You can remote control the program through UNIX socket or TCP socket.
To control it through TCP socket, you just connect with telnet to the machine, where is sim running with port used in configuration of plugin:
telnet 127.0.0.1 3000
note: 3000 is the default port
Then use HELP command to see what you can control.
>help STATUS set status INVISIBLE set invisible mode MAINWINDOW show/hide main window SEARCHWINDOW show/hide search window QUIT quit SIM CLOSE close session HELP command help information ADD add contact DELETE delete contact OPEN open contact FILE process UIN file CONTACTS print contact list SENDFILE send file GROUP get group name SHOW open unread message SMS send SMS