Benchmark Electronics Uses NI TestStand and PXI Platform to Create Standard Tester

Author(s):
Paul Schaffner - Benchmark Electronics

Industry:
Industrial Controls/ Devices/ Systems, Telecommunications, Medical Devices

Products:
LabVIEW, PXI/CompactPCI, TestStand

The Challenge:
Designing and implementing a standard test platform to meet a wide range of product functional test strategy needs. Benchmark Electronics, an electronics contract manufacturer, provides telecommunication equipment, computer, industrial control equipment, test instrumentation, and medical device services for OEMs.

The Solution:
Using the National Instruments PXI platform and NI TestStand to develop a test system that accommodates a variety of board- and device-level parametric testing and stimulus/response product tests.

Standard Test Platform Creation

We needed to design and implement a standard test platform to meet a wide range of product functional test categories. We did not have specific requirements – just generalizations to deliver the best instrument capability with a low cost and small production footprint. The test solution had to be modular to accommodate quick component change-out times during calibration and repair cycles. We needed maintainable test application software to support the multiple custom applications our customers often provide to test products. In addition, we needed to deploy the test platform in numerous locations both inside and outside the United States.

PXI Instrumentation Suite

We had to strike a balance between desired capability and tester cost. At a minimum, the test solution had to provide basic parametric measurements as well as basic stimulus and response capability. Benchmark Electronics test developers selected instrumentation that met 70 percent of the product test requirements, which focused heavily on parametric testing. Other large-scale system integration testing was not within the scope of this type of test approach. We typically can meet the remaining 30 percent of our product test needs with instrumentation choices tailored to special product requirements.  

The chassis is controlled by an industrial PC with a MXI-3 link. The instrumentation is automated using NI TestStand for test flow control and National Instruments LabVIEW for low level test code. We used the following NI instrumentation in the standard platform definition:

• PXI-1045 general-purpose 18-slot chassis (with rack-mount kit)
• PXI-8330 MXI-3 PXI/CompactPCI controller
• PXI-6508 96-bit digital I/O module
• PXI-4060 5½-digit digital multimeter
• PXI-5112 100 MHz digitizer with 32 MB per channel
• PXI-5401 function generator

We have ample room to add instruments for specific needs without disrupting the standard instrument suite. These include:

• PXI-1407 and PXI-1409 image acquistion modules
• PXI-4070 6½-digit digital multimeter
• PXI-5620 frequency domain digitizer
• PXI-5600 2.7 GHz downconverter
• PXI-5610 2.7 GHz upconverter
• PXI-5421 arbitrary waveform generator

Software Standardization through NI TestStand User Interface

Benchmark Electronics test developers adopted the standard NI TestStand interface with only minimal adaptation, which facilitates easy version upgrades.

One NI TestStand modification included a pull-down menu option to connect the tester to the Benchmark Electronics process-monitoring software called PFS, or Process Feedback System. When activated, PFS passes all test pass/fail statuses from NI TestStand to the monitoring system without operator intervention.

We also implemented another NI TestStand modification to facilitate simple maintenance and monitoring features for product-specific fixtures. For example, we can use a utility to add and change fixture identification numbers via the interface.

In the past, Benchmark Electronics test developers have used custom test executives with limited success. But we took advantage of the NI TestStand user interface, test-flow control, configuration and variable loading, and ability to run custom stand-alone executables in a variety of native compilations.

Deployment through Target Testers

We dubbed the test platform the “Target Tester” because we developed it to fit a test requirement niche Benchmark Electronics needed for low- to medium-complexity test solutions with a common look and feel across a variety of cultures within the company. At the time of this writing, we had installed more than 25 Target Testers and standard tester versions at Benchmark Electronics locations worldwide.

We centrally control and distribute a spare stock of instrumentation as needed for upgrades or repairs. Benchmark Electronics developers rely on sustained engineering support for product and tester debugging. If new developments or low-level changes need to be made, the engineers often work through the Benchmark Electronics network to access and control Target Testers remotely.

Cost Savings through a Standardized Solution

The Target Tester standard platform approach is successful for Benchmark Electronics because it uses software and instrumentation standardization to the benefit of both test developers and production users. In addition, Benchmark Electronics customers realize a net savings by using available test capacity over the development of a wholly new test solution.

For more information contact:

Paul Schaffner

Benchmark Electronics

4065 Theurer Blvd

Winona, MN 55987

Tel: (507) 453-4628

E-mail: paul.schaffner@bench.com

Web:  www.bench.com

 

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