Radacct was empty

Hi all..I've install nocat auth and i made my accounting (freeradius)server
separated between machine. It's means that nocat authen server and
freeradius are different machine. It's seems ok since nocat can read
user and password from mysql that inside the radius(freeradius)
machine. But, the problem is, my radius server cannot doing
accounting. radacct in radius log are empty even my radacct tables in
mysql also empty. I don't know what's going on. Anybody can help me ?