An input parameter appears automatically as an input connector when the object is included in a module or composite block. The input parameter provides an input connection that allows you to bring in signals from other modules or from the field.
The following figure shows an example of an input parameter that has been added at the module level and how it looks on a function block diagram. Notice in the Parameter View that the INPUT parameter appears at the module level. If this module were used inside of another module on a function block diagram, you could directly wire a signal to that parameter.
Use the input parameter to make a parameter visible outside of its current level. If you had put this module with the input parameter into another function block diagram as a module block, you would see the input parameter as shown below:
Do not reference an external parameter that references another external parameter. (You can configure this, but it will cause you problems at run time.)