Create references to clock, I/O, register, FIFO, handshake, memory, or tag resources.
When Should I Use Refnum Controls?Use refnum controls when you want to access hardware resources in your subVI. With refnum controls, you can reuse the subVI and select different hardware resources each time you reuse the subVI. You can view available hardware resources on the SystemDesigner. You can also create additional resources, such as FIFOs or derived clocks, on the SystemDesigner.