What I did was, I used the NI-MAX 2.0.3.6 and NI-VISA 2.5 to configure the Target Device as TCPIP0 with it's Address and Socket number or Port number. After that I created a simple VI with VISA OPEN, WRITE, READ and CLOSE. On the VISA Resource name you can use "TCPIP0::IP-address::PORT#::SOCKET" and Right Click on the Resource and select VISA Class->I/O Session->TCP/IP SOCKET. and you are all set to talk to the instrument. Make sure when you write or send a string to the instrument add "Carriage Return" with it. Normally, GPIB/RS-232 does not require this "CR".