A dedicated VI for a function would typically have the CMD as part of a format into string and you would have front panel controls for the numeric and VISA Resource Name. It sounds like you would need an additional one for the address. This string would be passed to a VISA Write. If the command returns data, you then wire VISA Read. If your instrument is typical and uses a termination character such as a carriage return, it is silly to do like the example and have a delay and a VISA Bytes at Serial Port.
Look at the 34401 Initialize function where the idn command is sent and immediately read. Look at the reset function where just the command is sent with no read being done.
As another example, you have an enable function where it would make more sense to the user to pass a true/false instead of 0/1.
