Purpose

This example demonstrates how to override the PreUUT Model callback sequence to simulate scanning a serial number and performing a database query. When you do not override the PreUUT callback, the default process model prompts you to manually enter a serial number.

Example File Location

<TestStand Public>\Examples\Modifying Process Models\Overriding Model Callbacks - Sequential Model\CVI\Overriding the PreUUT Callback.seq

Highlighted Features

Callbacks

Major API

None

Prerequisites

You must have the LabWindows/CVI Run-Time Engine installed and you must configure the LabWindows/CVI Adapter to execute steps in-process. If you want to use the Execute Steps in an External Instance of CVI option, you must have the LabWindows/CVI development environment installed.

How to Use This Example

Complete the following steps to review the sequences and steps in this example.

  1. On the Sequences pane, select the MainSequence. The MainSequence contains four Numeric Limit Test steps.
  2. Select Edit»Sequence File Callbacks to launch the Sequence File Callbacks dialog box, in which you can select a callback to override. For the PreUUT callback, the Present column specifies yes. Click OK to close the Sequence File Callbacks dialog box.
  3. On the Sequences pane, select the PreUUT callback. The IdentifyUUT step, which uses the C/C++ DLL Adapter, calls a DLL to simulate scanning a serial number and performing a database query.
  4. Select Execute»Test UUTs to run the sequence. The PreUUT callback executes instead of the PreUUT callback in the process model, so TestStand does not launch the default UUT Information dialog box for you to manually enter a serial number.

You can click the Stop Testing button at any time to terminate the execution.