Signal Patterns
Contents
A Signal pattern defines how a Signal changes throughout the execution of a TestCase. In a TestCase, Signal patterns fall into one of three categories:
•Specified patterns - A Specified (or commanded) pattern is defined for Stimulus (or Input) Signals. It defines how the Stimulus Signal should change as the TestCase executes.
•Expected patterns - An Expected pattern is defined for Response (or Output) Signals. It defines how the Response Signal must change over time if the TestCase is to pass.
•Actual patterns - The Actual pattern can exist for both Stimulus and Response Signals.
oStimulus Signals - The Actual pattern shows the actual transitions (times and values) that the Stimulus signal underwent. This is valuable for recording a test sequence, and is also used to measure Quality of Service. Quality of Service provides a measure of how accurately a TestCase was executed.
oResponse Signals - The Actual pattern shows the actual behavior of the System Under Test, for that Signal, as the test executed.
Specified and Expected Signal pattern data are stored in a sequence of one or more DataBlocks. Actual patterns are stored not in the TestCase file, but in the Scenario log file (<ScenarioName>.mxlog).
Signal patterns are displayed differently in TestCases, depending on the type of the Signal.
•Numeric Signals - The Signal pattern is plotted as a time/value graph. You can change the minimum and maximum display values. For Continuous Fixed Signals, you can change the value y-axis units to be in either Engineering Units or Counts.
•Event Signals and Messages - Events are displayed as a spike at the point in time that the event occurred. Messages are displayed as a spike when the message is transmitted or received. If there is a data component to the message, it can be seen in a pop-up window during a mouse over, in the Transition List, or by double-clicking the transition.