Subsystems and Pin Maps

For example, if you connect a pin to a shared instrument but a code module does not require the pin, you might be able to execute the code in parallel. After determining the sites to synchronize, the ECU Multi Test and the ECU Action steps wait until those sites reach the synchronization point or become disabled. The step then calls a sequence and passes a PinMapContext object that contains the information about the sites for the called sequence.

A subsystem is a part of the test system that can operate independently. Subsystems are defined dynamically based on the active sites, the flow of each test socket, and the instrumentation required to conduct a test.

The following figure shows two NI-SCOPE instruments for which channels must operate together and one power supply instrument that can operate four independent channels. Each DUT includes an A, B, and C pin. Each pin A and pin B connects to an NI-SCOPE instrument, and each pin C connects to a power supply.

The test setup in the previous figure includes two subsystems that can operate independently: a subsystem that contains the top half of the figure, and a subsystem that contains the bottom half of the figure. If a test needs to use only pin C, you can break the test setup into four subsystems, one for each site.

By default, the ECU Multi Test and ECU Action steps assume that a code module uses every DUT pin and no site relays. The performance of the tester can be improved by specifying only the pins that the code module uses.

The following figure shows a similar situation as the previous figure but replaces the two independent NI-SCOPE instruments with two NI-SCOPE instruments that are grouped together. By default, the ECU Software Toolkit groups all NI-SCOPE instruments together.

This test setup includes a single subsystem when using any of the digital pins (A and B). For test steps that use pin A or pin B, the ECU Software Toolkit executes the test code module in a single TestStand test socket because all NI-SCOPE channels must operate together. The NI-SCOPE driver performs some operations on the channels in parallel to achieve improved performance. As in the previous example, if a test uses only pin C, you can break the test setup into four subsystems.