The ACjr wont have an IP address. Easiest to use the Aquaconnect software from Neptune (a free download for the lite version), or can use the Windows built-in application, hyperterminal - hypertrm at the DOS prompt. Give it a name, the 'connect using' will likely be a com port (com1 typ, but can be another depending on serial port setup.) Port settings should be 9600,8,n,1,none. GL!