There are several ways to limit the input. You can right click the numeric control, click on properties, click on the Data Range tab, and set the min and max values. If max is set to 10, and the user tries to type in 11, it will convert to 10.
Another way is to check the numeric value using the In Range and Coerce function found in the Comparison palette. You can wire in a min and max value, and the numeric value. If the numeric is within range the boolean output will be True. If not within range, the boolean will be False and the Coerced output will be the min or max value that you specified.
A third way is to create a dialog vi that asks for user input. In this vi you can check the value that the user types in using the In Range and Coerce function, and if not in range then you can prompt the user to try again.
