In MxVDev, we create Behavior Specifications, that is specifications of how a system should behave in response to certain stimulation.
Pass/Fail Judgment is the assessment of whether the actual behavior matches the expected behavior. In this section, we describe the options available while specifying pass/fail judgment criteria, without going into the details of how the assessment algorithm is implemented. We need to capture enough information when the Behavior Specification is created, so that the pass/fail judgment can be fully automated.
Expected and Actual Behavior
When specifying the behavior of a system, we define how we expect the system to respond to certain stimulation. This outcome is called the Expected Behavior Pattern. We can define Expected Behavior Patterns for some or all of the Output Signals that are used in the test. When we run the test, we take measurements. The measurements represent the Actual Behavior Pattern of the system. In MxSpecIt we specify the Expected Behavior Pattern in terms very similar to how the Actual Behavior Pattern will be measured. This makes the comparison process straight forward and intuitive. Pass/Fail judgment is achieved by examining the patterns to see if our pass/fail criteria are met.
With Patterns as a building block, we address Pass/Fail judgment in terms of:
•Pattern Matching - Do an Expected Signal Pattern and an Actual Signal Pattern match?
•Relative Time Criteria - Are the relative times between two Signal Patterns correct?
•Periodicity Checking - Are the times between transitions of a periodic Signal less than or equal to the Period Maximum?
Tolerances are key to assessing pass or fail. They define how close the actual behavior and the specified expected behavior have to match for a particular test to pass.
•Pass/Fail results checking can be enabled or disabled for each DataBlock. Use one of these methods:
oRight-click in the plot area of a Signal or multiple Signals, and select DataBlock->Pass/Fail Judgment (On/Off) from the context menu.
oSelect a single DataBlock, right-click, and select Properties from the DataBlock context menu. This method enables you to set other DataBlock properties in addition to Pass/Fail Judgment.
•The initial value check for a DataBlock can be turned on or off independently of its Pass/Fail analysis. See Check InVal in DataBlock Properties.
•Pass/Fail analysis may be performed On-the-Fly or Post Processing. See Project Settings–Pass/Fail Analysis.