Lucent Reduces Process Test Time by Half Using TestStand and LabVIEW for a HASS Test Station

Author(s):
Richard E. Mattila - Lucent Technologies

Industry:
Telecommunications

Products:
TestStand, LabVIEW

The Challenge:
Developing a common operator interface capable of testing a wide variety of Lucent Technology Core and Edge Multiservice WAN Switch products simultaneously.

The Solution:
Customizing the LabVIEW example operator interface supplied by TestStand 2.0 and using the LabVIEW Internet Toolkit for data collection to simplify implementation of the first highly accelerated stress screening (HASS) test solution.

Meeting Demands of Current and Future Test Development Efforts
The Test Automation Group, a division of the Supply Chain Networks Test Engineering department, develops and deploys test solutions used by international contract manufactures to build Lucent Technologies Core and Edge Multiservice WAN Switch products, such as the CBX 500 (R) Multiservice WAN Switch. We can use HASS to test virtually any communications or PC-based products. TestStand and LabVIEW enable us to meet the demands of current and future test development efforts while substantially reducing test execution time. TestStand 2.0 provides a test management environment, where we execute the TestStand sequences from the operator interface and get data collection results. We modified the TestStand off-the-shelf LabVIEW example operator interface VI to fit our needs and reduce development time. TestStand also fulfilled additional requirements such as flow control (preconditions, pretest, posttest, and looping), plus user-management login, providing different program features to operators and administrators.

The ability to test multiple board types simultaneously is critical to maximize system throughput. The HASS system can test a maximum of 12 chassis with 16 boards in each unit under test (UUT). In the first implementation, HASS testing required controlling and running a temperature profile in an environmental test chamber to stress the boards over a range of temperature and vibration. We developed provisions to run different test chambers without affecting the operator interface code. The HASS testing system can run boards under test completely unattended.

The project consists of an operator interface, TestStand test sequences, and code controlling both a temperature chamber and power supplies. The chamber interface uses DataSocket communication and accepts generic commands from the operator interface and converts these commands to the DLL function calls of the test chamber. The chamber interface receives and translates generic power supply commands. This ensures the operation remains unchanged even if we replace the chamber or power supplies.
The LabVIEW operator interface communicates with the TestStand engine as an ActiveX client and passes data through parameters to the TestStand sequence once they run.

When running the program, the operator selects each UUT and starts the test, as can be seen in the system diagram. The operator interface then executes a TestStand sequence, reading the card slots and reporting the board types back to the operator interface. The operator interface VI passes these two sets of arrays as parameters to the TestStand Atsmain1.seq. Automation calls in the Atsmain1.seq cut down on the amount of code needed to be written. The Atsmain1.seq then launches new parallel executions for each UUT and bunches sequence files, where a test sequence file runs in a new thread for each selected board slot. As UUTs complete their testing process, a user interface message communicates to the operator interface, signifying that this UUT is complete, and reports the results for the UUT. The operator interface then transmits the test results to the data collection system via hypertext transfer protocol (HTTP) using the LabVIEW Internet Toolkit. If the database connection fails, reports are temporarily saved until the HTTP connection resumes. We can also print reports to the network printer or display them on the test PC screen. Any program or communication errors automatically save to an error log file and display on the operator interface front panel error report indicator.

Prior to the implementation of the HASS testing system, we used environmental stress screening (ESS) testing. The ESS testing system limited us to testing products over temperature only with no automated data collection. With the TestStand-based HASS system, we can test multiple temperatures and vibration levels simultaneously. As a result, the HASS system catches more board process problems, such as cold solder joints on components, enabling us to improve the manufacturing process substantially.

The HASS system can help reduce the amount of boards returned to the manufacturer, saving a significant amount of money by detecting temperature and vibration-related problems earlier in the process. In addition, the new HASS testing system reduced our process test time by half, resulting in a substantially lower testing cost per unit.

For more information,contact:

Richard E. Mattila

Test Technology Engineer

Lucent Technologies

4 Robbins Road

Westford, MA 01886

Tel: 978-399-0406

E-mail: mattila@lucent.com

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