Do you mean the address of an instrument or the address of the controller? The controller gets installed with a default address of 0. Assuming you have an NI GPIB board, you have a program called Measurement and Automation Explorer. With MAX, you can configure the controller and change it's address. There is a Devices and Interfaces listing in MAX. Yuo can expand this and right click on the controller listed and select 'Scan for Instruments'. This will return a list of all instruments found and their addresses. You can always check the instruments themselves. Some have a dip switch that is used to set it and some you view/set from the instrument's front panel. The manual for each instrument should explain all of this. When you write your program, if you use VISA (recomended), you have a VISA Resource Name control that is used to specify the address. You can click on the arrow on the right side of the control and get a list of all available instruments.
