I’m starting out on C# and need some guidaance. My goal is to develop applications that will control/take measurements/gather data from RF lab instruments (signal generator, vector network analyzer, spectrum analyzer). My issue is to what commands are used by C# to actually talk to the instruments? In my setup instruments are connected to the computer using usb ports and Ethernet hub. I have installed Agilent’s I/O device drivers (VISA). What books/sites/articles are useful for this purpose?