In this example, we will be modeling a two-way valve. We have three ports—A, B and C. Each is bidirectional and provides flow as shown in the following picture.
In order to support multiple states, two output functions have been defined on port A: one entitled Ab (which depends upon port B) and one called Ac (which depends upon port C). Both ports B and C have single functions that each depend upon port A.
What States should be Modeled?
The AB state activates bi-directional flow between ports A and B.
The real point in adding states such as the ones described here is to provide a control mechanism for testing and diagnostics. When creating tests, the states can be used to limit the paths that the test covers. Similarly, diagnostics will understand when tests activate different states, which could cause changes in diagnostic interpretation. For more about using states when defining Test Coverage, please refer to the topic "Testing with States."
