VISA session and controling my instrument

[very_confused]

I've just started using Labview, and to begin, I want to perform a simple operation on my instrument. I have a couple of questions about that:
a/what is a VISA session and how do I configure it?
b/I know that Labview is "talking" to my instrument, but it's not talking correctly. My instrument just locks when I use the getting started.vi. Say I want to change the frequency from the default 1kHz to 2kHz, don't I just have to change that value in getting started.vi and then run the program?
c/where can I find info on all those VIs each instrument driver has? I know that pressing ctrl+h gives some, but there are so many of them. Is there anywhere I can find more descriptive, detailed information? And, which is the VI that shows up
on the main front panel, that the user can work with? I've tried all of them, but none seem to be that particular one.
Your directions would be very much appreciate.

[BJD1613]

VISA stands for Virtual Instrument Software Architecture. What visa allows you to do is contol various types of interfaces such as serial, vxi, pxi, and gpib with a simple vi's in LabVIEW such as open, read or write, and close functionality with specifying the interface in the resource name. What type of interface is your instrument talking on? You can find information from first the manufacturer who made your instrument. Alot of time they might actually have a labview driver developed for you. You also can find these types of driver on this site at www.ni.com/idnet. You can use the expanded help by selecting show more help in the context help window if there is more information. Sometimes there isn't more information dependent on who developed the driver. You
can goto the browse menu item and select show vi hierarchy. This will show you the structure of the instrument driver and the vi that is at the top of the tree will be the vi that you should be working with. Hope this helps.

[very_confused]

thank you for the reply... although I know what a VISA is, I was wondering what a "VISA session" is exactly and how I might be able to configure it. About "show VI hierarchy", that's exactly what I'm looking for. should that be in the Browse menu of the block diagram? b/c I only have "This VIs callers" and "This VIs subVIs" that can be used when I've dropped a VI onto the block diagram.
thanks again,