linelog and accounting informations

Hello every body, i got a question about linelog : Indeed i want to log and store any informations . I'm focusing on accounting data. The filename is linelog under logdir. I create linelog under /var/log/radius/linelog myself with rights 644. . When i run freeradius, there is no data filled under after a sucessful authentification and connection. Do i miss something ?Are there any things to do to ? Here is linelog on attached file. Cheers.