Tired of chasing down hundreds of test parameters? PathWave test executive for manufacturing (PTEM) has the answers
Managing test parameters can be a nightmare. A single test consists of at least 4 to 5 parameters ranging from expected and measured values, threshold limits to test targets and resources. Multiply these with the number of test steps you have in your test plan, the total number of test parameters that you need to work with can be significantly high, making it a mammoth task to check and update these parameters.
PathWave Test Executive for Manufacturing (PTEM) provides you with a convenient way to manage your test parameters through parameterization. The concept of parameterization is to merge similar parameters into a secondary parameter so that you can check and update all of them from a specific location instead of having to step through each of the test steps. Parameterization also simplifies the transfer of parameters values between the test plan and its subsidiary test plans, like subroutines. A single point of control makes it easier to manage the secondary parameter and significantly reduces the chances of incorrect entries. In PTEM, parameters in the test steps are considered primary parameters. Regardless of input or output parameters, you can parameterize them at the parent test step level or at the test plan level as part of the test plan settings.
An example where parameterization helps is a test plan that consists of multiple test steps that uses a set of test limits. The testplan can be performing the same type of test, like voltage measurements on multiple targets or devices under test (DUT). Or it can be making the same measurements on the same DUT while varying test stimulus throughout various stages of the test cycle.
Figure1: Example of an LED measurement test plan that uses parameterization.
The test plan in Figure1 has a set of test steps that measures the color wavelength of the group of red and green LEDs on the DUT. Each of the LEDs has its own test step and because the color of the LED is the same within each group, they use the same set of test limits. During the setup stage, it is inevitable that we will need to adjust the test limits. It will be tedious to manually click on each test step to change its test limits, not to mention the high probability of typo errors when the number of steps increases.
Figure2: Select where to parameterize using the right click menu on parameter.
We can parameterize the test limits of the test steps of each group at their parent step so that all test steps in a group will get their limits from their parent step. Once you change the limits at the parent step, all the child steps will inherit the new limits.
Options to parameterize are readily available in the right-click menu of every parameter. You just need to select between parameterizing at the parent step, or at the test plan itself. In Figure 2, we parameterize the Maximum value of the “Test D1R” step to the parent step “Test Red Wavelength”.
Figure3: Test step setting of parent step holds the secondary parameter.
Parameterizing at the parent level links the primary parameter in the test steps to the secondary parameter found on the parent test step. In the test step setting of the parent, you can find the secondary parameter which presides over the parameterized child steps. The secondary parameter on the parent test step is accessible to all its child steps. So, all the child steps of “Test Red Wavelength” can parameterize their test limits to the same secondary parameter. All you need to do is to update the secondary parameter and the child steps will get the new values.
Figure4: Parameterizing at the test plan level places secondary parameter onto test plan settings.
On the other hand, parameterizing at the test plan level links the limits directly to the test plan settings, where it becomes accessible by all test steps in the test plan and subsidiary test plans or subroutines. At the test plan level, the secondary parameters are accessible to all test steps within the test plan, and they can be passed in or out of any subsidiary test plan. This serves as the method to transfer values between the main and subsidiary test plans.
For the secondary parameters in the parent test steps, you can assign them to user variables and let the test plan execution decide what values to use. This increases the flexibility for you to manage the test parameters.
The bottom line is that it is easier to work with one set of parameters in one location, than with multiple sets of the same parameters scattered throughout the testplan. This reduces the test development time and minimizes the probability of mistakes. Parameterization significantly reduces the number of parameters in a testplan so that troubleshooting becomes easier.
If you are interested to learn more about PTEM parameterization, check out the demo videos on Keysight Hands-On channel on YouTube.
You are welcome to contact me if you have any questions or comments.
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