=$2/files=$3/';
The version number in the routed URL is used for cache busting for both the application's internal cache and the users' browser cache. Any time a change is made to a CSS or JS file that's run through the concatenator it's a good idea to increment the version number in the site configuration file. The version number is stored in the $arrConfig['CssVersion'] and $arrConfig['JsVersion'] variables.
$objConcatHelper = new ConcatHelper();