Are you sure that your scope supports VXI-11 for TCP instrument communication? Given IP 192.168.0.1, this VISA resource descriptor will access a VXI-11 instrument (VXI-11 specifies the ports for communication in its specification, so you don't need this in the descriptor) "TCPIP::192.168.0.1::INSTR".
If your instrument does not support VXI-11 and you want access it via VISA using straight TCP to a specific port number (port 5555 in this example), use the descriptor "TCPIP::192.168.0.1::5555::SOCKET". Also, make sure you are running a newer version of VISA since VXI-11/ Raw Socket support hasn't been around as long as VISA has. If it's referenced in the helpfile (for viOpen) then it should support these resource descriptor formats.
Hope this helps.
Scott B.
GPIB Software
National Instruments
Message Edited by ScottieB on 04-11-2005 09:55 AM