Dynamic signal testing enhances functional testing at the breadboard, LabCar and yellow board phases

Breadboard testing, sometimes called LabCar testing or yellow board testing, is an important part of the automotive electronics design process. Breadboards do a good job of validating electrical harnesses, connectors, controllers, and basic electrical functions, but fall short when it comes to tests requiring dynamic signals. Traditionally, a vehicle’s electronics system only gets tested with dynamic signals later in the design process when the system is installed in a prototype vehicle.

Ideally, you want to perform dynamic signal testing sooner—at the breadboard phase. For example, testing powertrain controllers at the breadboard stage with simulated dynamic inputs allows you to identify system-integration issues with real components early in the design process.

Breadboard tests should allow you to test “vehicle” functionality of a variety of hardware and software configurations. You can do this by providing signals that convince ECUs that an engine is present and working. This test process is known as dynamic test board testing, or DTB testing, and the earlier in the development cycle you test with dynamic signals, the earlier you will find design problems. And, DTB testing costs much less than testing in prototype vehicles.

DTB testing improves on traditional breadboard testing by enabling you to:

• Simulate engine-running scenarios, by providing simulated crank and CAM signals.

• Perform electrical robustness & stability testing by simulating a number of different cranking scenarios.

• Perform system testing using automated and manual driving sequences.

• Perform user interface and driver controls testing.

• Measure quiescent and running current.

The benefits of DTB testing include:

• Finding failure modes.

• Compliance testing to many standards: ISO, GM, Ford, Mercedes-Benz, BMW, VW, and others as well as commercial, off-highway and rail vehicles.

• Testing early in design cycle reduces number of prototype vehicles that you must build.

• Costs less to own and operate than full hardware-in-the-loop (HIL) simulators.

Our DTB systems offer many advantages. For one thing, the unit contains all CPU, I/O conditioning, and measurement electronics, making them portable enough to be used with multiple Breadboards, LabCars, or Yellow Boards. As shown in the figure below, the DTB can be quickly connected to a standard test board.

The system’s built-in hardware provides signals needed to perform a variety of robustness tests, including cranking, transient bursts, ramping, and captured waveforms. This includes simulating engine sensor signals, such as crank and camshaft sensor signals.

Tests are monitored and controlled via Windows-based GUI VISUALCONNX software. This software allows a test engineer to use the GUI, canned scripts, or man-in-the-loop control to “drive” the test board or run virtual tests. This broadens the range of testing possible in a controlled environment and reduces the need for prototype vehicles or full-vehicle HIL testing.