What especially do you need, just logins and logouts or more?
The only thing I did was to hold statistics of concurrent usrs usage by realm/role or a login / logoutreport per realm/role.
The first part is just a parser, logging into the IVE Webinterface, parsing the content of the logged in userpage,
the second thing is based on syslogmessages from the IVE filtered by login + logout, read from a syslogd that writes all received messages in to a fifo from that my script reads...