You may not have NI VISA Interactive Control.
But you do have the Keithley Communicator.
To ensure that you can communicate with VISA, open the Keithley Instruments -> Keithley Communicator.
Then click on the Open Instrument button and enter or choose the VISA resource that matches your 2700 setup in your case I believe this is ASRL3::INSTR and then press the OK button.
Then enter *idn? in the lower portion of the window and press the Run button.

- KeithleyCommunicator_1.JPG (23.54 KiB) Viewed 28768 times
If all goes well you should see the instrument respond...

- KeithleyCommunicator_2.JPG (28.05 KiB) Viewed 28768 times
If this works, then the problem is with your program..I don't know much about your program, but be sure it is set for 32-bit or x86 target and not 64-bit x64 CPU. You might look - for some examples we have posted and try them out to see if you can get something to work:
http://www.keithley.com/support/keidoc_ ... le+Program]