Hi Ladis,
to use cron you have to execute cron.php as frequently as your most frequent job.
It depends on system how to set up system cron, but you have to execute
php -f <epesi_dir>/cron.php
Then your module has to implement cron() in common. Return array with function from common to execute => minutes frequency.
Make sure you have the latest version of EPESI - 1.5.6.
class MyModuleCommon extends ModuleCommon {
...
public static function cron() {
return array('my_function' => 60*24); // 60minutes = 1hour x 24 = 1440 = daily
}
public static function my_function() { ... }
}