Hi Bill,
Sounds like you may want to execute different segements of code depending on what inputs are being wired ot it. The best way to go about this is to use a control input that will represent the mode with which you can determine what case structure to execute.
If for some reason this does not work for you, another way to find out if an optional input has been wired is by comparing its current value to the default value of the control. However, you will have to set the default value to a value that you know the input will never have. I have attached a VI that shows you how to go about this.
Sincerely,
Feroz