Writing Test Plans with RI System Software
|Creating a New Test Plan|
Understanding Test Plan Structure
Building a Test Plan
Viewing the Tester Configuration
Compiling & Running Test Plan
Viewing Test Results
Release to Production
The RI System uses a system controller with a grafical user interface where a designer can assemble tests by working with buttons instead of writing source code. The grafical test plans are compiled into optimized machine code that is used to control the instruments in the system. This chapter introduces the test plan developer to the Test Plan Editor and gives instructions for building a basic test plan. Test Plans define the system state for every moment the device is under test. This chapter covers the steps needed to prepare a test plan suitable for testing and using the results for a simple device. Complex devices may require additional training, so an Advanced Test-Plan Design course is offered by RI to cover those issues.
Typical Test Plan
A typical test plan panel is shown above with a VNA Measure S-Parameter Button. Each Button is an object (software code) that is capable of certain tasks defined in the inside of the double box. In this case, a MEAS button performs a measurement. This means that this Button or Object is capable of performing measurements and will pass on the data and its data type to whatever measurement is defined in the inner box. The definition is selected from its internal list determined by the ATE system. This is called the "owner" and it is displayed in the outer top left corner of the double box button. In this example, the owner is the VNA. The VNA is a virtual instrument and it has a specific set of measurements available. In this example, we are using the fundamental measurement of S-Parameters.
The measurement state buttons on the left side of the test plan tell the system the conditions at which the measurements are to be made. In this example, the Source1 Power level set to -15 dBm and measurements are to be made with Source1 Frequency starting from 1000 MHz to 2000 MHz in 11 steps, and DutControl voltage Vcc1 from 2 to 5 Vdc in 5 steps (a total of 55 measurement states). The S-Parameter measurement button, shown in the middle of the test panel, tells the VNA to perform the S-Parameter measurements at each measurement state. The System's CALC button computes the data for just S21 and the SAVELOG Gain_CW button connected to the Calc button tells the system to save the test results in the local SQL database or data logger using Gain_CW as the column label and format it as a Log. This simple data flow structure also instructs the system to save into the database the complete measurement state/status, event time, the unique part number associated with each part, the operator’s name/ID number and the site location ID name/number. Later we will see Data Flow Diagrams which also contain Calculation buttons and Local Variable Save buttons.
Test System Viewer Window
Test plans are created by copying buttons from Test Instrument Panels into the paste buffer and then adding the buttons to a new test plan panel. For example, to add the S-Parameter measurement button you select the VNA instrument and select the MEAS - S-Parameter button (highlight the button), and add the button to the test plan. The process takes just a few seconds. It is that simple and easy to create tests.
Measurement State Buttons
The Test System Viewer panels also provide the measurement state buttons. For example to select the source power state button in the previous example, you select the Source1 instrument and the state button types (shown above), select the POWER state button (highlight the button), and add the button to the test plan.
The test system software provides Test Instrument panels for each physical instrument in the system (such as the RI Test Head, RI System Receiver and the Microwave Sources) and each virtual instrument defined by the system (such as the noise figure meter, vector network analyzer, gain compression meter, etc.)
Test Plan Debug Tools
Run From the Test Plan Editor
Breakpoint and Step Control
Interactive Control Panel
State Displays and Statistic Monitoring
Multidimensional Data Viewers
The test system software has powerful debug tools available that allow a test plan to stop in mid-stream, alter the settings, resume test and display the test results using one of several different data viewers. The rectangular data viewer displays the test results for a test plan like the example measuring Gain of a 2 port LNA from 1 to 2 GHz in 11 frequency steps and at 5 different DC bias levels from 2 to 5 volts. Each bias level will typically be represented by a different colored trace to distinguish the results. The x axis is normally frequency, formatted with linear scaling. The Y axis is usually amplitude, but depends on the test data and can be formatted on the fly with the Y axis center line and the Y axis scaling per division user definable or autoscaled. The data viewers will be described in detail later.