To find your offline servers, go to:
TOOLS > ADMINISTRATION > POS Servers (Off-Line Servers)

From this location you can create a new offline server, update your existing pos servers or import off-line sales into your main IMerchant database.  

Clicking properties while highlighting a row will bring up the screen below.  View last sales upload or updates to the server.

Clicking Update POS will allow you to Rebuild Keyword Index on POS Server.

Click Import Offline Sales will show a confirmation message, click OK to import.