Overview
A Real-Time Test (RTT) system is used whenever a simulated environment needs to run deterministically to stimulate a device under test (DUT). In this document, a framework for performing Real-Time Test will be described.
This content is located in the ni.com Examples repository:
Code and Documentation: https://forums.ni.com/t5/Example-Code/Reference-Design-for-Real-Time-Test/ta-p/3992168
Support and Discussion Forum: https://forums.ni.com/t5/Real-Time-and-Control/Real-Time-Test/m-p/955623
Background
Functional test is a critical step of the design cycle of a product. Whether it is in V&V or manufacturing, functional test requires exercising the device under test (DUT) under various conditions to validate its design and functionality. To achieve this, a test system has to generate the stimulus signals that represent the real environment the DUT will exist in. The test environment can vary from the simulation of a complex device using a mathematical model, to a series of steps and conditions that stimulates the DUT based on a test profile. Generating and responding to these simulated real world signals in a deterministic and repeatable fashion often requires the RTT system to use a deterministic real time OS.
The RTT system’s software is typically composed of several components that perform a specific task before, during and after a test. These components are responsible for reading and writing to physical channels, save test results into a file, and execute a test sequences, among other things. Below is a description of how to implement the different components of an RTT system.
Reference Design
The Real-Time Test reference design consists of three high level components. The RTT Engine component executes the RT test profiles by generating different stimuli and analyzing the DUT’s response. The test executive component is responsible for automating the test, analyzing the results, and displaying a comprehensive report to the operator. The host component is used to monitor variables as well as to access and display parameters and signals as the test is performed.